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Fan Coil Units Service Manual

1. OKW 1PH SCHEMATIC DIAGRAM FIELD POWER WIRING DISCONNECT PER NEC DISCONNECT PER NEC FIELD POWER WIRING 1 SISS SEE RATING PLATE 1 GND 1 FOR VOLTS 8 HERTZ 1 SEE NOTE 1 1 2 i SEE RATING PLATE VAPEUR YEL FOR VOLTS amp HERTZ BLK PLUG SEE NOTE 1 YEL VEL 7 LS5 YEL COOLING CONTROL WIRING COOLING CONTROL ONLY 184 HTB4 BLK BLK 80117 if AUX HEAT RANGE L BEDA 153 HTR3 O TSO 6H H 5 lo SIZE 24VAC YEL 162 2 BLK BLU YEL 7H HK L3 OO Cn b SUE 150 WIR HEG A C HP COMFORT 2 D 1 Pa WW 9 G r pg NEL AC HP DELAY ON OFF LVTB 0 30 30 30 30 30 0 0 GH 11 CIC _ BLU 7 3 J xp 000000 pg 12119 Be e 8 7 6 598 2 RECP 2 iD BRN PLUG 1 RED LETRAN J RED 7 AUXI FoR O
2. LOCATION NORMAL READING PURPOSE L1 and L2 208 230 vac Main power supply input to fan coil L3 and L4 208 230 vac Power to electric heaters 9 pin connector 7 and 9 208 230 vac Power to smart control T1 and T3 208 230 vac Power to transformer SEC1 and SEC2 24 vac Power from transformer secondary R and C 24 vac Power from transformer secondary G and C 24 vac Call for continuous fan signal from room thermostat Y and C 24 vac Call for heat cool signal from room thermostat Signal to energize reversing valve from room thermostat cooling Also present O and 24 vac during defrost W2T and C 24 vac Call for electric heat from room thermostat W2D and C 24 vac Defrost initiation signal from heat pump Output Voltages LOCATION NORMAL READING PURPOSE HI and F1 208 230 vac Power to blower motor high speed LO and F1 208 230 vac Power to blower motor low speed Y and C 24 vac Power to energize contactor in heat pump heat and cool modes 9 pin connector 24 vde Power to energize SEQ 1 1 and 4 NOTE Sequencers use DC voltage 9 pin connector 2 and 4 24 vdc Power to energize SEQ 2 9 pin connector 3 4 24 Power to energize SEQ 3 vac volts AC vdc volts DC 45 Are line voltage fuses FU2 good Is LED on control on steadily or not at all Both of these indications signal a possible board failure Is 208 230 v power available to control across pins 7
3. CONTROL CONNECTOR A94079 Fig 14 FK4B ICM2 Motor Step 1 Integrated Controls and Motor ICM2 The ICM2 is similar to the ICM1 used in FK4A series units but cannot be used as a replacement without some modification to FK4A unit Consult SMB 93 0052 for motor conversion kit The electronics of motor are built into rear of motor deriving the name ICM See Fig 14 An ICM is first fed high voltage AC power through the 5 pin connector The AC power is then rectified to DC by a diode module After rectification DC signal is electronically communi cated and fed in sequential order to 3 stator windings The frequency of communication pulses determines motor speed The rotor is permanently magnetized An ICM is powered with high voltage at all times The motor will not run with high voltage alone Low voltage must be applied to control plug to run motor Step 2 PCB Layout and Description NOTE Layout of actual PCB is depicted in Fig 15 and 16 The control is a single PCB which interfaces a variable speed ICM2 with other system components Power for system is supplied from a 230 vac 60 Hz line Class 2 voltage 24 vac nom used for thermostat connections is derived from a transformer located in close proximity to control The 19 primary and secondary of transformer are connected to control board The 24 vac secondary circuit includes a socket soldered into circuit at SEC2 to r
4. AdS YIN IH NOWNOD 48 HLN MOT 5445 LVLSIGINNH OL 548 OL 13 1 01 06026 Ve 898S0 c qavoa LINDYID 89 Hd H3MOd 01315 H3MOd AHOLOV 7910 0191 TWNIWYAL GAMYVNNO O SSS OL OVA Q amp 63 NONINOO NOWWOO HOLON 9 1 033 5 YOLOW NVA 14 160 6 Sy Aejay pue 14 161 411 89890 LN31V1 83385 AV T3H AV T3G LVLSCINNH LSH LINDYID 0 Hd H3MOd 91913 ONIYIM H3MOd AHOLOVJ3 1410 91915 TWNIWYAL TWNINYSL 39v L 10A A QdS HLN IH Qqaads H3MOT OL ON S IVNIINH3L 28 1 222 7 SANIT G
5. SEC2 x 5 AUX1 HUM1 AUX2 HUM2 GRY DIODE LOGIC CONTINUOUS FAN AUX HEAT KW CFM AC HP SIZE SYSTEM CFM ADJUST DELA A96431 Fig 24 Easy Select Board Schematic Table 7 Connections on Single Barrier Strip Mounted Cross Slotted Captive Binding Head SCREW TERMINAL DESCRIPTION W2 Connection for W2 signal from thermostat Connection for signal from thermostat W1 for signal from thermostat or high speed compressor operation G Connection for G signal from thermostat Connection for signal from thermostat L This connection is a field termination for use in connecting L lines of thermostat and outdoor unit together There is no connection of this terminal with control circuity 1 Connection for low speed compressor operation R Connection for R signal to thermostat 24 vac Connection for terminal to thermostat 24 vac common CFM SELECT CONFIGURATION TAPS The CFM Select taps are used by installer to configure system The ICM2 is capable of discerning half cycle sine wave on some of its inputs and uses this capability to modify its ope
6. X Carrier ff HEATING amp COOLING Fan Coil Units Visit www carrier com Service Manual TABLE OF CONTENTS SAFETY 5 INTRODUCTION UNIT IDENTIFICATION PRODUCT OFFERING FAN MOTOR SPEED TAPS FA4A FB4A FC4B AND 4 CIRCUIT BOARD FUNCTION AND TROUBLESHOOTING CES013003 00 and 01 Printed Circuit Board PCB Component Layout and Description Unit Functions Troubleshooting PCB CIRCUIT BOARD FUNCTION AND TROUBLESHOOTING HK61GA001 AND HK61GA003 CIRCUIT 5 Printed Circuit Board PCB Component Layout and Description PCB Component Functions Troubleshooting PCB ELECTRIC HEATER FUNCTION AND 5 Description of Electric Heater Components Troubleshooting KFA and KFB Series Electric Heaters FAN COIL DESCRIPTION AND TROUBLESHOOTING Integrated Controls and Motor ICM2 PCB Layout and Description Sequence of Operation Easy Select Configuration Taps Troubleshooting PCB Troubleshooting ICM2 Condensed Version of Troubleshooting FK4B Motor and Controls Accessories FAN COIL DESCRIPTION AND TROUBLESHOOTING Integra
7. CAUTION Disconnect electrical power before removing any access panels or electrical shock may result The coil is easily cleaned when dry To check or clean coil remove coil access panel If coil is coated with dirt or lint vacuum with a soft brush attachment 43 Be careful not to bend fins If coil is coated with oil or grease it may be cleaned with mild detergent and water solution Rinse coil with clean water Be careful not to splash water on insulation or filter Check drain pan and condensate drain at same time cooling coil is checked Clean drain pan and condensate drain by removing any foreign matter from pan Check for rust and holes Flush pan and drain tube with clear water If drain is restricted clean with high pressure water If this does not work use a plumber s snake or similar probe device Repitch drain pan to promote proper drainage FA4A FB4A AND FC4B SMART HEAT CIRCUIT BOARD FUNCTION AND TROUBLESHOOTING Step 1 Componeni Layout Description and Function NOTE All voltages are AC unless otherwise specified 1 The low voltage terminal board is used to connect indoor thermostat to low 24 v side of transformer and to serve as a junction between indoor thermostat and outdoor section a R terminal is used to connect secondary side of transformer to thermostat and outdoor unit R is fused b C terminal is used to connect transformer secondary common for thermostat and outdoor unit
8. 100 09 1 022 802 5 g 101 2 veo 09 L SLL Y 5 V 401 11 810 yun 9216 9 senes ofen soyioeds v 8 2 4 esiodniniN 7 Je npoy jejuozuoH piepuelg 19 MOLAN ue4 4 ed 9 61 el 211101 681 9 5 L Table 1 Product Offering MODEL UNIT SIZE DESCRIPTION CABINET FA4ANF 018 060 Multipoise Single Piece FB4ANB 042 070 Multipoise Modular FB4ANF 018 060 Multipoise Single Piece FB4ASB 042 060 Modular FB4ASF 018 060 Single Piece FC4BNB 042 070 Multipoise Modular FC4BNF 024 060 Multipoise Single Piece FD3ANA 018 030 Horizontal Single Piece FF1A FF1BNA FF1C 018 030 Vertical Single Piece FG3ANA 024 036 048 060 Horizontal Small Commercial Single Piece FH4ANB 003 004 Multipoise Modular FH4ANF 001 004 Multipoise Single Piece FK4CNB 006 M
9. RESP 30KW 3PH SCHEMATIC DIAGRAM _ FIELD POWER WIRING DISCONNECT PER NEC SEE RATING PLATE FOR VOLTS amp HERTZ apa c 1 OND 1 1 CB FU2 9 1 7 208 240 4 Wiring Diagram IF PCB FUSE KEEPS BLOWING When low voltage fuse blows it means transformer would have blown if fuse had not been in circuit to protect it The fuse usually blows when there is a high current draw on transformer high voltage applied to low voltage circuit or a direct secondary short When there is a high current draw on transformer it is most likely because transformer has been shorted or system is trying to draw more va than transformer rating allows When fuse blows because of high voltage the system has mixed high and low voltage signals 1 Check wiring of sequencers as shown in Fig 4 Be sure transformer is not shorting out because thermostat wires are miswired A94346 2 Check wiring of sequencers as shown in Fig 4 Be sure low voltage and high voltage wiring is connected to proper sequencers Check va draw on transformer If va draw is more than va rating of transformer fuse will blow If this is the case replace transformer with one that has a higher va rating and meets system specifications IF FAN RUNS CONTINUOUSLY 1 If PCB has no low voltage power check blue an
10. c Y terminal provides input signal from thermostat signaling heat pump operation d G terminal provides input signal from thermostat signaling continuous fan operation e O terminal provides input and junction terminal for revers ing valve signal f W2D terminal provides input from outdoor unit heat pump signaling control board that heat pump is in defrost g W2T terminal provides input from thermostat signaling for supplemental or emergency heat h W3 terminal provides input from outdoor thermostat W3 and W2T are factory connected by JW1 This input is used only if an outdoor thermostat is required by local codes i Y terminal provides output from control board to energize outdoor unit heat pump contactor 2 Jumper wires JW1 and JW2 See Fig 38 a JW1 connects W2T to W3 to limit staging of electric heat with use of an outdoor thermostat See Table 11 for staging Smart Heat PCB controls staging to the extent that this feature is unnecessary unless required by local codes or regulations b Cutting JW2 sets Smart Heat PCB in efficiency mode With JW2 cut there is no loss of performance due to reduced indoor blower speed when heat pump is operating near balance point This jumper may need to be cut if selected cooling fan speed is the same as required mini mum motor LO speed tap selection With JW2 cut fan terminal LO becomes a dummy terminal 3 A fuse is used to protect low voltage transformer and PC
11. 2 E ff I ai cuti EAC PLUG a ls 124 CE BLK le eg A A95318 Fig 27 KFAIRO201ACR Relay Kit Wiring Schematic FK4C DE HUMIDIFY MODE NOTE Humidistat must open on humidity rise Latent capacities for systems using the fan coil are better than average systems If increased latent capacity is an application requirement the field wiring terminal block provides connection terminals for use of a standard humidistat The 4 fan coil will detect the humidistat contacts opening on increasing humidity and reduce its airflow to approximately 8096 of nominal cooling mode airflow This reduction will increase the system latent capacity until the humidity falls to a level which causes the humidistat to close its contacts When the contacts close airflow will return to 100 of the selected cooling airflow To activate this mode remove jumper J1 and wire in a standard humidistat See Fig 28 Carefully consult product airflow data for cooling and dehumidi fication modes THERMOSTATIC EXPANSION VALVES TXV The and 4 Fan Coils are factory equipped with a hard shutoff HSO TXV The hard shutoff TXV has no bleed port and allows no bleed through after system is shutdown No pressure equalization occurs A start capacitor and relay must be installed on sin
12. 40 0VA FAN COIL HEATER 26 3VA REMAINING VA AVAILABLE 13 7VA FAN MOTOR THERMALLY PROTEC LED FLASH CODES NO LIGHT OR FLASH STEADY LIGHT STEADY FLASH NO POWER OR BOARD FAIL D FAILU STAND BY CONDITION OR FAN ONLY DIAGNOSTIC LIGHT LOW VOLT TERM BRD EQUENCER RANSFORMER PCB TRAN TERMINALS FIELD LOW VOLTAGE PLV LEADS MARKED TERMINAL PCB JUMPER JW UNMARKED TERMINAL 1 FLASH COOL DEFROS 7 FLASHES MODE EMERGENCY HEAT Fig 39 Smart Heat Typical Wiring Diagram Motor Speed at 20kw Shown 48 A94132 49 50 51 SERVICE TRAINING Packaged Service Training programs are an excellent way to increase your knowledge of the equipment discussed in this manual including Unit Familiarization Maintenance Installation Overview Operating Sequence A large selection of product theory and skills programs is available using popular video based formats and materials All include video and or slides plus companion book Classroom Service Training plus hands on the products in our labs can mean increased confidence that really pays dividends in faster troubleshooting fewer callbacks Course descriptions and schedules are in our catalog CALL FOR FREE CATALOG 1 800 962 9212 Packaged Service Training Classroom Service Training A94328 Copyright 1997 CARRIER Corp 7310 W
13. Blower On Delay To optimize comfort there is a 30 sec blower on delay in heat pump heating mode only 2 Blower Off Delay Smart Heat control uses a 60 sec off blower delay as opposed to the standard 90 sec delay Step 3 Smart Heat Operation COOLING The Smart Heat option controls cooling mode in same manner as conventional heat pumps are controlled The fan has a 90 sec delay off on cycle down Table 11 LED Codes for Smart Heat PCB FLASH CONDITION INPUT SIGNALS 5 5 OPERATION No Light Flash Board Failure Steady Light Board Failure Stand By Condition Steady Flash 1 Operating Heat Pump Plus 2 Flashes Y and or W2T 1 Sequencer Heat Pump Plus 3 Flashes Y and or W2T 2 Sequencers Heat Pump Plus 4 Flashes Y and or W2T 3 Sequencers 5 Flashes Y O Cool Mode 6 Flashes Y W2D and or W2T Defrost Mode 7 Flashes The Smart Heat option does not control heating in conventional method The PCB energizes compressor 30 sec before indoor fan is energized This allows indoor coil to heat up eliminating cold blow on start up The electric heat is staged on to allow continuous operation of heat pump and electric resistance heat below balance point below point where heat pump cannot maintain dwelling temperature witho
14. FIELD POWER WIRING FIELD GROUND WIRING FIELD CONTROL WIRING FIELD SPLICE JUNCTION MARKED CONNECTION UNMARKED CONNECTION FAN CAPACITOR FAN RELAY HEATER INDOOR FAN MOTOR LIMIT SWITCH QUAD TERMINAL SEQUENCER TERMINAL BLOCK TRANSFORMER OPTIONAL FUSIBLE LINK WIRE SLEEVE NOTES 1 TRANSFORMER PIGTAILS BLUE 208V RED 230V INSULATE UNUSED LEAD FAN MOTOR PIGTAILS RED LOW BLACK HIGH INSULATE UNUSED LEAD FAN MOTOR THERMALLY PROTECTED SUITABLE FOR USE WITH COPPER OR COPPER CLAD ALUMINUM CONDUCTORS RATED FOR 75 C MINIMUM FOR COPPER USE 6 AWG FOR COPPER CLAD ALUMINUM USE 4 AWG 4000500784 34 Typical Wiring Diagram 41 A94376 RUBBER O RING D PISTON BODY 92219 Fig 35 Refrigerant Flow Control Device For FD3A and FG3A PISTON Step 4 Liquid Tube Strainer The refrigerant flow control device is protected on indoor coil by a wire mesh strainer If strainer becomes plugged 1 Complete items 1 and 2 under Cleaning or Replacing Refrig erant Flow Control Device section 2 Loosen flare fitting joint connecting refrigerant flow control device to coil liquid refrigerant tube 3 Remove sheet metal screw holding bracket clip in place Screw is located between coil and refrigerant flow control device 4 Pull bracket clip out 5 Remove refrigerant flow control
15. Morris St Indianapolis IN 46231 f8sm a Manufacturer reserves the right to discontinue change at time specifications designs without notice and without incurring obligations 100 3 ki PC 101 Catalog No 92 33FA 4A23 Printed in U S A Form F 3SM Pg 52 3 97 Replaces F 2SM al e
16. before each cooling season If coil inlet face is coated with dirt or lint vacuum with a soft brush attachment Be careful not to bend coil fins If coil is coated with oil or grease clean it with a mild detergent and hot water solution Rinse coil with clear water Be careful not to splash water onto insulation Inspect drain pan and condensate drain at same time cooling coil is checked Clean drain pan and condensate drain by removing any foreign matter from pan Flush pan and drain tube with clear water Clear drain line if restricted NOTE There MUST be a trap in condensate line Trap must be at least 3 in deep not higher than the bottom of unit condensate drain opening and pitched downward to an open drain or sump BLOWER MOTOR AND WHEEL Clean blower motor and wheel when cooling coil is cleaned Lubricate motor every 5 years if motor is used on intermittent operation thermostat FAN switch at AUTO position or every 2 years if motor is in continuous operation thermostat FAN switch at ON position Remove motor to lubricate Put approximately 8 drops of SAE 10 nondetergent oil in each oil hole Do not overoil motor Plug hole securely so that oil does not drip when hinged access panel is lowered to open position Blower motor and wheel may be cleaned using a vacuum with a soft brush attachment Remove grease with a mild solvent such as hot water and detergent Be careful not to disturb balance weights clips on blower wheel v
17. side of transformer to indoor thermostat and outdoor section 2 A 5 amp fuse is used to protect the low voltage transformer secondary 3 The fan relay is controlled by thermostat and turns fan on and off 4 A plug is used as the connection for PCB power and electric heaters Note the pin numbers on plug 5 A time delay relay circuit keeps fan motor running for 90 sec after G is de energized Step 2 Unit Functions TRANSFORMER 1 Proper Wiring of Transformer Primary or High Side Yellow wire from Molex plug is wired to C terminal on transformer and black wire from PCB relay normally open terminal is wired to 208V or 230V terminal on transformer Units are factory wired at 230V terminal 2 Proper Wiring of Transformer Secondary or 24 v Side Red wire of transformer is wired to T terminal on PCB and brown wire of transformer is wired to C terminal on PCB NOTE T terminal on PCB is used to protect transformer T terminal is connected through the fuse to R terminal on PCB 9 4 219 010 900 ue 4 suonisog ur uL WOI M 10H 15 9215 pJepuels H eww 9 4 ul 4 4 pese ul peunJ suo nnw 200 08 L 0 2 5 exnjeq suo
18. 3 2 61 2 COMPONENT ARRANGEMENT ko BLU AVTB 2 PLUG 2 4 9 117 f CED 9 11777 S 2 XX 2527 2 E ror og RED D 77 SYSTEM TRANSFORMER 40 0VA TRAN SEC2 FAN COIL HEATER 15 2VA RED 32 1 REMAINING VA AVAILABLE 24 8 24 46 2 208 AUXIHEAT 6 R 2 BRN 290N TFM 2 30 0 20 0 10 0 5 YEL CFM 4075 1525 1350 1050 amp 8 230 208v VIO Sr 5 H KO SEC1 SEC2 D 1 SIZE 1 o R W 060 048 042 036 2 10 10 OOO O w BLU 6 PTS Y W SYSTEM 22 GRY
19. 8 11 KW HEATERS FIELD WIRE SEE RATING PLATE IFR TDR OPTIONAL MOTOR HEAT SIZE RATING FOR VOLTS amp HZ lt 3 2 KW 14 90 3 KW 12 90 50 6 DISCONNECT fo 8 900 Bb 0 COOLING 14 90 41 BLK 2 FIELD POWER 19 SEQ LEGEND SUPPLY BLK 4 gt MARKED TERMINAL CHASSIS SEQ O UNMARKED TERMINAL GROUND 15 LIMIT SWITCH RED BLU FR FAN RELAY gr RED TRANS 25555 BRN IFR INDOOR FAN RELAY wr vio 6 E96 IFR TD INDOOR FAN RELAY TIME DELAY BRN SEQ SEQUENCER BRN ROUND CAP CAPACITOR D gt hd e R CHASSIS De GROUND TRANS TRANSFORMER RC 5 Vides es FIELD POWER WIRING OPTIONAL IFR TDR w e e e OPTIONAL WIRING SCHEMATIC DIAGRAM FOR COOLING CONTROL FUSE BLK CHASSIS GROUND SEE RATING PLATE IFR TDR OPTIONAL MOTOR CAP FOR VOLTS amp HZ 354 8 5 BRN DISCONNECT 4 RED 22 5 77 FIELD ol SUPPLY Vio CHASSIS BLU BLK GROUND BRN R RED TRANS om demo G BRN BRN BRN CHASSIS GROUND R L e G e ORN jan CHASSIS ea BRN GROUND OPTIONAL IFR TDR 1 UNIT WIRED FOR 230V OPERATION USING BLACK AND RED TRANSFORMER PRIMARY LEADS FOR 208V OPERATION USE BLACK AND BLUE TRANSFORMER PRIMARY LEADS 2 U
20. BLU HP COMFORT HP EFF 6 lt 0 11 2 ORN i CFM ADJUST lt RED y NOM LO HI E 7h 4 BLK O 6 2 KD 1 9 6 ON OFF DELAY Q rs WHT 30 0 HI 90 90 0 N PLUG WHT 1010 BK BLK CONTINUOUS FAN AUX1 HUM1 2 PL1 2 MED 25 AUX2 HUM2 GND ICM PLUG 1 1 24 NOTES HEATER MOTOR 1 USE COPPER WIRE 75 C MIN ONLY BETWEEN DISCONNECT Ek SWITCH AND UNIT o 3 2 TO BE WIRED ACCORDANCE WITH NEC LOCAL CODES 22 gt 3 TRANSFORMER PRIMARY LEADS BLUE 208V RED 230V gt 4 IF OF THE ORIGINAL WIRE AS SUPPLIED MUST NE 54 ICM REPLACED USE THE SAME OR EQUIVALENT TYPE WIRE 27 20 _ 5 REPLACE LOW VOLTAGE FUSE WITH NO GREATER THAN 5 AMP FUSE DE 2 6 20KW HEATER USES ONE DOUBLE POLE LS ON MIDDLE ELEMENT 7 18 24 AND 30KW HEATERS USE DOUBLE POLE LIMIT SWITCHES E l GRY 8 LARGEST HEATERS ARE SHOWN SMALLER HEATERS WILL HAVE FEWER ELEMENTS AND COMPONENTS 9 1 PHASE HEATERS ARE SHOWN WIRED FOR SINGLE SUPPLY CIRCUIT 10 USE 60 AMP CLASS K FUSES ONLY FOR REPLACEMENT 11 CONNECT R TO
21. EAC2 and neutral of 230 v 120 v transformer 56 gFus p gt ojruep YEL BLK BLK XEE 25 8 QFU4 D YEL 55 HTR5 BLK SEQ BLK 5 BLK druzp LOW VOLTAGE TERMINAL BOARD BLK BLU Q Q BLK W3 L e 2122 INDOOR O THERMOSTAT Y 2 1 8 G 1 1 C ETC C C LU gt lt VIO 9 lt ORG G SEQ3 SEQ2 3 D AUXI BRN RED BRN 6 4 24VDC YEL 9 7 AU BLK 11 5 20 TRANSFORMER BP AC LINE DUMMY 1 1 1 1 F2 T1 T2 T3 L2 EAC2 DUMMY COMMON DUMMY FAN RED LO T CAP 240 VAC 240 VAC O O YEL COM BLU GRN YEL GND BLK 208V COMM 230V TRAN BRN 24V RED 24V A97027 Fig 7 10kw to 20kw Circuits 10 connected to EAC 2 Refer to electronic air cleaner literature for further information 2 AUX1 and AUX2 for 2 Speed Fan Relay Kit a Use to control fan speed
22. PCB 1 Check the plug receptacle connection this brings power to the PCB Make sure the plug is connected properly 2 Check sequencer number 1 and the plug s wiring the yellow wire should be connected to pin number 9 of the plug and the limit switch black wire should be connected to pin number 7 of the plug and to sequencer number 1 3 Check power leads L1 and L2 If these are not receiving power the system cannot function If the PCB has high voltage applied to it 1 Check the low voltage transformer leads R and C Make sure they are wired to the correct locations Note that Fig 12 shows wiring of the HK61GA001 board 2 Check the output voltage of the secondary side R and C of the transformer If the circuit board is a HK61GA003 make sure the ground strap is in place from C to the bracket This strap must be in place to complete the 24 v circuit Make sure the transformer output is around 24 v ac If the transformer output is zero v ac and the transformer is receiving the correct input voltage 208 v or 240 v then the transformer needs to be replaced with the recommended transformer If the trans former output is 24 v ac then proceed to 3 and 4 3 Check the low voltage fuse shown in Fig 5 and Fig 6 If the fuse is blown replace it The transformer cannot supply power to the board with the fuse blown or loose If the fuse blows when the unit has power applied to it the system most likely has 1 of the following p
23. R G TO G ETC SEE OUTDOOR INSTRUCTIONS 322857 101 96432 25 Wiring Diagram 31 Table 9 Motor Control Test Values VOLTAGES 12 PIN PLUG PL1 OPERATING MODE Wi R vi 7 1 9 10 8 2 3 Electric Heating R W1 W2 24 vac 0 0 0 24 vac 0 1 Speed A C Cooling R Y Y2 G 0 24 vac 0 0 24 vac 24 vac 0 2 Speed Low Speed Cooling Y1 G 0 24 vac 0 0 24 vac 0 24 vac 2 Speed A C High Speed Cooling R Y Y2 G Y1 0 24 vac 0 0 24 vac 24 24 vac 1 Speed HP Cooling R Y Y2 G 0 24 0 0 24 24 0 1 Speed HP Heating Y Y2 0 24 0 0 24 24 vac 0 2 Speed Low Speed Cooling R Y1 G 0 24 0 0 24 0 24 2 Speed HP Low Speed Heating Y1 G 0 24 vac 0 0 24 vac 0 24 vac 2 Speed HP High Speed Cooling R Y Y2 Y1 0 24 0 0 24 vac 24 vac 24 vac 2 Speed High Speed Heating 2 Y1 0 24 vac 0 0 24 24 24 Continuous Fan R G 0 24 vac 0 0 24 vac 0 0 2 Check power leads L1 and L2 If these are not receiving power system cannot function If Motor Has High Voltage Applied To It 1 Check low voltage transformer leads red and brown Be sure they are wired to correct locations See Fig 23 and 25 2 Check low voltage fuse shown
24. R MOTOR 59 7 JUMPER GROUND 2ND STAGE SCREW n NB REQUIRED ps 8 ET PU 00 2AVAC E L MALE 346 IN MALE ma E ug eb FASTON Rese 3053 21 PLCS ae 1 4 na CES0130007 00 9 12 MATE N LOCK 1 94076 Fig 15 Easy Select Board Step 3 Sequence of Operation CONTINUOUS FAN MODE The thermostat closes circuit R to G The G signal is sent directly to ICM2 COOLING MODE SINGLE SPEED OR 2 SPEED HIGH Thermostat closes circuits R to Y Y2 and R to O heat pump only for single speed A circuit from to is also required for 2 speed high The Y Y2 signal is sent directly to ICM2 COOLING MODE TWO SPEED LOW Thermostat closes circuits R to Y1 and R to O heat pump only The Y1 signal is sent directly to ICM2 ELECTRIC HEAT HEATING MODE Thermostat closes circuit R to W2 W3 or E The terminal block positions W2 W3 and E are tied together by jumpers JW1 and JW2 These jumpers are provided for field staging of electric heater banks through use of thermostats When staging is a requirement installer cuts jumpers and wires in thermostats as is the common practice with other fan coils To ensure motor operation if any 1 of the inputs is energized the 3 electric heater inputs are also interlocked thro
25. Terminals T1 T2 if used and T3 are wired to primary 5 When both W3 and W2T are energized without JW1 being cut or high side of transformer The 208 v terminal or blue wire if or with outdoor thermostat closed system operation stages transformer has primary leads is used on for 208 applica heat up to maximum level if signal is energized for proper tions The 230 v terminal or red wire is used on T3 for 230 v amount of time applications T2 is a dummy terminal 6 If only W3 is energized there is no effect on PCB No heat is ELECTRIC HEAT NOTE When troubleshooting elements position thermostat to ACCESSORIES emergency heat Wait approximately 12 minutes for all elements to come on 1 When thermostat calls for electric heat a 24 v signal is sent to PCB through W2T The PCB energizes first stage of electric heat 2 The first 2 stages come on if W2T and Y are energized at the same time After each 10 minutes W2T is energized another stage of electric heat is energized 3 As W2T is de energized electric heat stages down in 8 minute steps with the exception of first step The first step will be on only half as long as it was prior to W2T de energizing 44 Terminals AUX and AUX are energized with 24 when fan is energized The accessory kit 101 is used to connect an EAC or humidifier NOTE Loads cannot be connected directly to AUX and AUX Use the specified kit only BLOWER 1
26. Y is de energized 5 O is used as a junction for a heat pump reversing valve circuit 6 W2 is used to turn on the first stage of electric heat which is interlocked with the fan through the normally closed fan relay Unless the tabs are broken off all stages of electric heat will turn on when W2 receives a signal from the thermostat 7 W3 is used to turn on the second stage of electric heat Note the W2 and W3 tab must be broken off for individual staging to take place Energizing W3 will always turn on the first stage through the diodes even if the tabs are broken off 8 E is used to turn on the third stage of electric heat Note that the W3 and E tab must be broken for this individual staging Energizing E will always turn on the first stage through the diodes even if the tab is broken off 9 L is used as a junction to wire a diagnostic light LED on selected thermostats TRANSFORMER The proper wiring of the transformer on the HK61GA001 board is illustrated in Fig 7 Note that T1 T2 and T3 are wired to the primary or high side of the transformer The blue wire is connected to T3 for 208 v applications The red wire is connected to T3 for 230 v applications Units are factory wired at 230v The T2 terminal is a dummy INDOOR FAN 1 Wiring The fan connects to F1 F2 F3 and F4 as shown in Fig 7 Note that F2 and F3 are dummy terminals The desired fan speed is connected to F4 and the common is connected to F1 Units ar
27. blow If this is the case replace the transformer with 1 that has a higher va rating and meets system specifications THE FAN RUNS CONTINUOUSLY 1 If the PCB has no low voltage power check the blue and black fan leads These may be switched at the sequencer 2 If the PCB has low voltage power check the fan relay to see if it is opening and closing It may be stuck in the normally closed position due to debris in the relay 3 See Service Manager Bulletin SMB 92 3 TRANSFORMER FAILURE 17 1 Check 208 v and 240 v taps connected to and T3 They may be miswired ELECTRIC HEATER FUNCTION AND TROUBLESHOOTING This section describes KFA and KFB series electric heaters in exclusion of Smart Heat by examining the functional operation of these heaters Step 1 Description of Electric Heater Components LIMIT SWITCH The limit switch is a temperature sensitive control whose function is to prevent system from overheating in abnormal conditions The temperature settings often vary from heater to heater due to variations in airflow patterns and element radiant heat conditions The devices are sized to remain on line under heat pump condi tions 115 F air off coil and minimum CFM but trip to prevent outlet air conditions above 200 F or excessive component or duct temperatures The device itself consists of a bimetallic disc which when overheated snaps through to open a normally closed high voltage high cu
28. common practice with other fan coils To ensure motor operation if any 1 of the inputs is energized motor will sense input W1 or W2 and run HEAT PUMP HEATING MODE SINGLE SPEED OR 2 SPEED HIGH Thermostat closes circuit R to Y Y2 for single speed A circuit from R to is also required for 2 speed high The Y Y2 amp Y1 signal is sent to ICM2 HEAT PUMP HEATING MODE TWO SPEED LOW Thermostat closes to Y1 The 1 signal is sent to ICM2 28 HEAT PUMP HEATING WITH AUXILIARY ELECTRIC HEAT Thermostat closes circuits R to Y Y2 and or to Y1 with to W1 or W2 and R to O in the case of defrost The terminal block positions W1 and W2 are tied together by jumper J2 is provided for field staging of electric heater banks through use of thermostats When staging is a requirement remove J2 jumper and wire in thermostats as is the common practice with other fan coils To ensure motor operation if any 1 of the inputs is energized motor will sense input W1 or W2 and run In the event that electric heating is called for by thermostat while heat pump is also operating in either heating or defrost mode electric heating signal will appear at motor connector pins 6 and 7 W1 and or pins 4 and 5 W2 as described previously If necessary the motor will modify its airflow output to provide an airflow which is defined as safe for operation of electric heater SYSTEM DIAGRAM HEATER MOTOR Siena
29. heat pump heating modes 10 percent and 10 percent respec tively The adjust selection options are provided to adjust airflow supplied to meet individual installation needs for such things as noise comfort and humidity removal See Fig 15 AC HP TIME DELAY Select desired time delay profile Four motor operation delay profiles are provided to customize and enhance system operation See Fig 15 The selection options are 1 The standard 90 sec off delay factory setting 2 No delay option used for servicing unit or when a thermostat is utilized to perform delay functions 3 A 30 sec on 90 sec off delay profile used when it is desirable to allow system coils time to heat up cool down prior to airflow This profile will minimize cold blow in heat pump operation and could enhance system efficiency 4 ENH enhanced selection provides a 30 sec on 180 sec off delay at half airflow adding comfort and efficiency Step 5 Troubleshooting PCB Use Fig 16 and 17 and Tables 3 4 and 5 as guides in troubleshooting PCB unless otherwise noted IF FAN WILL NOT TURN ON FROM THERMOSTAT If There Is No High Voltage To PCB 1 Check connection of 12 pin plug from heaters to receptacle on Easy Select board This supplies power to PCB Be sure plug is connected properly 2 Check sequencer number 1 and plug wiring Yellow wire should be connected to pin number 9 of plug and to limit switch Black wire should be connected to pin numb
30. is depicted in Fig 23 and 24 The PCB interfaces a variable speed ICM2 with other system components Power for system is supplied from a 230 vac 60 Hz line Class 2 voltage 24 vac nom used for thermostat connections is derived from transformer located in close proximity to PCB The primary and secondary of transformer are connected to PCB The 24 vac secondary circuit includes 5 amp automotive type fuse in SEC2 circuit Connection to heater panel is made through 12 circuit connector Connections to thermostat are made at screw terminals Twenty one pin terminals comprise field select taps for motor Fuse Data 5 amp automotive type ATC ATO tan 32v 200 percent current opening time of 5 sec maximum 27 ELECTRICAL CONNECTIONS Twenty one 0 110 in pin terminals are used to provide program ming selections for operating modes 2 The 6 selection modes are listed below For additional information refer to Easy Select Configuration Taps section AUX Heat Range Violet Wire Size Blue Wire Type Orange Wire AC HP CFM Adjust Black Wire AC HP Time Delay Grey Wire Continous Fan Yellow Wire Step 11 Sequence of Operation CONTINUOUS FAN MODE The thermostat closes circuit R to G The G signal is sent directly to ICM2 COOLING MODE SINGLE SPEED OR 2 SPEED HIGH Thermostat closes circuits R to Y Y2 and R to O heat pump only for single speed A circuit from R to Y1 is also require
31. make sure sensing bulb is in good thermal contact with suction tube PISTON BODY CLEANING OR REPLACEMENT CAUTION Do not vent refrigerant to atmosphere Recover during system repair or final unit disposal CAUTION Damage may occur to the scroll compressor if operated at a negative suction pressure during a system pumpdown 1 Pump down outdoor unit Close service valves at outdoor unit 2 Recover remaining refrigerant from tubing and coil through gage port on vapor tube service valve 3 Disconnect refrigerant liquid tube from piston body See Fig 29 4 Avoid damaging seal ring or machined surfaces on piston bore and retainer 5 Using small wire with a hook on end of it remove piston from body TEFLON SEAL PISTON 2 0 201 F PISTON BRASS RETAINER BODY BRASS HEX NUT A93530 Fig 29 Refrigerant Flow Control Device For FA FB and FF CAUTION When cleaning the piston orifice be careful not to scratch or enlarge the opening as this will affect operation Install new or cleaned piston into body 6 7 Replace seal ring on retainer 8 Reconnect refrigerant tube to piston body 9 Pressurize tubing and coil then leak check 10 Evacuate tubing and coil as necessary CAUTION Use backup wrench do not over tighten as deformation of the piston body will occur causing the piston to lodge in a par
32. of it remove piston from refrigerant flow control device body CAUTION When cleaning piston orifice be careful not to scratch enlarge opening as this will affect operation A CAUTION Use a backup wrench and do not overtighten as deformation of refrigerant flow control device body will occur causing piston to lodge in a partially open or closed position 6 Install new or cleaned piston in refrigerant flow control device body 7 Install new retainer because of probable damage which occurred in initial removal 8 Reconnect refrigerant tube to refrigerant flow control device 9 Pressurize tubing and coil then leak check 10 Evacuate tubing and coil as necessary 00zmir d 5 2 2 SEQ 3 SCHEMATIC DIAGRAM Zo FR 3 SEQ SEQ TB42 BLK ans lt 1 FL 1 K2 Be 82 BLK O O LO REY 2 2 18 2 18 2 1 BLU wy ORN BRN ORN BRN COMPONENT ARRANGEMENT BLK 2 FIELD POWER WIRING HTR2 94 OPTIONAL YEL 1 SN SEF NOTE 4 1 Be EQUIP GND BDA mos DISCONNECT A d00zumid LEGEND
33. original terminals 9 Replace blower access door and tighten all 4 screws 10 Reinsert disconnect pullout only after blower access door is secured Test blower for proper operation BLOWER WHEEL INLET RING GROMMET MOTOR 86006 Fig 33 FF1A FF1B FF1C Motor Inlet Ring Blower Wheel Assembly FD3A SERVICE AND TROUBLESHOOTING A WARNING Before installation or servicing system always turn off main power to system There may be more than 1 disconnect switch Turn off accessory heater power if applicable Elec trical shock can cause personal injury or death Step 1 Fan Motor The motor is 2 speed direct drive High speed lead is black low speed lead is red and common lead is yellow NOTE Unused fan speed leads must be tapped off to prevent direct short to cabinet surface The motor is turned on through 2 different routes The first occurs when thermostat calls for the fan in cooling heat pump or fan only mode A 24 vac signal is sent to relay causing relay to close its normally open contacts turning fan on The second occurs when there is a call for electric heat A 24 vac signal is sent to heater sequencer causing it to close directing 230v through the normally closed contact of fan relay turning fan on The fan remains on until sequencer opens Refer to FD3A typical wiring d
34. sequencer opens Refer to FFIA FFIB FFIC typical wiring diagram See Fig 32 If motor does run test motor for an open winding or a winding shorted to motor case If any 1 of the 2 is present replace motor Step 2 Electric Heater Service Service can be completed with heater in place Shut off power before servicing LIMIT SWITCH Malfunction prevents heating element from coming on Replace switch if malfunction occurs SEQUENCER Malfunction causes heater not to come on or never shut off Replace sequencer TRANSFORMER A 40 va transformer supplies 24 v power for control circuit Replace transformer if faulty NOTE Transformer is fused Do not short circuit FAN RELAY Malfunction causes unit fan not to run or run continuously Replace relay Step 3 Cleaning or Replacing Refrigerant Flow Control Device Refer to Fig 29 and instructions given in Piston Body Cleaning or Replacement section above Step 4 Liquid Tube Strainer The refrigerant flow control device is protected by a wire mesh strainer It is located inside the 3 8 in liquid tube at field braze joint next to flow control device Access to strainer is through field braze joint Step 5 Sequence of Operation Refer to Fig 32 CONDENSING UNIT Cooling When thermostat calls for cooling the circuit between R and G is complete and single pole single throw relay FR is energized The normally open contacts close causing blower to operate The
35. straight electric heat the fan is also energized through the normally closed contacts of the fan relay In cooling heat pump or manual fan mode the fan will already be running since the fan relay would have been energized When the thermostat stops calling for electric heat the 24 v dc signal to sequencer number 1 turns off and the sequencer opens after a delay of 60 to 90 sec When the sequencer opens the first stage of heat turns off along with the fan providing that the thermostat is not calling HK61GA001 HK61GA001A LOW VOLTAGE TERMINAL BOARD 2ND STAGE ELECTRIC HEAT BREAKOFF TABS FOR STAGING STAGE INTERLOCK C PLUG t 67 NOT USED FUSE LOW VOLTAGE CONNECTIONS FOR VARIOUS ACCESSORIES TRANSFORMER CONNECTIONS T1 T2 COMMON DUMMY 2 DUMMY Fe FAN 2 FAN CONNECTIONS EAC1 COMMON J 240 VAC X ELECTRONIC AIR CLEANER CONNECTIONS A97025 Fig 5 HK61GA001 Printed Circuit Board for the fan Note that the electric heat cannot be turned on without the fan being turned on at the same time This is a fan interlock system 2 W3 When a signal is sent to W3 2 control signals are sent out to the sequencers a 24 v dc signal to se
36. supply circuits may be wired directly to fuse C B S HVTB HIGH VOLTAGE TERMINAL BOX HUM HUMIDIFIER 17 Wiring Diagram 24 A94078 Table 6 Control Test Values VOLTAGES 7 PIN PLUG P2 OPERATING MODE SING VR W R Y Pin 1 Pin 2 3 Pin4 5 6 7 Electric Heating R W2 W3 E 24 vde 0 0 0 24 vac 0 1 Speed A C Cooling Y Y2 0 24 0 0 24 24 vac 0 2 Speed Low Speed Cooling Y1 G 0 24 vac 0 0 24 vac 0 24 vac 2 Speed A C High Speed Cooling Y Y2 G 0 24 vac 0 0 24 vac 24 vac 0 1 Speed HP Cooling Y Y2 0 24 0 0 24 24 0 1 Speed Heating 2 0 24 0 0 24 24 0 2 5 Low Speed Cooling 1 0 24 0 0 24 0 24 2 5 HP Low Speed Heating R Y1 G 0 24 vac 0 0 24 vac 0 24 vac 2 Speed HP High Speed Cooling Y Y2 Y1 0 24 0 0 24 24 24 2 Speed High Speed Heating 2 1 0 24 0 0 24 24 24 Continuous Fan R G 0 24 vac 0 0 24 vac 0 0 Pin 1 24 with or without jumpers when ever any individual heater inpu 2 Verify that there are approximately 230v at terminals M1 and M2 If not determine if high voltage is entering board It enters through black and yellow
37. AT 1 Check fuse for failure If fuse has failed refer to Fuse Failure section 2 Check for faulty transformer Check output voltage of trans former secondary side R red and C brown Make sure output is between 18 and 30 vac If output voltage is low and input voltage tests normal replace transformer 3 Check for miswired heater plug harness 4 Check limit switch or sequencer failure These switches should have failed in open position If output voltage is zero v replace switch HEATER WILL NOT TURN OFF 1 Check low voltage wiring for miswire 2 Check for shorted elements to ground 3 Replace sequencer contacts They may be stuck closed NUISANCE TRIPS 1 Check for low airflow due to dirty filters blocked registers or undersized duct 2 Check blower motor and wheel for proper operation Exces sive current draw of motor will cause internal overload to trip 3 The fan speed may be low FAN COIL DESCRIPTION AND TROUBLESHOOTING FK4B The FK4B is similar to the discontinued FK4A only in that they both have integrated controls and motor ICM and their own special circuit board The greatest difference between the 2 models is the way each goes about delivering air Setting up desired airflow on the FK4B is obtained by the selections made on Easy Select circuit board The motor delivers requested airflow as defined by signals received from Easy Select Board and its internal programming The major difference is th
38. B 4 AUX and AUX are connections for air conditioning acces sories EAC humidifier etc 5 F1 F2 and LO are connections for indoor fan 6 The 9 pin receptacle connects heater package wiring harness 7 SEC1 and SEC2 are used to connect secondary side of transformer to PCB SECI is connected to equipment ground CEPL130121 01 MOV1 LOW VOLTAGE TERMINAL BOARD CESS430121 01A CUT WHEN OUTDOOR THERMOSTAT IS USED HIGH FAN ONLY WHEN XFORM RECEPTACLE LIP JUMPER FOR DUMMY 240 HIGH SPEND FAN ONLY CES0130025 4 94127 38 5 Table 10 Electric Heater Stage Limiting STAGES KW OPERATING HEATER PART NO W2T Only JW1 cut W3 1 2 3 4 KFAEH2201H10 10 kw Non Fused 3 6 9 9 KFAEH2301H15 15 kw Fused 3 8 11 15 KFAEH2401H20 20 kw Fused 5 10 15 20 Step 2 Unit Functions 4 When W2T is energized by itself JW1 is cut and an outdoor thermostat is used and is open staging is limited as in Table TRANSFORMER 11 NOTE
39. ERMINAL MOTOR MARKED RED HUMIDISTAT WIRING FOR DE HUMIDIFY MODE A93215 Fig 21 Humidistat Wiring for De Humidify Mode FK4C The is similar to the discontinued FK4B only in that they both have integrated controls and motor ICM and their own special circuit board Set up of desired airflow on the FK4C is obtained by the selections made on Easy Select circuit board The motor delivers requested airflow as defined by signals received from Easy Select Board and its internal programming Unlike fan coils using induction motors where static pressure affects airflow the FK4C is a constant airflow unit The blower delivers requested airflow regardless of static pressure Consult FK4C Product Data for static pressure limits The ICM2 is pre programmed and contains airflow tables for all modes of operation Blower characteristics requested airflow torque and speed are known from laboratory testing If any 2 characteristics are known the third is defined Requested airflow is known from Easy Select board configuration and thermostat signals Torque is known because it is directly related to stator current which is measured by motor control Speed is measured by counting back EMF pulses from stator windings This information is entered into an expression which calculates torque from speed and airflow numbers If calculation does not match stored blower characteristics torque is adjusted until agreement is reached This calc
40. GING 2 E CIRCUIT FUSE LA LOW VOLTAGE Sox PLUG 242 2 9 6 3 00 6 0 EE HK61GA003 2090 WB PANDO ACCESSORIES AUX2 2 F4 FAN CONNECTIONS TRANSFORMER CONNECTIONS a NE F2 Ti T2 T3 L2 EAC2 DUMMY FAN COMMON DUMMY TRANSFORMER L1 EAC1 COMMON AC LINE 240 VAC 240 VAG X ELECTRONIC AIR CLEANER CONNECTIONS A97026 Fig 6 HK61GA003 Printed Circuit Board electric heat The 24 v dc signal applied to sequencer 1 turns on the first stage of electric heat and the fan in the same manner as W3 Note that E is also interlocked with the fan When the thermostat stops calling for electric heat the signals to sequencers 1 and 3 are turned off and the sequencers open This causes the electric heat to turn off with the fan if the thermostat is not calling for the fan ACCESSORIES 1 EACI and 2 for Electronic Air Cleaners a There are 240 v electronic air cleaner contacts provided at EACI and 2 The electronic air cleaner is connected in parallel with the fan so that it is on whenever the fan is on A 120 v installation is similar in function but connected between
41. IF MOTOR DOES NOT STOP RUNNING 1 Check for good ground between motor ground lead and transformer common lead 2 If motor continues to run remove all thermostat wires If motor stops check thermostat wiring to thermostat or outdoor unit for shorts or miswire Step 15 Condensed Version of Troubleshooting FK4C Motor and Controls This section provides a quick summary of how to troubleshoot the If more information is needed refer to appropriate sections of this service manual MOTOR motor is hard to turn manually replace motor motor does not run check the components listed below according to their instructions motor runs in some operation modes and not in others check for a good ground connection between motor ground lead and circuit board screw marked ground screw and check the room thermostat and wiring harness according to instructions listed below CIRCUIT BOARD Check 5 amp fuse Check for 24v between 5 1 and SEC2 If no voltage is present check the transformer Check for burn traces or burnt components If burn spots are present replace board ROOM THERMOSTAT Remove thermostat wires from the circuit board Jumper screw terminals 1 at a time R Y Y2 R Y1 and R W1 If motor runs in all cases thermostat is bad Replace thermostat If motor does not run or runs in some cases but not in others continue by checking the wiring harness WIRING HARNESS
42. ION These words are used with the safety alert symbol DAN GER identifies the most serious hazards which will result in severe personal injury or death WARNING signifies hazards which could result in personal injury or death CAUTION is used to identify unsafe practices which would result in minor personal injury or product and property damage INTRODUCTION The F series fan coil units are designed for flexibility in a variety of applications meeting upflow horizontal or downflow require ments Units are available in 1 1 2 through 5 ton nominal cooling capacities Factory authorized field installed electric heater pack ages are available in 3 through 30 kilowatts A WARNING Before installing or servicing fan coil always turn off all power to unit There may be more than 1 disconnect switch Turn off accessory heater power if applicable Electrical shock can cause personal injury or death UNIT IDENTIFICATION The 16 position numbering chart allows identification of all available fan coil units See Fig 2 FA4A FB4A FC4B AND FH4A CIRCUIT BOARD FUNCTION AND TROUBLESHOOTING CES0130003 00 and 01 PCB This section of the service manual describes the CESO130003 00 and 01 PCB by examining the functional operation of the PCB components Step 1 Printed Circuit Board PCB Component Layout and Description Layout of the actual PCB is depicted in Fig 3 1 The low voltage stripped leads are used to connect the 24 v
43. If sequencer is closing check high voltage wiring as discussed in items 1 and 2 If Traces Are Overheated on Back of PCB Usually whenever there is a trace blown on PCB it means either there has been a high voltage short or high voltage has been applied to low voltage circuit This can be prevented by making sure PCB is wired correctly before fan coil has power applied to it IF PCB FUSE KEEPS BLOWING When low voltage fuse blows it means transformer would have blown if fuse had not been in circuit to protect it The fuse usually 32 blows when there is a high current drawn on transformer high voltage applied to low voltage circuit or a direct secondary short When there is a high current drawn on transformer it is most likely because transformer has been shorted or system is trying to draw more va than transformer rating allows When fuse blows because of high voltage the system has mixed high and low voltage signals 1 Check transformer and thermostat wiring See Fig 23 and 25 Be sure transformer is not shorting out because thermostat wires are miswired 2 Check wiring of sequencers See Fig 23 and 25 Be sure low voltage and high voltage wiring are connected to proper sequencers 3 Check va draw on transformer If va draw is more than va rating of transformer fuse will blow If this is the case replace transformer with one that has a higher va rating Step 14 Troubleshooting ICM2 Fan
44. Motor IF MOTOR DOES NOT RUN 1 With power turned off check all plugs and receptacles on circuit board and at motor for any deformation that may cause a bad connection Be sure all plugs are placed fully seated 2 Verify that there is approximately 230v 3 Verify that there is a low voltage control signal to motor The motor receives its control signals through the 12 pin motor plug PL1 The voltage output of each pin in plug will be different for each mode of operation Table 6 lists circuit board screw terminals that have 24 vac present powered by thermostat and lists voltage that is present at each pin of 12 pin plug for each operating mode Tests should be taken between points listed and common C screw terminal If all values of any 1 of operating modes checks OK and motor fails to run then motor is defective and should be replaced IF MOTOR DOES NOT RUN SMOOTHLY First verify that the cause is not an out of balance or damaged blower wheel If it is not blower wheel motor is defective and should be replaced IF MOTOR SHAFT DOES NOT ROTATE SMOOTHLY When manually turning shaft of ICM the shaft does not rotate smoothly The shaft has steps during rotation and is referred to as motor cogging The cogging is caused by permanent magnets passing each pole of motor However shaft should not require excessive force to turn If shaft is VERY difficult to turn motor control or bearings have failed and motor must be replaced
45. NUSED TRANSFORMER LEADS MUST BE TAPED AND LOOPED 3 IF ANY OF THE ORIGINAL WIRE AS SUPPLIED MUST BE REPLACED USE THE SAME OR EQUIVALENT WIRE 4 FIELD WIRING USE COPPER CONDUCTORS ONLY 5 FAN RELAY 4 18 A DEAD TERMINAL FOR UNUSED MOTOR LEAD STORAGE TO CHANGE MOTOR SPEEDS EXCHANGE THE BLACK AND RED MOTOR LEADS ON THE FAN RELAY 316596 401 REV B Fig 32 FF1A FF1B FF1C Typical Unit Wiring Label 38 A91140 Cooling On a call for cooling the thermostat makes circuits R O R Y and R G Circuit R O energizes reversing valve switching it to cooling position Circuit R Y energizes contactor starting outdoor fan motor and compressor Circuit R G energizes indoor unit blower relay starting indoor blower motor When thermostat is satisfied its contacts open de energizing contactor reversing valve and blower relay This stops compressor and fan motors Heating On a call for heating the thermostat makes circuits R Y and R G Circuit R Y energizes contactor starting outdoor fan motor and compressor Circuit R G energizes indoor blower relay starting blower motor Should temperature continue to fall R W circuit is made through second stage room thermostat bulb Circuit R W energizes a sequencer bringing on supplemental electric heat When thermostat is satisfied its contacts open de energizing contactor and sequencer All heaters and motors should stop Step 6 Care and Maintenance The min
46. Operating Sequences and Troubleshooting Manufacturer reserves the right to discontinue or change at any time specifications or designs without notice and without incurring obligations 114 34 2 101 Catalog 92 33FA 4A23 Printed in U S A Form F 3SM Pg 1 3 97 Replaces F 2SM SAFETY CONSIDERATIONS Improper installation adjustment alteration service maintenance or use can cause explosion fire electrical shock or other conditions which may cause personal injury or property damage Consult a qualified installer service agency or your distributor or branch for information or assistance The qualified installer or agency must use factory authorized kits or accessories when modifying this product Refer to the individual installation instruc tions packaged with the kits or accessories for detailed informa tion Follow all safety codes Wear safety glasses and work gloves Use quenching cloth for brazing operations Have fire extinguisher available Read these instructions thoroughly and follow all warnings or cautions attached to the unit Consult local building codes and National Electrical Code NEC for special installation requirements It is important to recognize safety information This is the safety alert symbol When you see this symbol on the unit or in instructions and manuals be alert to the potential for personal injury Understand the signal words DANGER WARNING and CAU T
47. R FIELD POWER WIRING COOLING CONTROL ONLY WIRING YEL BLK 11 PLUG 9 6 1 4 4 208 240 24 24 9 11 7 3 2 61 4 BARRIER SEE WHT SEE NOTE 1 3 12 GRN YEL GND 5 UNIT f DOOR OUTDOOR USE COPPER WIRE 75 C MIN ONLY BETWEEN O BE WIRED IN ACCORDANCE WITH NEC AND LOCAL CODES RANSFORMER PRIMARY LEADS BLUE 208V RED 230V F ANY OF THE ORIGINAL WIRE AS SUPPLIED MUST BE REPLACED USE THE SAME OR EQUIVALENT TYPE WIRE REPLACE LOW VOLTAGE FUSE WITH NO GREA 20KW HEATER USES ONE DOUBLE POLE LS ON MIDDLE TOP ELEMENT 8 24 AND 30KW HEATERS USE DOUBLE POLE LIMIT SWITCHES LARGEST HEATERS ARE SHOWN SMALLER HEATERS WILL HAVE FEWER ELEMENTS AND COMPONENTS PHASE HEATERS ARE SHOWN WIRED FOR SINGLE SUPPLY CIRCUIT USE 60 AMP CLASS K FUSES ONLY FOR REPLACEMENT 8 SPEED MOTOR SHOWN OPTIONAL 2 SPEED MOTOR USES BLK AND LOW BLU OR RED CONNECT TOR ETC SEE OUTDOOR INSTRUCTION FOR DETAILS F WIRE CRIMP IS REMOVED AN EMERGENCY HEAT RELAY IS REQUIRED SEE OUTDOOR THERMOSTAT INSTRUCTIONS DISCONNECT SWITCH AND UNIT Pons ER THAN 5 AMP FUSE 321214 101
48. S amp HERTZ SEE NOTE 1 Lown 240 DUMMY 240 VAC 2 DISCONNECT SWITCH AND UNIT 4 5 OF THE ORIGINAL WIRE AS SUPPLIE NSTALLATION MINIMUM MOTOR LO SPEED TA FAN COIL SIZE 030 033 1036 5 TRAN SEE NOTE 3 YEL COM BRN NOTES GRN YEL GND USE COPPER WIRE 75 C MIN ONLY BETWEEN 2 CONNECT LOW VOLTAGE WIRING AS SHOWN 24VAC 3 CONNECT TRANSFORMER PRIMARY TO THE PROPER VOLTAGE TERMINAL O BE WIRED IN ACCORDANCE WITH NEC AND LOCAL CODES D MUST BE REPLACED USE THE SAME OR EQUIVALENT TYPE WIRE 6 REPLACE LOW VOLTAGE FUSE WITH 5 AMP FUSE 7 REFER TO THERMOSTAT INSTRUCTIONS FO EATER THAN R JUMPER 8 DO NOT CONNECT THERMOSTAT W3 P SELECTION 038 042 048 060 070 MOTOR SPEED 20 LO LO Lo LO LO LO BLK LED LVTB SEQ TRAN XFORM INDOOR THERMOSTA SEE NOTES 2 7 8 LEGEND CAP CAPACITOR COMM COMMON F LOW VOLT FUSE FW MOTOR GND EQUIPMENT GROUND HPLV HEAT PUMP LOW VOLT HEATER LS LIMIT SWITCH 322251 101 Jor VALA TERRE COMPONENT ARRANGEMENT NE CONVIENT PAS AUX INSTALLATIONS DE PLUS DE 150 SYSTEM TRANSFORMER
49. SHSVG NMOHS 40 IVLSIGINNH OL 03348 OL 15 FU4 FU2 BLK TERM BOARD YEL LS 4 HTR4 BLK o O VV oy YEL SEQ 2 YEL 153 BLK oO 8 152 2 CO YEL 151 SEMI BLK SANA YEL BLU BLK X O YEL BLK BLU DUMMY AC LINE COMMON BLK COMM T2 BLU 208V RED 230V ON TERMINAL BOARD ABOVE EAC2 DUMMY F2 FAN L1 EAC1 240 VAC 240 VAC YEL COMMON CAP F1 COMMON RED LO GRN YEL GND Fig 12 Wiring Schematic 16 97032 BLOWN DIODE b BLOWN O O Sms DIODE a HK61034001A TRANSFORMER AC LINE 1 2 T1 T2 COMMON DUMMY DUMM
50. Shut off power to unit Remove 5 pin plug from motor CAUTION Never remove 5 pin high voltage plug from the motor with the power on Remove 16 pin plug from motor Replace 5 pin plug and turn on power Check for 24v between pin 1 and pin 12 on the 16 pin plug If no voltage is present replace wiring harness See Fig 26 If voltage is present jumper screw terminal R Y Y2 on circuit board and check for 24v between 1 and pin 14 on 16 pin plug See Fig 26 If voltage is present check harness connections G Y1 W1 W2 24v is not present the harness 15 bad Replace harness G Pin 15 Y1 Pin 6 W1 Pin 2 W1 Pin 13 Step 16 Accessories ELECTRONIC AIR CLEANER EAC 230 vac control power signal and EAC2 is not available because the ICM2 blower motor used in the Fan Coil is controlled by low voltage signals This signal is replaced by 33 16 PIN PLUG A94375 Fig 26 Wiring Harness 16 Pin Plug 24 vac signal which is provided at circuit board terminals AUX1 and AUX2 See Fig 23 This signal is present when either or W is present and is active in all heating and cooling modes User supplied 110 vac is switched by relay to power air cleaner when G or W are present See Fig 27 4 S ec 115 VAC BRANCH CKT A
51. The adjust selection options are provided to adjust airflow supplied to meet individual installation needs for such things as noise comfort and humidity removal See Fig 23 AC HP TIME DELAY Select desired time delay profile Four motor operation delay profiles are provided to customize and enhance system operation See Fig 23 The selection options are 1 The standard 90 sec off delay factory setting 0 90 2 No delay option used for servicing unit or when a thermostat is utilized to perform delay functions 0 0 3 A 30 sec on 90 sec off delay profile used when it is desirable to allow system coils time to heat up cool down prior to airflow This profile will minimize cold blow in heat pump operation and could enhance system efficiency 30 90 4 ENH enhanced selection provides a 30 sec on 180 sec off delay at half airflow adding comfort and efficiency CONTINOUS FAN Select desired Continuous fan profile LO MED or HI Airflow are provided to customize and enhance the continous fan functions See Fig 23 The possible selections are 1 LO provides 5090 of Y Y2 Cool airflow 2 MED provides 65 of Cool airflow 71 on FKACNB006 model 3 HI provides 100 of Cool airflow The factory setting is LO NOTE If applied to two speed unit do not select continuous fan as high since LO speed cooling will also run at HIGH airflow and insufficient dehumidification may result Step 13 Troubleshooting PCB Use F
52. Y FAN 1 F1 240 VAC 1 240 97033 13 Control Board Noting Diodes 2 If any of the c diodes are blown the fan is miswired to 1 of the low voltage terminals AUX1 or AUX2 Check to make sure that the fan leads are connected to the proper terminals as shown in Fig 12 If the fan is connected properly make sure that no other high voltage is applied to the AUX terminals THE PCB FUSE KEEPS BLOWING When the low voltage fuse blows it means the transformer would have just blown if the fuse had not been in the circuit to protect it The fuse usually blows when there is a high current draw on the transformer high voltage applied to the low voltage circuit or a direct secondary short When there is a high current draw on the transformer it is most likely because the transformer has been shorted or the system is trying to draw more va than the transformer is rated for When the fuse blows because of high voltage the system has mixed high and low voltage signals 1 Check the transformer and thermostat wiring as shown in Fig 10 Make sure the transformer is not shorting out by the thermostat wires being miswired 2 Check the wiring of the sequencers as shown in Fig 12 Make sure the low voltage and the high voltage wiring are con nected to the proper sequencers Check the va draw on the transformer If the va draw is more than the va rating of the transformer the fuse will
53. Y m iom ES 20 P 4 AUX HUM2 INDOOR THERMOSTAT RECP 1 GRY BK BLU lt 2 RED r3 PCB SEE NOTE 3 YEL Ae 0 572572 Em ORN 00900 RECP 3 RED PLUG 3 scs BRN RED RED 19504131 2 011 619 nus 7 6 5 4 2 1 BLK BLU ORN BRN 4 2 BLK GRY vio 2 5 LEGEND 1 Use copper wire only between disconnect switch and unit 2 Connect Y to Y C to C etc in pattern shown MARKED TERMINAL LS LIMIT SWITCH 3 Transformer primary leads BLUE 208V RED 230V UNMARKED TERMINAL ICM FAN MOTOR 4 To be wired accordandce with and local codes FIELD POWER WIRING TRAN TRANSFORMER 5 If any of the original wire as supplied must be replaced use the same or PLUG RECEPTACLE GND EQUIPMENT GROUND equivalent type wire 6 Replace low voltage fuse with no greater than 5 amp fuse JUMPER ae AGLE 7 Fuse is wired in series between transformer SEC2 and low voltage R circuit AUX 8 20KW heater uses one double pole LS on middle top element PCB PRINTED CIRCUIT BOARD CIRCUIT BREAKER 9 18 24 and 30KW heaters use double pole limit switches HPTB HEAT PUMP TERM BRD F LOW VOLTAGE FUSE 10 Largest heaters are shown smaller heaters will have fewer elements and LVTB LOW VOLT TERM BRD components EQUENCER 11 1 phase heaters are shown wired for single supply circuit Multiple Mee c
54. an input to W2 terminal of control When this occurs control begins sequencing on electric heaters by energizing the first sequencer Indoor fan should be running at this time If room temperature requirements cannot be met additional stages of electric heat are energized through the other 2 sequencers at 2 The logic of control determines how much and how soon these additional stages are brought on By observing LED status light the number of operating stages of electric heat can be determined The control also varies indoor fan speed depending on number of energized stages of heat In general the more stages of electric heat the higher the fan speed There is no hard and fast rule for determining exactly when stages will be energized since microprocessor in the smart control constantly monitors duration of previous heating cycle setting of room thermostat and number of stages of heat needed in previous cycle to satisfy room thermostat Rather than try to determine what should be operating when service technicians should check LED status light to see how many stages of electric heat are energized at a given time and confirm operation of sequencer using a voltmeter If a quick check of all stages is desired set room thermostat as high as it will go With a constant signal on W2T terminal sequencers energize every 10 minutes until all heaters are on The previous paragraphs described how to check for low voltage inputs to control by
55. an only mode a 24 vac signal is sent to relay This causes the relay to close its normally open contacts turning on fan When thermostat no longer calls for the fan the signal sent to relay is turned off and relay opens causing fan to turn off after a 90 sec fan off delay b Sequencer Interlock The fan will also operate whenever there is a call for electric heat even if fan relay is not energized This happens because fan is interlocked with first stage of electric heat through the normally closed contact of fan relay NOTE The fan interlock is only connected to first stage electric heat W2 W3 and E do not contain an interlock with fan See outdoor thermostat Installation Instructions when electric heat staging is desired ELECTRIC HEAT When thermostat calls for electric heat a 24 vac signal is sent to PCB through W2 causing first stage to turn on W3 and E also receive signal if wired in with W2 The signal sent to W2 causes first stage to turn on If W3 and E are not wired to W2 the sequencers can be controlled individually to stage additional electric heat The sequence control is described in the following section 1 W2 When thermostat sends a signal to W2 a 24 vac signal is applied across sequencer number 1 causing it to close after a short delay When sequencer number 1 closes first stage of electric heat is energized In straight electric heat fan is also energized through the normally closed contacts
56. and 9 of 9 pin connector Is connection to board tight CONTINUOUS FAN On a call for continuous fan thermostat provides a 24 v input signal to G terminal on low voltage terminal strip Sensing this signal the microprocessor energizes a relay on control to provide power to high speed winding of fan motor at 1 The fan continues to run until fan switch on thermostat is turned off During continuous fan operation with no call for heating or cooling LED indicates a steady flash the same indication seen when system is in standby The call for continuous fan operation signal can be checked by placing voltmeter leads across terminals G and C of control s low voltage terminal strip If 24v is not seen across these termi nals check for the following Is 24v available across R and If not refer to Ready To Start section for items to check if 24v is not available Is thermostat function switch set for continuous operation Confirm fan operation Voltage to operate fan can be confirmed by placing voltmeter leads across terminals 1 and on control The reading should be 208 230v If 208 230v is not observed check the following s 208 230v available at pins 7 and 9 of 9 pin connector Is connection to board tight e Are line voltage fuses FU1 and FU2 good If 208 230v is available across terminals F1 and HI and fan does not operate check the following s fan motor capacitor good 15 blower wheel jamme
57. anes Do not drop or bend wheel as balance will be affected FG3A SERVICE AND TROUBLESHOOTING Step 1 Service MOTOR Ball bearing oilers are provided on blower motor Use electric motor oil or SAE 10 or 20 nondetergent oil Check motor mount bracket and base bolts Tighten as required BLOWER Check ball bearings for wear Ball bearings are self aligning and grease packed Replace as required Check thrust collars for end play and alignment of wheel Check blades for accumulation of dirt Clean as required Check mounting brackets base bolts and isolation material See Fig 36 for diagram of internal wiring for blower coil assembly Control box standard 4 in junction box is mounted on refrigerant connection side of unit All leads pass through strain relief where they enter control box Wiring inside cabinet is located so it does not come in contact with moving parts or sharp edges BLOWER LINE MOTOR caen GROUND LEAD A91151 Fig 36 Wiring Schematic PULLEY AND BELTS Check belt tension and pulley alignment See Fig 37 Belt tension is adjusted by motor tailpiece bolt A deflection of about 3 4 in to 1 in foot of span should be obtained pressing firmly Lock adjusting bolt in position after adjustment is made Align pulley grooves by locating motor pulley on motor shaft or by moving entire motor along motor mounting bracket Adjust blower speed by loosening setscrew i
58. at the FK4B motor reacts to changes in system static pressures to maintain constant airflow Unlike conventional fan coils where static pressure affects airflow the FK4B is a constant airflow unit The blower delivers requested airflow up to about 0 7 in of static pressure The ICM2 is pre programmed and contains airflows for all modes of operation Blower characteristics airflow torque and speed vs static pres sure are known from laboratory testing If any 3 characteristics are known the fourth is defined Requested airflow is known because of Easy Select board con figuration and thermostat signals Torque is known because it is directly related to armature current which is measured by motor control Speed is measured from its generated back EMF This information is entered into an expression which calculates torque from speed and airflow numbers If calculation does not match stored blower characteristics torque is adjusted every 0 8 sec until agreement is reached The unit does not directly measure static pressure but does react to a change in static to maintain constant airflow DO REMOVE OPTIONAL SAFETY GROUND DRAIN HOLE OPTIONAL SAFETY GROUND 1 6 9 5 POWER CONNECTOR 15 12 13 4 15 19 12 324 5 67 8
59. ate pan is not necessary for upflow or downflow applications 15 Slide complete assembly into unit 16 Reinstall fitting panel and reconnect clip securing fitting panel to condensate drain pan 17 Horizontal Applications Only Reinstall horizontal pan clip Secure with 1 screw See Fig 30 18 Reinstall coil access panel 19 Reconnect liquid and vapor refrigerant tubes and condensate drain tube Install filter drier s if necessary 20 Evacuate tube set and indoor coil back seat open liquid and vapor service valves 21 Turn on electrical supplies to indoor and outdoor units 22 Check system refrigerant charge and operation See Split System Residential Air Conditioners and Heat Pumps Service Manual for further information Step 2 Slope Coil Units If it is determined that system does not have leaks and refrigerant is not contaminated proceed as follows 1 Recover system refrigerant a Attach manifold gage set to service valves b Front seat close liquid tube service valve c Start unit in cooling mode d Run unit until vapor pressure reaches 5 psig 35kPa e Turn off electrical supply to outdoor unit f Front seat vapor service valve g Recover any remaining refrigerant NOTE All outdoor unit coils will hold only factory supplied amount of refrigerant Excess refrigerant such as in long tube applications may cause compressor internal pressure relief valve to open indicated by sudden ri
60. circuit between R and Y is also complete This completed circuit causes contactor in outdoor unit to close which starts compressor and outdoor fan Heating When thermostat calls for heating and FAN switch is set on AUTO the circuit between R and W is complete The heater sequence SEQ is energized which closes contacts of relay There will be a time delay This completed circuit energizes all heating elements HTR and blower motor SCHEMATIC DIAGRAM FOR 2 3 8 5 KW HEATERS COMPONENT ARRANGEMENT BLK SEE RATING PLATE IFR TDR OPTIONAL MOTOR CAP FOR VOLTS amp HZ BLK 3 1 BLK TRANS 24 3 XO DISCONNECT EISE 208 230 O 4106 0 9 6 0 Bu 9 COM BLU RED POWER m SEQ DISCONNECT HTR1 HTR2 L2 TN ASSIS BLU 9 CHASSIS m DE oA GROUND c TRANS CN gt K CR 2 66015 WHEN EQUIPPED 1 8 10 90 00 a ORN C FR O BRN WHEN EQUIPPED 25 BRN CHASSIS GROUND CHASSIS Q GROUND ERI PED CHASSIS VO GROUND MOTOR SPEED SELECTION OPTIONAL IFR TDR e wr HI BLACK LOW RED COMMON VIO SCHEMATIC DIAGRAM FOR 7 5
61. cle Higher ambient temperature means shorter ON times and longer OFF times These sequencers may be ganged up to 3 on common mounting plate to control up to 6 heater elements In this situation PTCs are different in each sequencer to provide a staged ON of a minimum of 10 sec between each sequencer 3 stages of 2 elements since the KFA and series heaters use sequencers in which both switches of the 2 pole sequencer close simultaneously Older models used sequencers which had a minimum delay of 10 sec between each switch Application of these devices is such that the first switch ON not only turns on first heater element but also ensures that indoor fan is energized because first ON is last OFF This ensures fan remains ON until the last heater de energizes POSITIVE TEMPERATURE COEFFICIENT PTC The PTC heater is essentially a resistor It will operate on either AC or DC voltages It should be noted that because resistance of PTC increases as it heats initial current inrush is higher than its steady state condition 18 Step 2 Troubleshooting KFA and KFB Series Electric Heaters DISCOLORED WIRE INSULATION AT TERMINAL Check quick connect terminal at discoloration Connection may be loose creating a high resistance through connection point FUSE FAILURE 1 Check for shorted wire Replace wire Never try to fix wire using electrical tape 2 Check shorted element If element is shorted replace heater NO HE
62. croprocessor 46 to provide a 24 v output signal at terminal Y to energize contactor in heat pump There is a 3 to 5 sec delay in output of Y signal Thirty sec after Y is energized control energizes fan motor It may run on high or low speed depending on its operation in previous cycle Compressor operation in current cycle is monitored by the smart control to determine whether a fan speed change is required for enhanced indoor comfort The LED indicator on control signals 1 flash indicating compressor operation only with no electric heat The call for heat signals can be confirmed by placing voltmeter leads across low voltage terminals Y Y and C The readings should be 24v If 24v is not available check the following Is 24v available across R and C See Ready To Start section for items to check if 24v is not available 15 thermostat function switch set in HEAT position with thermostat calling for heat Assuming heat pump has power and is adequately charged it should be running at this time in heating mode Indoor fan should also be running at this time If indoor fan is not running refer to Continuous Fan section for items to check When room thermostat is satisfied indoor fan continues to run an additional 60 sec to recover heat remaining in indoor coil HEATING COMPRESSOR AND ELECTRIC HEAT If heat pump alone cannot satisfy heat requirements of structure room thermostat calls for additional heat by way of
63. d black fan leads These may be switched at sequencer 2 If PCB has low voltage power check fan relay to see if it is opening and closing It may be stuck in the normally closed position due to debris in relay TRANSFORMER FAILURE 1 Check 208 v and 230 v transformer connections They may be miswired CIRCUIT BOARD FUNCTION AND TROUBLESHOOTING HK61GA001 and HK61GA003 Circuit Boards This section of the service manual describes the HK61GA001 and HK61GA003 printed circuit boards PCB by examining the functional operation of the printed circuit board s components Step 1 PCB Component Layout and Description Layout of the actual printed circuit boards are depicted in Fig 5 and Fig 6 1 The low voltage terminal board is used to connect the indoor thermostat to the low 24 v side of the transformer and to serve as a junction between the indoor thermostat and the outdoor section 2 Break off the tabs a W2 3 Used to control stage the second stage of electric heat The first stage controlling electric heat and the indoor fan are interlocked through diodes b W2 E Used to control stage the third stage of electric heat 3 A fuse is used to protect the low voltage transformer 4 AUX 1 and AUX 2 are connections for the latent capacity control delay off kit 2 speed kit and air conditioning acces sories 5 1 F2 F3 and F4 are connections for the indoor fan 6 EACI and EAC2 are 240 v connection
64. d for 2 speed high COOLING MODE TWO SPEED LOW Thermostat closes circuits R to Y1 and R to O heat pump only The Y1 amp O signals are sent to ICM2 an SEC1 SEC2 SAMP 5 iy SACO EASY SELECT KW CFM R 0 30 0 20 0 10 0 5 1075 875 725 625 vol SIZE 036 030 024 018 Y SYSTEM TYPE HP EFF EUM d AC HP CFM ADJUST or G NOM LO BLK E Qo ON OFF DELAY 0 30 0 90 90 0 WHT O O O CONTINUOUS FAN AUX1 HUM1 9 LO MED C 2 AUX HUM2 8 Je 2 24 PL1 HEATER MOTOR GRY 96430 23 ELECTRIC HEAT HEATING MODE Thermostat closes circuit to W1 amp W2 The terminal block positions W1 and W2 are tied together by jumper J2 is provided for field staging of electric heater banks through use of thermostats When staging is a requirement remove J2 jumper and wire in thermostats as is the
65. d or loose Are there any other mechanical problems preventing fan operation COOLING On a call for cooling room thermostat provides input signals to control board at terminals Y and O The O signal is also available to heat pump to energize reversing valve When it receives both these signals the microprocessor responds by providing a 24 v output signal at the Y terminal This output signal energizes contactor in heat pump and starts compressor There is a 3 to 5 sec delay in output of Y signal At the same time control energizes fan coil s fan motor on high speed through terminals F1 and HI The LED indicator on control signals 5 flashes indicating cooling operation The call for cooling signals can be confirmed by placing voltmeter leads across low voltage terminals Y O Y and C The reading should be 24v If 24v is not available check the following s 24v available across R and C See Ready To Start section for items to check if 24v is not available 15 thermostat function switch set in COOL position with thermostat calling for cooling Assuming heat pump has power and is adequately charged it should be running at this time in cooling mode Indoor fan should also be running at this time If indoor fan is not running refer to Continuous Fan section for items to check HEATING COMPRESSOR ONLY On a call for heat room thermostat provides an input signal to control board at terminal Y This signal causes the mi
66. de of low voltage control power circuit is connected by printed circuit runs to motor connector pins 4 and 5 then through motor control harness to motor ST 8 1 EQ JW2 5i gt 511 9 1 w2 02 SO gt t STi 4 1 02 l SECI R3 1K 2W D7 4 D8 AUX1 ET D4 SEC2 PS1 1 05 Daye 1 4 1 HUM2 2 27 1 1 R2 29 wt 010 C1 1K 2W 145 C2 sn 80 R RED E 80 YiY2 D11 we R1 1K 2W 5200 5540 5000 G00 4 2 CETT ace acs ac4 042 036 030 04 BR AU acs as C 001 ocs CT Pou QH SM QH aco T 7 acto 9 LOW MED Hg CFM TRIM acie T 71 T ON 0 30 30 0 90 90 30 25 ACHP 15 1 2 T 94077 16 Sel
67. device assembly 6 Pull strainer out of coil liquid refrigerant tube and replace with new strainer Step 5 Care and Maintenance A WARNING Hinged access panel contains electrical components and is heavy Support panel when lowering to clean unit to avoid personal injury WARNING Disconnect electrical power to all circuits before servicing unit Failure to do so may result in personal injury from electrical shock or moving parts A WARNING As with any mechanical equipment personal injury can result from sharp metal edges Be careful when removing parts The minimum maintenance requirements for this equipment are as follows 1 Inspect and clean or replace field supplied air filter each month or as required 2 Inspect cooling coil drain pan and condensate drain each cooling season for cleanliness Clean as necessary To be performed by trained personnel 3 Inspect blower motor and wheel for cleanliness each heating and cooling season Clean as necessary 4 Inspect electrical connections for tightness and controls for proper operation each heating and cooling season Service as necessary NOTE Never operate without a filter or with hinged access door open Damage to blower motor may result 42 COOLING COIL DRAIN PAN AND CONDENSATE DRAIN Remember to disconnect electrical power before opening hinged access panel The cooling coil is easily cleaned when dry Inspect coil and clean if necessary
68. e terminal board cannot supply 24 v signal to energize fan motor If transformer is receiving correct primary voltage but is not putting out correct secondary voltage transformer needs to be replaced IF ELECTRIC HEAT STAGES WILL NOT TURN ON BUT FAN WILL TURN ON 1 Check wiring of sequencers Pay particular attention to high and low voltage wiring of sequencers 2 Check plug wiring to make sure that it is wired correctly 3 Check voltage to sequencer Sequencer number 1 receives a 24 vac signal If it is receiving correct voltage check to see if sequencer is closing If sequencer is not closing but is receiving correct voltage replace sequencer If sequencer is closing check high voltage wiring as discussed in items 1 and 2 If There Are Blown Diodes If diodes are blown it is probable electric heater plug is miswired Correct miswiring NOTE Board will need to be replaced if diode is bad If Traces Are Overheated on Back of PCB Usually whenever there is a trace blown on PCB it means either there has been a high voltage short or high voltage has been applied to low voltage circuit This can be prevented by making sure PCB is wired correctly before PCB has power applied to it IF PCB FUSE KEEPS BLOWING When low voltage fuse blows it means transformer would have blown if fuse had not been in circuit to protect it The fuse usually blows when there is a high current drawn on transformer high voltage applied to low v
69. e factory wired at medium speed 2 Functional Control a Thermostat and Relay Control When the thermostat calls for the fan in cooling heat pump electric heat or fan only mode a 24 v dc signal is sent to the relay This causes the relay to close its normally open contacts thus turning on the fan When the thermostat no longer calls for the fan the signal sent to the relay is turned off and the relay opens causing the fan to turn off The HK61GA003 board contains a 90 sec fan off delay when Y is de energized b Sequencer Interlock The fan will also turn on whenever there is any call for electric heat even if the fan relay is not energized This happens because the fan is interlocked with the first stage of electric heat through the normally closed contact of the fan relay ELECTRIC HEAT When the thermostat calls for electric heat a 24 v signal is sent to the PCB through W2 causing the first stage to turn on W3 and E also receive the signal if the tabs are not broken off the PCB The signal sent to W2 causes the first stage to turn on If the tabs are broken off the PCB the sequencers can be controlled individu ally to stage the electric heat The sequence control is described in the following section 1 W2 When the thermostat sends a signal to W2 a 24 v dc signal is applied across sequencer number 1 causing it to close When sequencer number 1 closes the first stage of electric heat energizes after a short delay In
70. eaving evaporator pressure which is transferred via the equalizer tube to underside of diaphragm with which the pin carrier spring pressure closes valve The refrigerant flow is effectively stabilized to load demand with negligible change in superheat The bi flow TXV is used on split system heat pumps In cooling mode TXV operates the same as a standard TXV previously explained However when system is switched to heating mode of operation refrigerant flow is reversed The bi flow TXV has an additional internal check valve and tubing These additions allow refrigerant to bypass TXV when refrigerant flow is reversed with only a 1 to 2 psig pressure drop through device When heat pump switches to defrost mode refrigerant flows through a completely open not throttled TXV The bulb senses the residual heat of outlet tube of coil that had been operating in heating mode about 85 F and 155 psig This temporary not throttled valve decreases indoor pressure drop which in turn increases refrigerant flow rate decreases overall defrost time and enhances defrost efficiency Step 1 Problems Affecting TXV LOW SUCTION PRESSURE 1 Restriction in TXV 2 Low refrigerant charge 3 Low indoor load 4 Low evaporator airflow HIGH SUCTION PRESSURE 1 Overcharging 2 Sensing bulb not secure to vapor tube 3 High indoor load 4 Large evaporator face area 34 When installing or removing TXV wrap TXV with a wet cloth When reattaching TXV
71. eceive a 5 amp automotive type fuse Connection to heater panel is made through 12 circuit connector Connections to thermostat are made at screw terminals Line voltage for ICM2 is made through 7 circuit connector P2 Eighteen quick connect terminals comprise field select taps for motor Fuse Data 5 amp automotive type ATC ATO tan 32 200 percent current opening time 5 sec maximum ELECTRICAL CONNECTIONS Eighteen 0 187 in quick connect terminals are used to provide programming selections for operating modes of ICM2 The 5 selection modes are listed below For additional information refer to Easy Select Configuration Taps section AUX Heat Range Violet Wire Size Blue Wire Type Orange Wire AC HP CFM Adjust Black Wire AC HP Time Delay Grey Wire LOW VOLTAGE TERMINAL BLOCK EASY SELECT AUX HEAT RANGE 512 60 R PRINTED 042 036 030 024 09 CIRCUIT BLU GIGS IS 1 BOARD TYPE AC HP COMFORT HP EFF 09 ORN ACHP CFM ADJUST 00 10 AC HP TIME DELAY 5 CCHS W2 E JUMPER MOLEX 7 d A 3RD STAGE CONNECTOR 18
72. ect Board Circuitry LOW VOLTAGE CIRCUIT FUSING AND REFERENCE The low voltage circuit is fused by a board mounted 5 amp automotive type fuse placed in series with transformer SEC2 and R circuit The C circuit of transformer is referenced to chassis ground through a printed circuit run at SEC1 connected to metal standoff marked GROUND SCREW REQUIRED NOTE A ground screw must be in place or erratic motor operation can result TRANSFORMER MOTOR AND ELECTRIC HEATER POWER CONNECTIONS The high voltage 230 vac power input to board is provided through electric heater connector pins 7 and 9 The high voltage is then connected through printed circuit runs to motor power con nections M1 and M2 and transformer power connections 1 and T3 Transformer connection T2 is a dummy terminal used for unused primary power lead The transformer secondary connec tions are made at SEC1 and SEC2 connectors 21 Step 4 Easy Select Configuration Taps The Easy Select taps are used by installer to configure system The ICM2 uses selected taps to modify its operation to a pre programmed table of airflows Airflows are based on system size or mode of operation and those airflows are modified in response to other inputs such as the need for de humidification See Fig 15 The FK4B Fan Coil must be configured to operate properly with system components with which it is installed To successfully configure a basic system see information printed on circu
73. ed to it the system most likely has 1 of the following problems a Check all 24 v wiring for an electrical short b The maximum load on transformer is 40 va If load on transformer is excessive the low voltage 5 amp fuse will blow to protect transformer If load exceeds va rating of transformer a larger va rated transformer needs to be installed Check sequencers for excessive current draw c Check wiring of heaters If a heater is miswired fuse may blow If a heater is miswired correct miswiring by com paring it to heater wiring label 4 Check connections on primary side of transformer If they are not connected properly the low voltage terminal board cannot supply the 24 v signal to energize fan relay If transformer is receiving correct primary voltage but is not putting out correct secondary voltage transformer needs to be replaced IF ELECTRIC HEAT STAGES WILL NOT TURN ON BUT FAN WILL TURN ON If There Is No High Voltage To PCB 1 Check plug connection between heaters and board This supplies power to transformer and fan Be sure plug is connected properly 2 Check sequencer number 1 and plug wiring Yellow wire should be connected to pin number 9 of plug and to limit switch Black wire should be connected to pin number 7 of plug and to sequencer number 1 3 Check incoming high voltage power leads If these are not receiving power system cannot function If PCB Has High Voltage Applied To It 1 Check low v
74. ent and is active in all heating and cooling modes Because 24 relays may not be readily available to installer a kit exists KFAIROIOIACR containing a 24 vdc relay which mounts directly inside EAC cabinet User supplied 110 vac is switched by relay to power air cleaner when G or W are present See Fig 19 and 20 MOUNT FLUSH WITH THESE TWO EDGES 93216 19 Mounting KFAIRO101ACR Relay Kit In heat pump applications the G signal is present in both cooling and heating modes permitting EAC to be controlled from G signal only For this application a user supplied 24 vac relay can be driven by G terminal eliminating need for relay kit FK4B DE HUMIDIFY MODE NOTE Humidistat must open on humidity rise Latent capacities for systems using the FK4B Fan Coil are better than average systems If increased latent capacity is an application requirement the FK4B can be wired to provide this requirement by adjusting its airflow in response to standard humidistat input Fig 21 illustrates the wiring connections to activate de humidify mode Carefully consult product airflow data for cooling and dehumidi fying mode 26 FK4B 110 VAC BRANCH CKT AUX1 AUX2 GND HOT NEUT hou Sou 6 d OF 24 VDC RELAY a 4 93217 Fig 20 KFAIRO101ACR Relay Kit Wiring Schematic HUMIDISTAT RED WIRE FROM ICM2 A TO PCB T
75. equencer If the sequencer is closing check the high voltage wiring as discussed in 1 and 2 IF THE ELECTRIC HEAT AND THE FAN WILL NOT TURN ON If there is no high voltage to the PCB 1 Check the plug connection This brings power to the PCB transformer and the fan Make sure the plug is connected properly 2 Check sequencer number 1 and the plug wiring The yellow wire should be connected to pin number 9 of the plug and the limit switch The black wire should be connected to pin number 7 of the plug and to sequencer number 1 3 Check incoming high voltage power leads If these are not receiving power the system cannot function If the PCB has high voltage applied to it 1 Check the low voltage transformer leads R and C Make sure they are wired to the correct location The unit will not function without proper connections 2 Check the output voltage of the secondary side R and C of the transformer If the circuit board is an HK61GA003 make sure the ground strap is in place from C to the bracket This strap must be in place to complete the 24 v circuit If the transformer output is zero v ac refer to If the PCB has high voltage applied to it in column 1 numbers 3 and 4 IF THE TRACES ARE BURNT OFF THE BACK OF THE PCB Usually whenever there is a trace blown on the PCB it means either there has been a high voltage short or high voltage has been applied to the low voltage circuit This can be prevented by making sure
76. er 7 of plug and to sequencer number 1 3 Check power leads 1 1 and 12 If these are not receiving power system cannot function If PCB Has High Voltage Applied To It 1 Check low voltage transformer leads red and brown Be sure they are wired to correct locations See Fig 15 and 17 2 Check output voltage of transformer secondary side SEC2 and SECI Be sure transformer output is around 24 vac If transformer output is zero vac and transformer is receiving correct input voltage 208v or 240v then transformer needs to be replaced with recommended transformer If transformer output is 24 vac proceed to items 3 and 4 3 Check low voltage fuse shown in Fig 15 If fuse is blown replace it The transformer cannot supply power to board with fuse blown or loose If fuse blows when unit has power applied to it the system most likely has 1 of the following problems a Check control circuit for a short or miswiring problem b The maximum load on transformer is 40 va If load on transformer is excessive the low voltage 5 amp fuse will blow to protect transformer If load exceeds va rating of transformer a larger va rated transformer needs to be installed Check sequencers for excessive current draw c Check wiring of heaters If a heater is miswired fuse may blow If a heater is miswired correct miswiring 4 Check T2 and T3 connections on primary side of transformer If they are not connected properly low voltag
77. erminal W1 screw terminal 12 Connection Pin 7 Common to W1 screw terminal Pin 8 R 24VAC Pin 9 Common to transformer C Pin 10 Common to transformer C Pin 11 Common to transformer C Pin 12 Common to DH screw terminal The ICM2 power connections are made at the transformer primary terminals The transformer secondary connections are made at SECI and SEC2 connectors Step 12 Easy Select Configuration Taps The Easy Select taps are used by installer to configure system The ICM2 uses selected taps to modify its operation to a pre programmed table of airflows Airflows are based on system size or mode of operation and those airflows are modified in response to other inputs such as the need for de humidification See Fig 23 The Fan Coil must be configured to operate properly with system components with which it is installed To successfully configure a basic system see information printed on circuit board located next to select pins move the 6 select wires to pins which match components used along with homeowner preferences AUXILIARY HEAT RANGE The installer must select the auxiliary heat airflow approved for application with kw size heater installed If no heater is installed skip this step Each select pin is marked with a range of heaters for which airflow also marked is approved The heater installed must fall within range selected for safe and continuous operation It is appropriate to mention t
78. for blocking or restriction that might reduce airflow and cause limit switch to open Operation of heaters can be confirmed further by using a clamp on ammeter in circuit shown to verify current is flowing through heaters Amperage readings will depend on size of heater The procedure for checking other sequencers in system is identical to that just described EMERGENCY HEAT Emergency heat mode requires that room thermostat be placed in EMERGENCY HEAT position This locks out and prevents operation of heat pump outdoor unit In this mode heat is provided exclusively by electrical heaters in fan coil In this mode room thermostat at 1 provides an emergency heat input signal to smart control at terminal W2T If jumper JW1 at 2 has not been cut and an outdoor thermostat installed to control electric heat stages that same input signal is applied to terminal W3 For this example assume that jumper JW1 has not been cut Eventually the total number of heaters is cycled on In emergency heat mode LED indicator signals 7 flashes 47 The amount of emergency heat available depends on whether jumper JW1 is cut and the number of heating elements Table 13 illustrates results under various conditions The heaters cycle on every 5 minutes until maximum level is reached Table 13 Effect of JW1 on Emergency Heat JW1 cut 4 elements 3 elements 50 66 7 JW1 not cut 4 elements 3 elements 10096 10096 Outdoor ther
79. gle phase reciprocating compressors to boost torque to compressor motor so it may overcome the unequalized system pressures The standard TXV is a bi flow metering device that is used in condensing and heat pump systems to adjust to changing load EASY SELECT BOARD TERMINAL BLOCK 7777771 HUMIDISTAT REMOVE d JUMPER 95316 28 Humidistat Wiring De Humidify Mode conditions by maintaining a preset superheat temperature at outlet of evaporator coil The volume of refrigerant metered through valve seat is dependent upon the following 1 Superheat temperature sensed by sensing bulb on suction tube at outlet of evaporator coil As long as this bulb contains some liquid refrigerant this temperature is converted into pressure pushing downward on the diaphragm which opens the valve via push rods 2 The suction pressure at outlet of evaporator coil is transferred via the external equalizer tube to underside of diaphragm 3 The needle valve on pin carrier is spring loaded which also exerts pressure on underside of diaphragm via push rods which closes valve Therefore bulb pressure equals evapora tor pressure at outlet of coil plus spring pressure If load increases temperature increases at bulb which increases pressure on topside of diaphragm which pushes pin carrier away from seal opening valve and increasing flow of refrig erant The increased refrigerant flow causes increased l
80. hat airflow marked is the airflow which will be supplied in emergency heat mode and heating mode on air conditioners when electric heat is primary heating source To ensure safe heater operation in heat pump heating mode when electric heaters are energized the ICM2 will run the higher of heat pump airflow and electric heater airflow The factory selection is largest heater range approved See Fig 23 AC HP SIZE The factory setting for air conditioner or heat pump size is largest unit meant for application with model of fan coil purchased The installer needs to select air conditioner or heat pump size to ensure that airflow delivered falls within proper range for size of unit installed in all operational modes See Fig 23 SYSTEM TYPE The type of system must be selected 1 conditioner 2 HP COMFORT provides lower airflow than air conditioner selection approximately 315 CFM ton in heating mode In cooling made supplies 350 CFM ton 3 HP EFF provides same airflow for heating and cooling modes approximately 350 The factory setting is AC See Fig 23 30 AC HP CFM ADJUST Select low nominal or high airflow To provide any of these airflows AC HP ADJUST select must be moved to NOM position The factory selection is NOM The adjust selections HI LO will regulate airflow supplied for all operational modes except non heat pump heating modes 15 percent and 10 percent respec tively
81. iagram See Fig 34 Step 2 Electric Heater Service Service can be completed with heater in place Shut off power before servicing LIMIT SWITCH Malfunction prevents heating element from coming on Replace switch if malfunction occurs SEQUENCER Malfunction causes heater not to come on never shut off Replace sequencer TRANSFORMER A 60 va transformer supplies 24 v power for control circuit Replace transformer if faulty NOTE Transformer is fused Do not short circuit FAN RELAY Malfunction causes unit fan not to run or run continuously Replace relay HEATER REMOVAL Disconnect wiring remove 2 sheet metal screws and pull heater out through open hinged access panel When replacing heater ensure orientation of heater element is same as when removed 40 Step 3 Cleaning or Replacing Refrigerant Flow Control Device Pump down outdoor unit Close service valves at outdoor unit CAUTION Damage may occur to scroll compressor if operated at a negative suction pressure during a system pumpdown 2 Bleed and if possible recover remaining refrigerant from tubing and coil through gage port on vapor tube service valve 3 Disconnect liquid refrigerant tube from refrigerant flow control device Refer to Fig 35 4 Remove refrigerant flow control device piston retainer Avoid damaging O ring or machined surfaces on piston bore and retainer 5 Using small wire with a hook on end
82. ig 24 and 25 and Tables 7 and 8 as guides in troubleshooting PCB unless otherwise noted IF FAN WILL NOT TURN ON FROM THERMOSTAT If There Is No High Voltage To Motor 1 Check connection of 12 pin plug from heaters to receptacle This supplies power to transformer and motor Be sure plug is connected properly THIS COMPARTMENT MUST CLOSED EXCEPT FOR SERVICING CAUTION NOT SUITABLE FOR USE ON SYSTEMS EXCEEDING BLOWER MOTOR 150V TO GROUND ROTATION ATTENTION ee PAS AUX INSTALLATIONS DE PLUS DE 150 V ALA TERRE SCHEMATIC DIAGRAM LEGEND LS SWITCH COM COMMON MARKED TERMINAL 2 WIRING SEE F1 LOW VOLTAGE FUSE gt PLUG AND RECEPTACLE 8 5 8 HERTZ ICM MOTOR PRINTED CIRCUIT BOARD mi X 1 FIELD POWER WIRING SEQ SEQUENCER FU LINE FUSE TRAN TRANSFORMER i GND EQUIPMENT GROUND RECP RECEPTACLE HVTB HIGH VOLTAGE TERM BLOCK CB CIRCUIT BREAKER NYELTFUSP YEL SEM HTR HEATER xD FIELD POWER WIRING COOLING CONTROL ONLY 7 1 YEE YEL FIELD 153 WIRING 52 YEL BLK ES CB FU1 9 3 2 6 1 4 PLUG 2 VELO A 208 240VAC 24VAC 24VAC E 9 1 7
83. ignal from thermostat w3 Connection for W3 signal from outdoor thermostat E Connection for E signal from thermostat Y Y2 Connection for Y signal from thermostat G Connection for G signal from thermostat Connection for signal from thermostat L This connection is a field termination for use in connecting L lines of thermostat and outdoor unit together There is no connection of this terminal with control circuity Y1 Connection for low speed compressor operation R Connection for R signal to thermostat 24 vac Connection for terminal to thermostat 24 vac common Table 5 Connections and Connector TYPE TYPE CONNECTION CONNECTOR DESCRIPTION Pin 1 Common to E screw terminal Pin 2 Common to W2 screw terminal Pin Common to C screw terminal SEC1 terminal and chassis ground Pin 4 Common to C screw terminal SEC1 terminal and chassis ground Pin 5 No connection Heater 12 Pin Pin 6 Common to screw terminal Connection Pin 7 Common to M2 and T3 quick connects 230 vac input Pin 8 No connection Pin 9 Common to M1 and T1 quick connects 230 vac input Pin 10 No connection Pin 11 No connection Pin 12 No connection Pin 1 Diode OR output of E or W3 or W2 thermostat signals Pin 2 Thermostat G signal Pin 3 Common to C SEC1 and chassis ground ICM2 Motor 7 Pin Header Pin 4 Common to C and chassis ground Pin 5 Common to R and SEC2 via 5 amp fuse Pin 6 Thermostat Y Y2 signal Pin 7 Thermostat Y1 signal fall with
84. imum maintenance requirements for this equipment are as follows 1 Inspect and clean or replace air filter each month or as required 2 Inspect cooling coil drain pan and condensate drain each cooling season for cleanliness Clean as necessary 3 Inspect blower motor and wheel for cleanliness each heating and cooling season Clean as necessary 4 Inspect electrical connections for tightness and controls for proper operation each heating and cooling season Service as necessary A WARNING As with any mechanical equipment personal injury can result from sharp metal edges Be careful when removing parts AIR FILTER To clean or replace air filter grasp it at bottom and lift it out of unit Clean filter using cold water Rinse clean and let dry Oiling or coating of filter is not required To replace stand filter in rack with binding facing coil Press top edge under access panel NOTE Steel rods in filter prevent it from being pulled into coil Retain these rods and reinstall after cleaning or before replacement if new filter is used CAUTION Never operate unit without a filter COOLING COIL DRAIN PAN AND CONDENSATE DRAIN The cooling coil is easily cleaned when it is dry Inspect coil and clean if necessary before each cooling season To check or clean cooling coil remove blower heater access panel to gain full access to cooling coil If coil is coated with dirt or lint vacuum with a soft brush attachmen
85. in Fig 23 If fuse is blown replace it The transformer cannot supply power to board with fuse blown or loose If fuse blows when unit has power applied to it the system most likely has 1 of the following problems a Check control circuit for a short or miswiring problem b The maximum load on transformer is 40 va If load on transformer is excessive the low voltage 5 amp fuse will blow to protect transformer If load exceeds va rating of transformer a larger va rated transformer needs to be installed c Check sequencers for excessive current draw d Check wiring of heaters If a heater is miswired fuse may blow If a heater is miswired correct miswiring 3 Check yellow and black wire connections on primary side of transformer If they are not connected properly low voltage transformer cannot supply 24 v signal to energize fan motor If transformer is receiving correct primary voltage but is not putting out correct secondary voltage transformer needs to be replaced IF ELECTRIC HEAT STAGES WILL NOT TURN ON BUT FAN WILL TURN ON 1 Check wiring of sequencers Pay particular attention to high and low voltage wiring of sequencers 2 Check plug wiring to make sure that it is wired correctly 3 Check voltage to sequencer Sequencer number 1 receives a 24 vac signal If it is receiving correct voltage check to see if sequencer is closing If sequencer is not closing but is receiving correct voltage replace sequencer
86. in range selected for safe and continuous operation It is appropriate to mention that airflow marked is the airflow which will be supplied in emergency heat mode and heating mode on air conditioners when electric heat is primary heating source To ensure safe heater operation in heat pump heating mode when electric heaters are energized the ICM2 will run the higher of heat pump efficiency airflow and electric heater airflow The factory selection is largest heater range approved See Fig 15 AC HP SIZE 22 The factory setting for air conditioner or heat pump size is largest unit meant for application with model of fan coil purchased The installer needs to select air conditioner or heat pump size to ensure that airflow delivered falls within proper range for size of unit installed in all operational modes See Fig 15 SYSTEM The type system must be selected 1 AC air conditioner 2 HP COMFORT provides same airflow as air conditioner selection approximately 375 CFM ton 3 HP EFF provides most efficient airflow for heating and cooling modes approximately 410 CFM ton heating and 375 CFM ton cooling The factory setting is AC See Fig 15 AC HP CFM ADJUST Select low medium or high airflow To provide any of these airflows AC HP ADJUST select must be moved to MED position The factory selection is LO The adjust selections HI LO will regulate airflow supplied for all operational modes except non
87. it board located next to select pins move the 5 select wires to pins which match components used AUXILIARY HEAT RANGE The installer must select the auxiliary heat airflow approved for application with kw size heater installed If no heater is installed skip this step Each select pin is marked with a range of heaters for which airflow also marked is approved The heater installed must Table 3 Male Female Quick Connect Terminals SIZE FEMALE SIZE MALE DESCRIPTION M2 Motor line voltage connection 230 vac 60 Hz T3 Transformer line voltage connection 230 vac 60 Hz T2 Transformer tap storage terminal for 208 vac lead connection from transformer 24 vac This connection is common to chassis ground through eyelet marked GROUND SCREW REQUIRED 0 250 X 0 032 SEC2 Secondary connection from transformer 24 vac HUM1 Low voltage ground for humidifier option 24 vdc HUM2 Low voltage output for humidifier option 24 vdc AUX1 Low voltage ground for auxiliary option 24 vdc AUX2 Low voltage output for auxiliary option 24 vdc M1 Common connection to blower motor 0 187 X 0 032 T1 Common connection for transformer RED Common to R screw terminal and SEC2 Table 4 Connections on Single Barrier Strip Mounted Cross Slotted Captive Binding Head SCREW TERMINAL DESCRIPTION Connection for W2 s
88. l stages tied together If independent staging is desired consult outdoor ther mostat Installation Instructions Step 3 Troubleshooting the Printed Circuit Board Use wiring schematic shown in Fig 4 as a guide in troubleshooting PCB unless otherwise noted IF FAN WILL NOT TURN ON FROM THERMOSTAT If There Is No High Voltage To PCB 1 Check plug receptacle connection This supplies power from heaters to PCB Be sure plug is connected properly 2 Check sequencer number 1 and plug wiring Yellow wire should be connected to pin number 9 of plug and to limit switch Black wire should be connected to pin number 7 of plug and to sequencer number 1 3 Check power leads 1 1 and 12 If these are not receiving power system cannot function If PCB Has High Voltage Applied To It 1 Check low voltage transformer leads R red and C brown Be sure they are wired to correct locations 2 Check output voltage of transformer secondary side R red and C brown Be sure transformer output is between 18 and 30 vac If transformer output is incorrect and transformer is receiving correct input voltage 208v or 230v then trans former needs to be replaced with recommended transformer If no problem exists with transformer secondary proceed to items 3 and 4 3 Check low voltage fuse shown in Fig 3 If fuse is blown replace it The transformer cannot supply power to board with fuse blown or loose If fuse blows when unit has power appli
89. ly to outdoor unit immediately front seat vapor service valve and recover any remaining refrigerant 2 Turn off electrical supply to indoor unit 3 Disconnect condensate drain tube 4 Disconnect liquid and vapor tubes from indoor coil Use a tubing cutter to cut tubes NOTE If a torch is used to unbraze tube set protect fitting panel with a wet cloth or braze shield as necessary 5 Remove coil access panel 35 6 Remove clip securing fitting panel to condensate drain pan Remove fitting panel 7 Remove any shipping clips including horizontal pan clip and slide coil condensate pan assembly out of unit 8 Upflow or Horizontal Applications Only Remove hori zontal condensate drain pan from coil condensate pan assem bly See Fig 30 9 Remove 4 coil brackets See Fig 30 10 Remove screws at delta plates and remove coil from vertical condensate drain pan See Fig 30 11 Horizontal Applications Only Remove coil top seal at tached with 4 screws and J shaped tube from original coil and install it in same position on new coil See Fig 30 12 Place coil assembly in plastic condensate pan and secure using 4 screws through delta plate See Fig 30 13 Horizontal and Upflow Applications Only Attach 4 coil brackets to coil pan assembly See Fig 30 14 Horizontal Applications only Place horizontal condensate pan into position on coil pan assembly NOTE Installation of horizontal condens
90. mostat opens With JW1 cut an outdoor thermostat if closed could cycle on additional heaters and system would perform as if JW1 was not cut In effect closed outdoor thermostat replaces cut jumper DEFROST In defrost mode LED indicator signals 6 flashes Defrost is initiated by heat pump and is signalled to smart control by an input to W2D terminal During defrost outdoor unit switches to cooling mode making it necessary to cycle on electric heaters to temper indoor air If electric heaters were not energized prior to defrost smart control energizes sufficient elements to temper air If heaters were energized prior to defrost additional heaters may or may not be cycled on to provide additional heat A defrost initiation signal can be confirmed by attaching voltmeter leads across low voltage terminals W2D and C If 24v is not observed check the following Is 24v available across R C See Ready To Start section for items to check if 24v is not available Is there continuity in thermostat leads between heat pump and smart control Is defrost control in heat pump operating properly THIS COMPARTMENT MUST CLOSED EXCEPT FOR SERVICING CAUTION N NOT SUITABLE FOR USE ON SYSTEMS EXCEEDING BLOWER MOTOR 150V TO GROUND ATTENTION ROTATION SCHEMATIC DIAGRAM FIELD POWER WIRING 9 21 DISCONNECT PER SEE RATING PLATE FOR VOLT
91. n outer moveable pulley face and turning this face half or full turns so that adjusting setscrew is positioned precisely over the flat on pulley hub Speed is reduced by adjusting pulley faces so they are further apart speed is increased with faces closer together Check pulley setscrews and bolts MUST PARALLEL FOR PROPER ALIGNMENT PULLEY ALIGNMENT BELT ADJUSTMENT A91150 37 Checking Pulley Alignment and Tightness CLEANING OR REPLACING REFRIGERANT FLOW CONTROL DEVICE Refer to Fig 35 and instructions given in FD3A Service and Troubleshooting section above Step 2 Maintenance A WARNING Disconnect electrical power to all circuits before servicing unit Failure to do so may result in personal injury from electrical shock or moving parts A WARNING As with any mechanical equipment personal injury can result from sharp metal edges Be careful when removing parts RETURN AIR FILTER To clean or replace air filter remove screws and filter access door Slide out filter For washable type filters clean with hot soapy water Rinse clean and let dry New filters are available from a local distributor Place filter in slot with filter arrow facing direction of airflow Replace filter access doors with screws previously removed CAUTION Never operate unit without a filter or with filter access door removed Damage to blower motor may result COIL DRAIN PAN AND CONDENSATE DRAIN
92. nt replace board ROOM THERMOSTAT Remove thermostat wires from the circuit board Jumper screw terminals 1 at a time R Y Y2 1 and R W2 If motor runs in all cases thermostat is bad Replace thermostat If motor does not run or runs in some cases but not in others continue by checking the wiring harness WIRING HARNESS Shut off power to unit Remove 5 pin plug from motor CAUTION Never remove 5 pin high voltage plug from motor with the power on Remove 16 pin plug from motor Replace 5 pin plug and turn on power Check for 24v between pin 1 and pin 12 on the 16 pin plug If no voltage is present replace wiring harness See Fig 9 If voltage is present jumper screw terminal R Y Y2 circuit board and check for 24v between pin 12 and pin 14 on 16 pin plug See Fig 18 If voltage is present replace harness If 24v is present the motor is bad Replace motor Step 8 Accessories ELECTRONIC AIR CLEANER EAC Familiar 230 vac EAC control power signal EAC1 and EAC2 is not available because the ICM2 blower motor used in the FK4B 16 PIN PLUG A94375 Fig 18 Wiring Harness 16 Pin Plug Fan Coil is controlled by low voltage signals This signal is replaced by a 24 signal which is provided at circuit board terminals AUX1 and AUX2 See Fig 15 This signal is present when either G or W is pres
93. of fan relay In cooling heat pump or manual fan mode fan will already be running since fan relay would have been energized When thermostat stops calling for electric heat the 24 vac signal to sequencer number 1 turns off and sequencer opens after a delay of 60 to 90 sec When sequencer opens first stage of heat turns off along with fan providing thermostat is not calling for the fan 2 W3 When a signal is sent to W3 a 24 vac signal to sequencer number 2 causes sequencer to close with second stage of electric heat turning on after a short delay The 24 vac signal applied to sequencer number 1 causes fan to operate Timing is such that sequencer number 1 will turn on before sequencer number 2 When signal to W3 is turned off sequencer number 2 opens after a short delay If W2 is also satisfied first stage of electric heat and fan will also turn off providing thermostat is not calling for the fan 3 When thermostat sends a signal to 24 vac signal is sent to sequencer number 3 The 24 vac signal applied to sequencer number 3 turns on third stage of electric heat The 24 vac signal applied to sequencer number 1 turns on first stage of electric heat and fan When thermostat stops calling for electric heat the signal to sequencers 1 2 and 3 are turned off and sequencers open This causes electric heat to turn off with fan providing thermostat is not calling for the fan NOTE Electric heaters are factory wired with al
94. oltage circuit or a direct secondary short When there is a high current drawn on transformer it is most likely because transformer has been shorted or system is trying to draw more va than transformer rating allows When fuse blows because of high voltage the system has mixed high and low voltage signals 1 Check transformer and thermostat wiring See Fig 15 and 17 Be sure transformer is not shorting out because thermostat wires are miswired 2 Check wiring of sequencers See Fig 15 and 17 Be sure low voltage and high voltage wiring are connected to proper sequencers 3 Check va draw on transformer If va draw is more than va rating of transformer fuse will blow If this is the case replace transformer with one that has a higher va rating and meets system specifications Step 6 Troubleshooting ICM2 Fan Motor IF MOTOR DOES NOT RUN 1 With power turned off check all plugs and receptacles on circuit board and at motor for any deformation that may cause a bad connection Be sure all plugs are placed fully seated THIS COMPARTMENT MUST CLOSED EXCEPT FOR SERVICING BLOWER MOTOR ROTATION CAUTION NOT SUITABLE FOR USE ON SYSTEMS EXCEEDING 150V TO GROUND ATTENTION NE CONVIENT PAS AUX INSTALLATIONS DE PLUS DE 150 ALA TERRE
95. oltage transformer leads R red and C brown Make sure they are wired to correct location The unit will not function without proper connections 2 Check output voltage of transformer secondary side R red and C brown If transformer output is low less than 18 vac refer to items 3 and 4 of previous If PCB Has High Voltage Applied To It section If Traces Are Overheated on Back of PCB Usually whenever a trace is blown on PCB it means either there has been a high voltage short or high voltage has been applied to low voltage circuit This can be prevented by making sure PCB is wired correctly before PCB has power applied to it BLOWER MOTOR ROTATION THIS COMPARTMENT MUST BE CLOSED EXCEPT FOR SERVICING NOT SUITABLI 150V TO GRO CAUTION E FOR USE ON SYSTEMS EXCEEDING UND ATTENTION 80KW SCHEMATIC DIAGRAM _ LEGEND FIELD POWER WIRING DISCONNECT PER CAP CAPACITOR LS LIMIT SWITCH SEE RATING PLATE COM COMMON MARKED TERMINAL B 2 FOR VOLTS 8 HERTZ 4 LOW VOLTAGE FUSE PLUG AND RECEPTACLE i o GND FAN MOTOR PCB PRINTED CIRCUIT BOARD dull en SER NOTE eacus e FIELD POWER WIRING SEQ SEQUENCER FR FAN RELAY TRAN TRANSFORMER FU O UNMARKED TERMINAL GND EQUIPMENT GROUND RECP RECEPTACLE HIGH VOLTAGE TERMBLOCK CB CIRCUIT BREAKER HEATE
96. ondensate drain tube Install filter drier s if necessary 17 Evacuate tube set and indoor coil back seat open liquid and vapor service valves 18 Turn on electrical supplies to indoor and outdoor units 19 Check system refrigerant charge and operation See Split System Residential Air Conditioners and Heat Pumps Service Manual for further information CARE AND MAINTENANCE To continue high performance and minimize possible equipment failure it is essential periodic maintenance be performed on this equipment COIL SUPPORT COLUMN COIL TOP SEAL PARTIALLY HIDDEN CASING DISTRIBUTOR TUBE EXPANSION DEVICE PISTON SHOWN 9 pee SCREW PAN TO COIL LIQUID TUBE FIELD CONNECTION COLUMN CONDENSATE PAN SCREW 90269 31 Slope Component Location 36 The ability to properly perform maintenance on this equipment requires certain mechanical skills and tools The only consumer service recommended or required is filter maintenance See Filter Assembly A WARNING Disconnect all power to the unit before servicing the field wires or removing the control package The disconnect when used on the access panel does not disconnect power to the line side of the disconnect but does allow safe service to all other parts of the unit Electrical shock can cause personal injury or death The minimum maintenance requirements fo
97. ontinues to run remove the 7 pin plug If motor continues to run replace motor Step 7 Condensed Version of Troubleshooting FK4B Motor and Controls This section provides a quick summary of how to troubleshoot the FK4B If more information is needed refer to appropriate sections of this service manual MOTOR If motor is hard to turn manually replace motor If motor does not run check the components listed below according to their instructions If motor runs in some operation modes and not in others check for a good ground connection between motor ground lead or any combination of heater inputs are energized 25 and circuit board screw marked ground screw and check the room thermostat and wiring harness according to instructions listed below If motor does not stop running remove the 7 pin plug from circuit board If motor continues to run replace motor If motor stops running it is either the circuit board or thermostat causing the problem Test whether thermostat is at fault by disconnecting it from the board CIRCUIT BOARD Check 5 amp fuse Check for 230v between terminals and 2 If no voltage is present check power to board 230 v power enters the board through the black and yellow lead in the 12 pin plug Check for 24v between SEC1 and 5 2 If no voltage is present check the transformer Check for burn traces or burnt components If burn spots are prese
98. operation high speed for cooling heat pump and fan only modes Low speed is used for electric heat Fig 8 shows proper connection for 24 v dc 2 speed fan relay kit Note that kit s relay coil is in parallel with fan relay coil on PCB connected to AUX1 and AUX2 Make sure the normally closed contact is connected to the lower speed b The latent capacity control kit is used to control fan speed operation when the relative humidity is above a set point on humidistat Humidistat opens and 2 speed fan relay re mains in normally closed position with fan motor running at a lower speed for maximum humidity control Fig 9 shows proper connection for latent capacity control kit Note that it is connected in the same manner as 2 speed fan relay kit but with relay connected to humidistat orange wires c Time delay off relay kit is used to increase the efficiency of the system by delaying the fan from turning off after the thermostat is satisfied on HK61GA001 board The HK61GA003 board has this feature as standard The proper wiring and mounting of the time delay off relay kit is shown in Fig 10 d Latent capacity control and time delay off connections are shown Fig 11 for the HK61GA001 board only Step 3 Troubleshooting the Printed Circuit Board Use Fig 12 wiring schematic as a guide in troubleshooting the PCB unless otherwise noted IF THE FAN WILL NOT TURN ON FROM THE THERMO STAT If there is no high voltage to the
99. placing voltmeter leads across low voltage terminal strip and checking for 24v The call for electric heat can be confirmed by placing voltmeter leads across W2T and C To check for operation of sequencers check directly across appropriate sequencer coil for 24 volts DC NOTE sequencer coils are powered by 24 volts DC This voltage is generated internally by the smart control In this example sequencer 1 is being checked The procedure is the same for all other sequencers If 24 volts DC is not observed check the following Is room thermostat calling for electric heat This can be confirmed by checking for 24 volts AC between low voltage terminal strip terminals W2T and C Is LED flashing appropriate code for number of sequencers energized In this example 2 flashes should be visible indicating 1 sequencer is energized Indicator tells how many sequencers are energized but does not tell which ones are Is 9 pin connector for heater package tightly secured to control board CHECKING SEQUENCER OPERATION To check for operation of power circuit of sequencer place voltmeter leads across sequencer terminal 1 of sequencer 1 and terminal 4 of limit switch 3 The reading should be 208 230v and heater should be energized If 208 230v is not observed at terminals specified check the following Are fuses FU3 and FU4 good Is limit switch 1 53 open If so check fan coil air filter or air distribution system
100. quencer number 1 through the diode interlock and a 24 v ac signal to sequencer number 2 The 24 v ac signal applied to sequence number 2 causes the sequencer to close with the second stage of electric heat turning on after a short delay The 24 v dc signal applied to sequencer number 1 causes the first stage of electric heat to turn on in the same manner as described in W2 above Note that W3 is interlocked with the fan since sequence number 1 is turned on whenever W3 has a signal sent to it Timing is such that sequence number 1 will turn on before sequence number 2 When the signal to W3 is turned off sequencer number 2 opens after a short delay If W2 is also satisfied the first stage of electric heat and the fan will also turn off providing the thermostat is not calling for the fan to be on E When the thermostat sends a signal to E 2 signals are sent out to the sequencers 24 v ac signal is sent to sequencer number 3 and a 24 v dc signal is sent to sequencer number 1 The 24 v ac signal applied to sequencer number 3 turns on the third stage of HK61GA003 FAN INTERLOCK DIODES AND FAN TIME DELAY OFF LOW VOLTAGE TERMINAL BOARD 2FD 1 2ND STAGE W2 3 ELECTRIC HEAT BREAKOFF TABS FOR STA
101. r housing before disassembly to ensure proper reassembly Note position of blades on wheel Loosen setscrew holding blower wheel onto motor shaft Remove 3 bolts holding motor mount to blower housing and slide motor and mount out of housing Further disassembly should not be necessary as adequate clearance is available Remove blower wheel from housing by removing cutoff plate from blower housing outlet Note wheel orientation and cutoff location for reassembly The blower motor and wheel may be cleaned by using a vacuum with a soft brush attachment Remove grease with a mild solvent such as hot water and detergent Be careful not to disturb balance weights clips on blower wheel vanes Also do not drop or bend wheel as balance will be affected To reassemble blower 1 10 Place blower wheel back into housing Be sure to position correctly for proper location Reassemble cutoff plate to housing using identified holes from disassembly procedure Position motor and mount in same position as when blower housing was in unit Secure motor mount on housing using removed bolts Make sure mount or motor is grounded to blower housing Locate blower wheel setscrew over flat on motor shaft Rotate wheel in housing It should not rub housing and should be centered in inlet opening If not loosen setscrew and align as necessary Attach green wire to blower housing with screw Secure motor capacitor
102. r this equipment are as follows 1 Inspect and clean or replace air filter each month or as required 2 Inspect cooling coil drain pan and condensate drain each cooling season for cleanliness Clean as necessary An inspec tion port is provided on all A coil delta plates Remove plastic plug to inspect Replace plug after inspection 3 Inspect blower motor and wheel for cleanliness each heating and cooling season Clean as necessary 4 Inspect electrical connections for tightness and controls for proper operation each heating and cooling season Service as necessary A WARNING As with any mechanical equipment personal injury can result from sharp metal edges Be careful when removing parts Step 1 Filter Assembly To clean or replace air filter push plastic connectors toward center of unit and remove filter access panel outward Push filter up and back into unit Then slide filter out Clean filter by using cold water and mild detergent Rinse and allow filter to dry No oiling or coating of filter is required New filters are available from your local distributor Place filter in slot with cross mesh binding up or facing cooling coil and replace filter access panel Step 2 Cooling Coil Drain and Condensate Drain The cooling coil is easily cleaned when it is dry Inspect the coil and clean if necessary before each cooling season To check or clean cooling coil remove coil access panel If coil is coa
103. ration to a pre programmed table of airflows and can be modified in response to other inputs such as the need for de humidification ICM2 CONTROL POWER The ICM2 control power is supplied from R circuit through printed circuit runs to motor control connector pin 8 through motor control harness to motor The C side of low voltage control power circuit is connected by printed circuit runs to motor connector pins 9 10 and 11 then through motor control harness to motor 29 LOW VOLTAGE CIRCUIT FUSING AND REFERENCE The low voltage circuit is fused by a board mounted 5 amp automotive type fuse placed in series with transformer SEC2 and R circuit The C circuit of transformer is referenced to chassis ground through a printed circuit run at SEC1 connected to metal standoff marked NOTE The PCB must be mounted with 2 screws and motor ground lead secured to blower housing or erratic motor operation can result TRANSFORMER MOTOR AND ELECTRIC HEATER POWER CONNECTIONS Transformer high voltage supplied from electric heater package or high voltage leads through 12 pin heater connector plug recp 2 Table 8 Connections and Connector TYPE TYPE CONNECTION CONNECTOR PIN NO DESCRIPTION Pin 1 Common to screw terminal G Pin 2 Common to screw terminal Y Y2 through diode D3 Pin 3 Common to Y1 through diode D2 Pin 4 Common to W2 screw terminal Pin 5 Common to W2 screw terminal Heater 6 Common to screw t
104. roblems a If the transformer is shorting out check the wiring of the transformer 11 b The maximum load on the transformer is 40 va If the load on the transformer is excessive the low voltage 5 amp fuse will blow to protect the transformer If the load exceeds the va rating of the transformer a larger va rated transformer needs to be installed Check the sequencers for excessive current draw c Check the wiring of the heaters If the heater is miswired the fuse may blow Check the diodes shown in Fig 13 for signs of overheating If the heater is miswired correct the miswiring 4 Check the T1 T2 and T3 connections on the primary side of the transformer If they are not connected properly the low voltage terminal board cannot supply the 24 v signal to energize the fan relay If the transformer is receiving the correct primary voltage but is not outputting the correct secondary voltage the transformer needs to be replaced IF THE ELECTRIC HEAT STAGES WILL NOT TURN ON BUT THE FAN WILL TURN ON 1 Check the wiring of the sequencer Pay particular attention to the high and low voltage wiring of the sequencers 2 Check the plug wiring to make sure that it is wired correctly 3 Check the voltage to the sequencer sequencer number 1 receives a 24 vac signal If it is receiving the correct voltage check to see if the sequencer is closing If the sequencer is not closing but is receiving the correct voltage replace the s
105. rrent switch When system temperatures cool sufficiently the switch will automatically reset to its closed position Normal failure mode for this switch is open If a limit switch has been determined to be defective NEVER BYPASS THE LIMIT SWITCH When replacing limit switch ensure that it is replaced with a limit switch of identical opening temperature and closing differential Limits switches are typically color coded to identify their range SEQUENCER The sequencer is essentially a thermally activated time delay relay normally activated by low voltage control signals from thermostat The typical sequencer is a 1 or 2 pole normally open device which energizes within 10 to 30 sec after application of control signal and de energizes 60 to 90 sec after control signal is removed In simplistic terms the sequencers which we use are nothing more than normally open limit switches which sit on top of a small resistive heater When voltage is applied to this heater a positive temperature coefficient resistor PTC heat is supplied to a bimetallic disc which snaps through and closes switch The time required for PTC to heat to a sufficient point controls ON timing of device The time required for disc to cool down when power is removed controls OFF time of device The PTC can be varied to provide varied timing Typically a short ON equates to a long OFF Because this is a thermally activated device ambient conditions affect the ON OFF cy
106. s which parallel fan lead connections for the electronic air cleaner 7 L1 and L2 are 240 v connections which parallel power input 8 T1 T2 and T3 are connections for the primary high voltage side of the transformer 9 The fan relay is controlled by the thermostat and turns the fan on and off 10 A plug is used as the connection for the PCB power and electric heaters Note the pin numbers on the plug 11 Diodes provide DC power for the fan relay and the first stage of electric heat W2 W3 or E Step 2 PCB Component Functions LOW VOLTAGE TERMINAL BOARD The low voltage terminal board connects the indoor thermostat to the outdoor unit as shown in Fig 7 The terminals are listed as follows along with their functional control 1 Ris used to connect the secondary side of the transformer The red wire provides low voltage 24v to the PCB and the thermostat R is fused the HK61GA003 board 2 C is used to connect the brown wire of the thermostat to provide a return path to ground through the fuse which protects the transformer C is fused on the HK61GA001 board 3 G is used to control the switching of the relay to turn the fan on through the normally open contact of the relay 4 Y on HK61GA001 is used as the junction for the outdoor section s Y connection which controls the compressor contac tor for heat pump and cooling modes The HK61GA003 board contains a 90 sec fan off delay which begins timing when the
107. se in vapor pressure before vapor pressure reaches 5 psig 35kPa If this occurs turn off electrical supply to outdoor unit immediately front seat vapor service valve and recover any remaining refrigerant 2 Turn off electrical supply to indoor unit 3 Disconnect condensate drain tube 4 Disconnect liquid and vapor tubes from indoor coil Use either a tubing cutter to cut tubes or a torch to unbraze tubes as required NOTE If a torch is used to unbraze line set protect fitting panel with a wet cloth or braze shield as necessary System contains oil vapors which may ignite when exposed to a flame 5 Remove coil access and fitting panels 6 Remove 1 screw securing coil to unit casing 7 Remove coil pan assembly from unit 8 Place assembly on a flat surface Remove 2 screws securing coil support columns to pan See Fig 31 9 Rotate columns 90 pull away from coil and remove columns from assembly 10 Remove remaining 2 screws securing coil to condensate pan 11 Remove coil from condensate pan 12 Remove coil top seal See Fig 31 13 Install new coil into condensate pan using 2 original screws and 2 support columns NOTE Correct coil position in condensate pan is essential to reliable operation 14 Install new coil pan assembly into unit Secure with 2 screws previously removed from unit casing 15 Reinstall coil access and fitting panels 16 Reconnect liquid and vapor refrigerant tubes and c
108. t Be careful not to bend coil fins If coil is coated with oil or grease clean it with a mild detergent and water solution Rinse coil with clear water Be careful not to splash water onto insulation Inspect drain pan and condensate drain at same time cooling coil is checked Clean drain pan and condensate drain by removing any foreign matter from pan Flush pan and drain tube with clear water 39 If drain tube is restricted it can generally be cleared by high pressure water Cut plastic line and work outside condensate pan and away from coil to clear drain tube NOTE There MUST be a trap in condensate line Trap must be at least 3 in deep not higher than the bottom of unit condensate drain opening and pitched downward to an open drain or sump 4 CAUTION Do not use caustic household drain cleaners in condensate pan or near coil Drain cleaners can quickly destroy coils BLOWER MOTOR AND WHEEL Clean blower motor and wheel when cooling coil is cleaned To clean or service wheel or motor proceed as follows 1 Pull unit disconnect when used and remove blower access panel 2 Disconnect motor electrical leads from control box and capacitor Mark location of wires for reassembly 3 Remove 3 bolts holding motor mount to blower housing while supporting motor shell with hand 4 Pull motor inlet ring and blower wheel assembly out of blower housing 5 With blower wheel inlet ring and motor mount still attached to mo
109. ted Controls and Motor ICM2 PCB Layout and Description Sequence of Operation Easy Select Configuration Taps Troubleshooting PCB Troubleshooting ICM2 Condensed Version of Troubleshooting FK4C Motor and Controls Accessories THERMOSTATIC EXPANSION VALVES Problems Affecting TXV PISTON BODY CLEANING OR REPLACEMENT LIQUID TUBE STRAINER COIL CONDENSATE PAN REMOVAL AND REPLACEMENT A Coil Units Slope Coil Units CARE AND 22222 222 2 95518 1 Filter Assembly Cooling Coil Drain Pan and Condensate Drain Blower Motor and Wheel FF1A FF1B FF1C SERVICE AND TROUBLESHOOTING ce 37 39 Fan Motor Electric Heater Service Cleaning or Replacing Refrigerant Flow Control Device Liquid Tube Strainer Sequence of Operation Care and Maintenance FD3A SERVICE AND TROUBLESHOOTING 39 42 Fan Motor Electric Heater Service Cleaning or Replacing Refrigerant Flow Control Device Liquid Tube Strainer Care and Maintenance FG3A SERVICE AND TROUBLESHOOTING 42 43 Service Maintenance FA4A AND FC4B SMART HEAT CIRCUIT BOARD FUNCTION AND TROUBLESHOOTING 43 48 PCB Component Layout Description and Function Unit Functions Smart Heat Operation Electrical
110. ted with dirt or lint vacuum it with a soft brush attachment Be careful not to bend coil fins If coil is coated with oil or grease clean it with a mild detergent and water solution Rinse coil thoroughly with clear water Be careful not to splash water on insulation Inspect drain pan and condensate drain at the same time cooling coil is checked Clean drain pan and condensate drain by removing any foreign matter from pan Flush pan and drain tube with clear water If drain tube is restricted it can generally be cleared by high pressure water Cut plastic line and work outside condensate pan and away from coil to clean drain tube A CAUTION Do not use caustic household drain cleaners in the condensate pan or near the coil Drain cleaners can quickly destroy a coil Step 3 Blower Motor and Wheel Clean blower motor and wheel when cooling coil is cleaned CAUTION Disconnect electrical power before removing any access panels To clean blower motor or blower wheel 1 2 Remove blower access panel Remove motor leads from PCB Note lead location for ease of reassembly Remove 2 outside screws holding blower motor assembly against blower deck flange and slide assembly out of cabinet Remove screw in strap holding motor capacitor to blower housing and slide capacitor out from under strap Remove screw with green wire from blower housing Mark blower wheel motor and motor support in relation to blowe
111. the PCB is wired correctly before the PCB has power applied to it IF THERE ARE BLOWN DIODES 1 If diodes a and b are blown it is probable the electric heater plug was miswired Correct the miswiring It should be noted the board will need to be replaced if the diode indicated is bad 8 820 6 89840 89 H3MOd ONIYIM AV T3H ONIYIM H3MOd AHOLOVH 09345 ONIYIM 1410 1913 O Qqavoa ADVLIOA Qv31NONINOO YOLOW yg 43385 SOAK a 2 O 9 99 1 S IVNIINH3 L YOLOW ddaSHIWH STIVNIINH3 L NOWWOONvd 485 HL 03545 OLON 12 1011002 Ajoede 1 6 6c0Z6V 1VLSIGINNH 1SH 89850 0 89 Ald H3MOd 1910 01315 7VNIWH3I 39vL OA 63 63 68 ale E 227 4 Qv31lNONINOO YOLOW 03545 OLON
112. tially open or closed position LIQUID TUBE STRAINER The TXV and refrigerant flow control device is protected on the indoor coil by a wire mesh strainer It is located inside the 3 8 in liquid tube at field braze joint just outside unit casing Access to strainer is through field braze joint COIL CONDENSATE REMOVAL AND REPLACEMENT Step 1 A Coil Units HORIZONTAL CONDENSATE PAN HORIZONTAL EXPANSION DEVICE TXV SHOWN COIL TOP SEAL DELTA PLATE SCREWS CAL CONDENSATE COIL BRACKET PAN DELTA PLATE TO 4 90268 30 A Coil Component Location If it is determined that system does not have leaks and refrigerant is not contaminated proceed as follows 1 Recover system refrigerant Attach manifold gage set to service valves Front seat close liquid tube service valve Start unit in cooling mode Run unit until vapor pressure reaches 5 psig 35kPa e Turn off electrical supply to outdoor unit f Front seat vapor service valve g Recover any remaining refrigerant NOTE All outdoor unit coils will hold only factory supplied amount of refrigerant Excess refrigerant such as in long tube applications may cause compressor internal pressure relief valve to open indicated by sudden rise in vapor pressure before vapor pressure reaches 5 psig 35kPa If this occurs turn off electrical supp
113. tor place motor on flat horizontal surface shaft up Mark position of wheel on motor shaft for reassembly 6 Loosen blower wheel setscrew and remove blower wheel from motor shaft NOTE Further disassembly of motor and mount is not necessary as adequate clearance is available to clean motor 7 Clean blower motor and wheel using a vacuum with a soft brush attachment Remove grease with a mild solvent such as hot water and detergent Be careful not to disturb balance weights clips on blower wheel vanes Do not drop or bend wheel as balance will be affected To reassemble unit proceed as follows 1 Place motor with mount attached on flat horizontal surface with shaft up 2 Set inlet ring on top of motor mount grommets Center inlet ring flush on all 3 grommets 3 Slide blower wheel onto motor shaft with setscrew upward and aligned with shaft flat portion Vertically position wheel along shaft to position marked during disassembly NOTE If previous shaft was not marked or if replacing previous motor set blower wheel position by sliding blower wheel along motor shaft to 1 1 8 in above rubber grommets See Fig 33 4 Hold blower wheel in place and carefully tighten setscrew 5 Position motor and blower wheel assembly to blower housing as originally oriented 6 Secure motor mount to blower housing using bolts previously removed 7 Attach green wire to blower housing with screw 8 Connect electrical and capacitor leads to
114. ugh diodes D1 D2 and D3 to motor W input HEAT PUMP HEATING MODE SINGLE SPEED OR 2 SPEED HIGH Thermostat closes circuit R to Y Y2 for single speed A circuit from R to 1 is also required for 2 speed high The Y Y2 signal is sent directly to ICM2 20 HEAT PUMP HEATING MODE TWO SPEED LOW Thermostat closes to Y1 The 1 signal is sent directly to ICM2 HEAT PUMP HEATING WITH AUXILIARY ELECTRIC HEAT Thermostat closes circuits to Y Y2 and or to Y1 with to W2 W3 or E and R to O in the case of defrost See previously described modes for circuit paths In the event that electric heating is called for by thermostat while heat pump is also operating in either heating or defrost mode electric heating signal will appear at motor connector pin 1 as described previously If necessary the motor will modify its airflow output to provide an airflow which is defined as safe for operation of electric heater CFM SELECT CONFIGURATION TAPS The CFM Select taps are used by installer to configure system The 2 is capable of discerning wave shapes on some of its inputs and uses this capability to modify its operation to a pre programmed table of airflows and can be modified in response to other inputs such as the need for de humidification ICM2 CONTROL POWER The ICM2 control power is supplied from R circuit through printed circuit runs to motor control connector pin 6 through motor control harness to motor The C si
115. ulation and adjustment 18 formed every 0 8 sec while motor is in operation There is no direct measure of static pressure but unit does react to a change in static to maintain constant airflow A change in pressure will result in a change in stator speed and torque The motor will begin to adjust on the next sampling caculate new desired speed and torque and adjust as necessary Step 9 Integrated Controls and Motor ICM2 An ICM is fed high voltage AC power through the 5 pin connector See Fig 22 The AC power is then rectified to DC by DO REMOVE OPTIONAL SAFETY GROUND DRAIN HOLE OPTIONAL SAFETY GROUND 1 6 9 5 POWER CONNECTOR 17112113114 15116 112133 41516 7 8 CONTROL CONNECTOR A94079 Fig 22 FK4C ICM2 Motor a diode module After rectification DC signal is electronically communicated and fed in sequential order to 3 stator windings The frequency of these commutation pulses determines motor speed The rotor is permanently magnetized An ICM is powered with high voltage at all times The motor will run with high voltage alone Low voltage must be applied to control plug to run motor Step 10 PCB Layout and Description NOTE Layout of actual PCB
116. ultipoise Modular FK4CNF 001 005 Multipoise Single Piece NOTE Multipoise units are approved for upflow downflow and horizontal left and right applications Table 2 Fan Motor Speed Taps UNIT NUMBER OF HIGH MEDIUM LOW MODEL SIZE SPEEDS SPEED SPEED SPEED COMMON FA4A 018 036 2 Black Blue Yellow FA4A 042 060 3 Black Blue Red Yellow FB4A 018 070 3 Black Blue Red Yellow FC4B 024 070 3 Black Blue Red Yellow FD3A 018 030 2 Black Red Yellow 1 1 1 018 030 2 024 036 048 060 1 4 001 004 3 Black Blue Red Yellow Belt drive 8 LOW oo 5 VOLTAGE PCB BLOCK WIRING cji RI R 54 gt x __ 9 2 et TET cs n R1 8 4 mM 2 C2 C1 5 S gt wo 7 5 wA i 1840061 97020 Fig 3 Fan Printed Circuit Board INDOOR FAN 2 Functional Control 1 Wiring a Thermostat and Relay Control Indoor fan motor yellow lead is wired to C terminal on transformer The red blue or black speed lead is wired to SPT terminal on fan relay part of PCB Units are factory wired on medium speed blue lead connected NOTE Unused fan speed leads must be capped or taped off to prevent direct short to cabinet surface When thermostat calls for the fan in cooling heat pump heating or f
117. under strap and tighten strap screw Slide blower assembly to blower deck Be sure once blower is within the unit casing to force blower assembly toward control box while sliding assembly into unit to ensure that blower assembly engages deck properly Fasten blower assembly to deck with screws previously removed Reconnect electrical leads to PCB Reconnect electrical power to unit and test fan for proper rotation 37 FF1A FF1B FF1C SERVICE AND TROUBLESHOOTING A WARNING Before installation or servicing system always turn off main power to system There may be more than 1 disconnect switch Turn off accessory heater power if applicable Elec trical shock can cause personal injury or death Step 1 Fan Motor The motor is 2 speed direct drive High speed lead is black low speed lead is red and common lead is violet Be sure proper blower speed has been selected For units with electrical heat low speed tap can be used For cooling use high speed tap The motor is turned on through 2 different routes The first occurs when thermostat calls for the fan in cooling heat pump or fan only mode A 24 vac signal is sent to relay causing relay to close its normally open contacts turning fan on The second occurs when there is a call for electric heat A 24 vac signal is sent to heater sequencer causing it to close directing 230v through the normally closed contact of fan relay turning fan on The fan remains on until
118. ut supplemental heat independent of outdoor thermostats Although PCB has provisions for an outdoor thermostat it is not needed for staging On cycle down indoor fan remains on 60 sec to recover heat stored in indoor coil DEFROST The Smart Heat PCB stages the correct amount of supplemental heat during defrost If too much heat is added system stays in defrost for completion of defrost cycle even though thermostat is satisfied On next cycle 1 less element is energized during next defrost period NOTE If 24 v power from thermostat is interrupted while unit is in defrost mode the default cycle will be completed before unit shuts down TROUBLESHOOTING PRINTED CIRCUIT BOARD DIAGNOSTIC LED The PCB of Smart Heat option heater package contains a micro processor which controls fan operation fan speed outdoor unit and heater elements For troubleshooting a service LED indicates condition of PCB See Table 11 for LED flash codes Step 4 Electrical Operating Sequences and Troubleshooting NOTE Refer to Table 12 for proper input and output voltages READY TO START In ready to start standby mode LED on board indicates a steady flash In this mode 24 v power should be available at control s low voltage terminal strip terminals R and C If 24v is not present across R and C check the following Is low voltage fuse on control board good Table 12 Troubleshooting Voltage Readings and Test Points Input Voltages
119. wires at pins 7 and 9 in 12 pin plug 3 Verify that there is a low voltage control signal to motor The motor receives its control signals through the 7 pin motor plug P2 The voltage output of each pin in plug will be different for each mode of operation Table 6 lists circuit board screw terminals that have 24 vac present powered by thermostat and lists voltage that is present at each pin of 7 pin plug for each operating mode Tests should be taken between points listed and common C screw terminal If all values of any 1 of operating modes checks OK and motor fails to run then motor is defective and should be replaced IF MOTOR DOES NOT RUN SMOOTHLY First verify that the cause is not an out of balance or damaged blower wheel If it is not blower wheel motor is defective and should be replaced IF MOTOR SHAFT DOES NOT ROTATE SMOOTHLY When manually turning shaft of ICM the shaft does not rotate smoothly The shaft has steps during rotation and is referred to as motor cogging The cogging is caused by permanent magnets passing each pole of motor However shaft should not require excessive force to turn If shaft is VERY difficult to turn motor control or bearings have failed and motor must be replaced IF MOTOR DOES NOT STOP RUNNING 1 Check for good ground between motor ground lead and transformer common lead 2 If motor continues to run remove all thermostat wires If motor stops replace circuit board 3 If motor c

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