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Bryant FA4A User's Manual

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1. Fi IVICIN CAUTION THIS COMPARTMENT MUST BE CLOSED EXCEPT FOR SERVICING NOT SUITABLE FOR USC ON SYSTE EXCREQNG BLOWER MOTOR 150V TO GROUND ROTATION ATTENTION BOKW 1 SCHEMATIC DIAGRAM LEGEND FIELD POWER WIRING DISCONNECT PER NEG CAPACITOR LB UMT SWITCH SEE MATING PLATE COM COMMON MARKED TERMINAL ml FOR VOLTS amp HERTZ 5 F LOWVOLTAGE FUSE X PLUG AND RECEPTACLE 5 fo GND FM FAN MOTOR FCA PRINTED CIRCUIT BOARD __ FIELD POWER WIRING SEQ SEQUENCER FR FAN RELAY TRAN TRANSFORMER FU LINE FUSE Q UNMARKED TERMINAL GHD EQUIPMENT GROUND RECP RECEPTACLE HVTB HIGH VOLTAGE TERMBLOCK CB CIRCUIT BREAKER MIR HEATER FIELD POWER WIRING EDDLING CONTROLONLY n 1 1 POWER WIRING Mas B nue 8 ur it 81 4 2ONSAVAC 24VAC 2 E 177 3 2 81 4 H RESP 30KW SPH SCHEMATIC DIAGRAM FIELD POWER WIRING DISCONNECT PER BARRIER SEE NOTE THERMOSTAT 1 USE COPPER WIRE 76 C MIN ONLY BETWEEN DISCONNECT SWITCH AND UNIT 2 TOBE WIRED IN ACCORDANCE WITH NEG AND LOCAL CODES TRANSFORMER PRIMARY LEADS BLUE 204V RED 230V 4 IF ANY OF THE ORIGINAL WIRE AS SUPPLIED MUST BE REPLACED UBE THE SAME OR EQUIVALENT TYPE WIRE amp REPLACE LOW VOLTAGE FUSE WITH NO GREATER THAN 5 FUBE 20KWHEATER USES ONE DOUBLE FOLE LG MIDDL
2. P sA 1 A G HP GOMFORT HP EFF PK AGHP TU aux wes i AGHP DELAY ONOFF Wan duin 250 Gh 1 M pau Fa y 1 BLU 7 O F i i on tof OCTET JWI 210 uU JN TRAN RED CI AUXI HUMI u BLK teu am COMMON vi 2660 i as INDOOR THERMOSTAT RECP RED 9 GEE NOTE 3 er TT Q SNEED rm RECP 3 Tx BEN _ ICM BE 101210970918 EGE EA JU ORN T 4 BUCS NOTES LEGEND 1 copper wire only between dlaconnact switch and unit 2 Connact Y to 7 C to C ete etc In pattern shown o MARKED TERMINAL 18 LIMIT SWITCH 8 Transformer primary leads V RED 230V UNMARKED TERMINAL ICM FAN MOTOR 4 be wired in accardandge proin and local codes amuan FIELD POWER WIRING TRAN TRANSFORMER 5 f any of the original wire suppllad must replaced use the same or 27577 PLUS AND RECEPTACLE EQUIPMENT GROUND equivalent type wire FU FUSE 6 Replace low volage fuse with no graatar than 5 amp fuse AD RM PUMPER RECEPTACLE 7 Fuse is wired in series between transformer SEC and low voltage circult CIRGUITBHEARER ROKW heater uses ana double pola LS
3. Belt drive 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 coi 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 WARNING Before installing or servicing fan coil always turn off all power to unit There may be more than 1 disconnect switch Tum off accessory heater power if applicable Electrical shock can cause personal injury or death A UNIT IDENTIFICATION The 16 position numbering chart allows identification of all available fan coil units See Fig 2 FB4A FCAB AND CIRCUIT BOARD FUNCTION AND TROUBLESHOOTING This section of the service manual describes the CESO130003 by examining the functional operation of the PCB compo nents 1 PRINTED CIRCUIT BOARD 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 side of transformer to indoor thermostat and outdoor section 2 A S amp fuse is used to protect the low voltage transformer sec
4. CHASSIS GROUND RED ORN OPTIONAL IFR TOR P cHassis VIO Pejam GROUND Der vo SCHEMATIC DIAGRAM FOR COOLING CONTROL RATING PLATE m IFR MOTOR MOTOR FOR VOLTS amp HZ BAND DISCONNECT 7 4 WA i 8 FIELD V Bis Seo ee 3 15 CHASSIS GROUND Deer heo WAY G CHASSIS GROUND 1 UNIT WIRED FOR 230v OPERATION USING 2 UNUSED TRANSFORMER LEADS MUST BETAPED 3 IF ANY OF THE ORIGINAL WIRE AS 4 FIELD WIRING USE COPPER CONDUCTORS ONLY 5 FAN RELAY 4 I8 A DEAD TERMINAL FOR Dor OPTIONAL IFR TDR COMPONENT ARRANGEMENT TRANS 24V BLK 208 230 BLU RED DISCONNECT HTR1 HTR2 D 5 zm WHEN EQUIPPED o s 8 05540 WHEN EQUIPPED d CHASSIS GROUND MOTOR SPEED SELECTION HI BLACK LOW RED COMMON VIO FIELD WIRE EU HEAT PKG SIZE RATING 2 4244 90 C 12 50 24 ar 7 5 KW 8 11 KW 90 COOLING 14 occ LEGEND O MARKED TERMINAL o UNMARKED TERMINAL 18 LIMIT SWITCH FR FAN RELAY IFR INDOOR FAN RELAY IFR TD INDOOR FAN RELAY TIME DELAY SEQ SEQUENCER CAP CAPACITOR HTR HEATER TRANS TRANSFORMER FIELD POWER WIRING OPTIONAL WIRING A FUSE CHASSIS GROUND NOTES BLACK AND RED TRANSRORMER PRIMARY LEADS FOR 26V OPERATION USE BLACK AND BLUE TR
5. gt rE wanoouuicgr3as j il al H if WP E if 2 AUG 14 2008 THU 03 45 PM UTC TECH PUB FAX No 317 240 5682 P 003 TABLE t PRODUCT OFFERING MODEL UNIT SIZE DESCRIPTION GABINET FA4ANF 018 060 Multipalaa Singla FB4ANB 042 070 Modular 018 060 Multipoise Single Piece FBAASB 042 060 eee Modular FB4ASF 018 060 m Single Piece FC4BNB 042 070 Multipoise Modular FCABNF 024 060 Multipolse Single Plece FD3ANA 018 030 Horizontal Single Fiece FFIA FFIBNA 018 030 Vartical Single Placa FG3ANA 024 036 048 060 Horizontal Small Commercial Single Piece FH4ANB 003 004 Multipolsa Modular FH4ANF 001 004 Multipoise Single Fiece FKaBNB 005 008 Multipoise Modular 001 004 Multipalse Single Place NOTE Mullipoise 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 042 060 3 Black Blue Red Yellow FB4A 018 070 a Black Blue Rad Yallow FC4B 024 070 3 Black Blue Red Yellow FD3A 018 030 2 Hed Yellow FFIA FFIB 018 030 2 Black Rad Violet 024 096 048 060 1 mx FH4A 001 004 a Black Blue Red Yellow
6. 50 Hz Ta Transformer line voltage connection 230 vac 60 Hz Transformer tap storage terminal for 208 vac lead Secondary sonnectlon from transformer 24 vac This connection is common to chassis ground through eyelet marked GROUND SCREW REQUIRED 9 250 X 0 038 SEC2 Secandary connection from transformer 24 vac HUMI Low voltage ground for humidifier option 24 vdc HUM2 Low voltage output for humidifier option 24 AUXI Low voltage ground for auxiliary option 24 AUX2 Low voltage output for auxiliary option 24 Mi sennectlon to Hower motor 0 187 X 0 032 Ti Common connection for transformer RED Common to screw terminal and SEC2 TABLE 4 CONNECTIONS ON SINGLE BARRIER STRIP MOUNTED CROSS SLOTTED CAPTIVE BINDING HEAD SCREW TERMINAL DESCRIPTION Gonnection for W2 signal from thermostat Connection for W3 signal from outdoor thermostat Connaction for E signal from thermostat Connection for Y signal from thermostat Connection for G signal from thermostat Gonnection for O signal from thermostat connection of this terminal with ventral clreiity This connection Is a flald termination for use in connecting L lines of thermostat and outdoor unit together Thare is no for low speed compressor operation Connection for R signal te tharmostat 24 vac Connection for C terminal to thermostat 24
7. BLOWER MOTOR AND WHEEL Clean blower motor and wheel when cooling coil is cleaned AUG 14 2008 THU 03 49 UTC TECH PUB CAUTION Disconnect electrical power before remov ing 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 case 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 blower 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 soft brush attachment Remove gtease with a mild solvent such as hot water and detergent Be careful not to disturb balance weights clips on blower Whee vanes Also do not drop or bend whee
8. 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 C Pulley and Belts Check belt tension and pulley alignment See Fig 21 Belt tension is adjusted by motor tailpiece bolt A deflection of about 3 4 in to 1 in per foot of span should be obtained by pressing belt gt AUG 14 2008 THU 03 51 UTC TECH PUB BLOWER MOTOR amp GROUND GROUND LEAD 91151 Fig 20 WlrIng Schematic 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 slong motor mounting bracket Adjust blower speed by loosening setscrew in 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 sctscrews and bolts MUST BE h PARALLEL Ye FOR PROPER 2 ALIGNMENT PULLEY ALIGNMENT BELT ADJUSTMENT 91150 Fig 21 Checking Pullay Alignment and Tightness D Cieaning or Replacing Refrigerant Flow Control Device Refer to Fig 19 and instructions given Service and Troubleshooting section above ll MAINTENANCE WARNING Disconnect electrical power to all c
9. 2 Inspect cooling coil drain pan and condensate drain cach cooling season for cleanliness Clean as necessary To be performed by trained personnel Inspect blower motor and wheel for cleanliness cach heating and cooling season Clean as necessary Inspect electrica connections for tightness and controls for proper operation each heating and cooling season Service 85 necessary NOTE Never operate without a filter or with hinged access door open Damage ta blower motor may result A Cooling Coll 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 before each cooling season If coi 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 ig checked Clean drain pan and condensate drain by removing any foreign matter from Flush pan and drain tube with clear water Clear drain line ifrestricted NOTE There MUST be a trap in condensate line Trap must be at Jeast 3 in deep not higher than the bottom of unit condensate drain opening and pitched downward to an open drain or sump B Blower Motor and
10. close liquid tube service valve c Start unit in cooling mode 5 d Run unit until vapor pressure reaches 5 35kPa e Tum off clectrical supply to outdoor unit f Front seat vapor service valve 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 reacties 5 psig 35kPa If this occurs t rn off electrical supply to outdoor unit immediately front seat vapor service valve and recover any temaining tefrigerant 2 Tum 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 Ifa torch is used to unbraze tube set protect fitting panel with wet cloth or braze shield as necessary 5 Remove coil access panel 6 Remove clip secuting fitting panel to condensate drain pan Remove fitting panel 7 Remove any shipping clips including horizontal pan clip and slide coi eondensate pan assembly out of unit 8 Upflow or Horizontal Applications Only Remove hori zontal condensate drain pan from coil condensate pan assembly See Fig 14 FAX No 317 240 5662 P 015 9 Remave 4 coil brackets See Fig 14 10 Remove screws at delta plates and remove c
11. 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 Replace seal ting on retainer Reconnect refrigerant tube to piston body 6 7 amp 9 10 Evacuate tubing and coil as necessary Pressurize tubing and coil then leak check CAUTION Use a backup wrench and do not over tighten as deformation of the piston body will occur causing the piston to lodge in a partially open or closed position LIQUID TUBE STRAINER The 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 ig through field braze joint COIL CONDENSATE PAN REMOVAL AND REPLACEMENT A COIL UNITS If it is determined that system does not have leaks and refrigerant is not contaminated proceed as follows 1 Recover system refrigerant AUG 14 2008 THU 03 48 UTC TECH PUB HORIZONTAL CONDENSATE PAN HORIZONTAL EXPANSION DEVICE SHOWN GOIL TOP SEAL DELTA PLATE VERTICAL CONDENSATE GOIL BRACKET PAN SCREWS PELTA PLATE TO PAN 4 PER UNIT 90268 Fig 14 A Coil Component Location a Attach manifold gage set to service valves b Front seat
12. e motor If transformer is receiving correct primary voltage 3 Check low voltage fuse shown in Fig 6 If fuse is blown but is not putting out correct secondary voltage transformer replace it The transformer cannot supply power to board needs to be replaced with fuse blown or loose If fuse blows when unit has power applied to it the system most likely has 1 of the following If Electric Heat Stages WHI Not Turn On But Fan problems Turn On a Check contro circuit for a short or miswiring problem 1 Check wiring of sequencers Pay particular attention to b The maximum Joad on transformer is 40 va If load on high and low voltage wiring of sequencers transformer is excessive the low voltage 5 amp fuse 2 Check plug wiring to sure that it is wired correctly will blow to protect transformer If load exceeds va rating of transformer a larger va tated transformer needs 3 Check voltage to sequencer Sequencer number 1 receives a fo be installed Check sequencers for excessive current 24 vac signal If it is receiving correct voltage check to see draw if sequencer is closing If sequencer is not closing but is 10 AUG 14 2008 THU 03 47 PM UTC TECH PUB TABLE 3 MALE FEMALE QU FAX No 317 240 5662 P 011 TERMINALS SIZE FEMALE SIZE MALE DESCRIPTION M2 Motor line voltage connectian 230
13. fuse may blow If a heater is miswired correct miswiring by comparing it to heater wiring label 4 Check connections on primary side of transformer If they are not connected properly the low voltage termina board cannot supply the 24 v signal to energize fan relay transformer is receiving correct primary voltage but is not putting out correct secondary voltage transformer needs to be replaced AUG 14 2008 THU 03 46 UTC TECH PUB B 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 PGB HAS HIGH VOLTAGE APPLIED TO IT 1 Check low voltage 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 transformer output is low less than 18 vac refer to items 3 and 4 of previous If PCB Has High Voltage Applied To Yt section IF TRACES ARE OVERHEATED ON BACK OF Usual
14. if it is opening and closing It may be stuck in the normally closed position due to debris in relay E Transformer Failure 1 Check 208 v and 230 v transformer connections They may be miswired ELECTRIC HEATER FUNCTION AND TROUBLESHOOTING This section describes KEA and KFB series electric heaters by examining the functional operation of these beaters L DESCRIPTION OF ELECTRIC HEATER COMPONENTS A 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 FAX No 317 240 5662 006 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 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 current switch When system temperatures cool sufficiently the switch will automatically teset to its closed position Normal failure mode for this switch is open Jf 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
15. is required by local cades i Y terminal provides output from control board 10 energize outdoor heat pump contactor 2 Jumper wires TW1 and TW2 See Fig 22 TW connects W2T to W3 to limit staging of electric heat with use of an outdoor thermostat See Table 7 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 in efficiency mode With JW2 cut thers is no loss of performance due to reduced indoor blower speed when heat pump is oper ating near balance point This jumper may need to be cut if selected cooling fan speed is the same as required minimum motor LO speed tap selection With JW2 cut fan terminal LO becomes dummy terminal O AUG 14 2008 THU 03 51 UTC TECH PUB a 130121 01 FAX No 317 240 5682 025 LOW VOLTAGE TERMINAL BOARD CUT WHEN OUTDOOR THERMOSTAT 3 fuse is used to protect low voltage transformer and 4 AUX and AUX are connections for airconditioning accessories EAC humidifier etc 5 F2 and LO are connections for indoor fan 6 The 9 pin receptacle connects heater package wiring har ness 7 SEC and SEC2 are used to connect secondary side of transformer to SECI is
16. 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 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 with clear water Be careful not to splash water onto insulation 20 FAX No 317 240 5662 P 020 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 drain tube is restricted it generally be cleared by high pressure water Cut plastic line and work outside condensate pen and away from coil to clear drain tube NOTE There MUST be a trap in condensate line Trap must be at least 2 1 deep not higher than the bottom of unit condensate drain opening and pitched downward to an open drain or sump CAUTION Do not use caustic household drain cleaners in condensate pan of near coil Drain cleaners cen quickly destroy coils C Blower Motor and Wheel Clean blower motor and svhee 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 rea
17. specd direct drive High speed lead is black CLEANING OR REPLACING REFRIGERANT FLOW low speed lead is red and common lead is yellow CONTROL DEVICE NOTE Unused fan speed leads must be tapped off to prevent 1 Pump down outdoor unit Close service valves at outdoor direct short to cabinet surface unit The motor 18 tumed on through 2 different routes The first occurs CAUTION Damage may occur to the seroll compressor if operated at a negative suction pressure during a system fan only mode A 24 vac signal is sent to relay causing relay to pumpdown close its normally open contacts turning fan The second occurs when there is a call for electric heat 24 vac signal is sent to heater sequencer causing it fo close directing 230v through the hormally clased contact of fan relay turning fam on The fan n 4 qa on sequencer opens Refer to FD3A typical wiring 2 and if possible recover remaining refrigerant from diagram shown in Fig 18 tubing and coil through gage port om vapor tube service i ELECTRIC HEATER SERVICE 5 Service can be completed with heater in place Shut off power 3 Disconnect liquid refrigerant tube from refrigerant flow before servicing E 2 control device Refer to Fig 19 valve A Limit Switch 4 Remove refrigerant flow control device piston retainer Mun Avoid damaging O ring or machined surfaces on piston Malfunction prevents heating element from co
18. stages tieat up to maximum level if signal is energized for proper amount of time 6 IF Orly W3 is energized there is no effect on No heat ig energized is energized The accessory kit KEAIROIDIACR is used to connect an or humidifier NOTE Loads cannot be connected directly to AUX and AUX Use the specified kit only D Bl wer 1 Blower On Delay To optimize comfort there is a 30 sec blower on delay in heat pump heating mode only TABLE 7 ELECTRIC HEATER STAGE LIMITING HEATER PART NO STAGES KW OPERATING WeT Only JW1 cut WET and Wa Heater Stage KFAEH2201H10 10 kw Non Fused KFAEH2301H15 15 kw Fused KFAEH2401H20 20 kw Fused 25 AUG 14 2008 THU 03 51 UTC TECH PUB 2 Blower Off Delay Smart Heat control uses a 60 sec off blower delay as opposed to the standard 90 sec delay SMART HEAT OPERATION A Cooling The Smart Heat option controls cooling mode in same manner ag conventional heat pumps are controlled The fan has a 90 sec delay off on cycle down B Heat Pump Heating The Smart Heat option docs not control heating in the conventional method The PCB enetgizes compressor 30 sec before indoor fan is energized This allows indoor coil to heat up eliminating cold biow 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
19. the fan speed 27 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 toom 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 sec how many stages of cloctric heat are energized at a given time and confirm operation of sequencer using a voltmeter If quick check of all stages is desired set room thermostat as high as it will go With constant signal on W2T terminal sequencers energize every 10 minutes until alll heaters are on The previous paragraphs described how to check for low voltage inputs to contro by placing voltmeter Jeads across low voltage terminal strip and checking for 24v The call for electric heat be confirmed by placing voltmeter leads across W2T and C To check for operation of sequeticers Gheck directly across appropriate sequencer coil for 24 volts DC NOTE All sequencer coils are powered by 24 volts DC This voltage 15 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 va
20. 82 MOUNT FLUSH WITH THESE TWO EDGES 93216 Fig 10 Mounting KFAIROTOTACR Relay Kit FK4B 110 VAC BRANCH CKT AUX1 AUX2 GND HOT NEUT 4 x in GAN VDC RELAY 9 217 Fig 11 KFAIROTOTACR Relay Wiring Schematic HUMIDISTAT HUMIDISTAT WIRING FOR DE HUMIDIFY MODE RED WIRE FROM IGM2 MOTOR TO PCB TERMINAL MARKED RED 93215 12 Humidistat Wiring for De Humidify Made 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 telay must be installed on single phase reciprocating compressors to boost torque to compressor motor so it may overcome the unequalized system pressures AUG 14 2008 THU 03 48 PM UTC TECH PUB The standard is a bi flow metering device that is used in condensing and heat pump systems to adjust to changing load conditions by maintaining a preset superheat temperature at outlet of evaporator coil The volume of refrigerant metered through valve scat 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 con verted into pressure pushing downward on the diaphragm which opens the valve via push rods 2 The suction pressure at outlet of evaporator coil is trans fered via the external equalizer
21. ANSFORMER PRIMARY LEADS AND LOOPED SUPPLIED MUST BE REPLACED USE THE SAME OR EQUIVALENT WIRE UNUSED MOTOR LEAD STORAGE TO GHANGE MOTOR SPEEDS EXCHANGE THE BLACK AND RED MOTOR LEADS ON THE FAN RELAY 316596 401 REV B A911409 Fig 168 FF1A FF1B Typical Unit Wiring Label i9 AUG 14 2008 THU 03 50 UTC TECH PUB 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 B Heat Pump COOLING On a call for cooling the thermostat makes circuits R O R Y and R G Circuit 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 ni tors HEATING a cali 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 throngh second stage room thermostat bulb Circuit R W energizes a sequence
22. AUG 14 2008 THU 03 45 lt Care and Maintenance d UTC TECH PUB Service Manual FAN COIL UNITS INTRODUCTION UNIT IDENTIFICATION PRODUCT OFFERING FAN MOTOR SPEED TABS FA4A FB4A FCAB AND FH4A CIRCUIT BOARD FUNCTION TROUBLESHOOTIN G Printed Circoit Board Component Unit Functions 235 EET Troubleshooting ELECTRIC HEATER FUNCTION AND TROUBLESHOOTIN Description of Electric Heater Components Troubleshooting KFA and KFB Series Electric Heaters 4 FAN COIL DESCRIPTION den AND TROUBLESHOOTING Integrated Controls and Motor ICM2 PCB Layout and Description of Operation E V Easy Select Configuration Taps Troubleshooting PCB Troubleshooting ICM2 Condensed Version of Troubleshooting Motor and Controls Accessories THERMOSTATIC EXPANSION VALY TXF sse 15 Problems Affecting TXV PISTON BODY CLEANING REFL CEMENT LIQUID TUBE STRAINER COIL CONDENSATE PAN REMOV AND REPLACEMENT A Coil Units Slope Coil Units CARE AND MAINTENANCE Filter Assembly Cooling Coil Drain Pan and Condensat Drain Blower Motor and Wheel i SERVICE AND TROUBLESHOOTING s 18 21 Fan Motor Electric Heater Service Cleaning or Repladiig Refrigerant Flow Control Device Liquid Tube Strainer Sequence of Operation E F
23. AX No 317 240 5662 throttled valve decreases indoor pressure drop which in tum increases refrigerant flow rate decreases overall defrost time and enhances defrost efficiency 1 PROBLEMS AFFECTING TXV A Low Suction Pressure 1 Restriction in TX V 2 Low refrigerant charge 3 Low indoor load 4 Low evaporator airflow B High Suction Pressure 1 Overcharging 2 Sensing bulb not secure to vapor tube 3 High indoor load 4 Large evaporator face area When installing or removing wrap with a wet cloth When teattaching TX V make sure sensing bulb is in good thermal contact with suction tube PISTON BODY CLEANING OR REPLACEMENT A CAUTION Do not vent refrigerant to atmosphere Re cover during system repair or final unit disposal P 015 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 vapor tube service valve 3 Disconnect refrigerant liquid tube from piston body See Fig 13 4 Avoid damaging seal ring or machined surfaces on piston bore and retainer 5 Using small wire with amp hook on end of it remove piston from body TEFLON SEAL Li PISTON LM BRASS RETAINER HEX BODY BRASS HEX NUT 93580 Fig 13 Rafrigerant
24. D Fan Relay Malfunction causes unit fan not to rum or run continuously Replace relay CLEANING OR REPLACING REFRIGERANT FLOW CONTROL DEVICE Refer to Fig 13 and instructions given in Piston Body Cleaning or Replacement section above IV 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 5 V SEQUENCE OF OPERATION Refer to Fig 16 A 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 nonmally open contacts close causing blower to operate The circuit between R and Y is also complete This completed circuit causes contactor in outdoor unit to close which starts compressor and outdoor fan AUG 14 2008 THU 03 49 UTC TECH PUB FAX No 317 240 5662 P 013 SCHEMATIC DIAGRAM FOR 2 8 amp 5 KW HEATERS BLK IFA TDA OPTIONAL MOTOR CAP RATING PLATE FOR VOLTS amp HZ DISCONNECT FIELD POWER SUPPLY CHASSIS CHASSIS VIO Aegan ape OPTIONAL IFR TDR 222 t p o7 SCHEMATIC DIAGRAM 7 5 amp 11 KW HEATERS SEE RATING PLATE FA UDR OPTIONAL MOTOR FOR VOLTS amp HZ BLK ioc un
25. D3A SERVICE AND TROUBLESHOOTING 21 23 Fan Motor Electric Heater Service Cleaning or Replacing Refrigerant Flow Control Device Liquid Tube Strainer Care and Maintenance SERVICE AND TROUBLESHOOTING Service Maintenance FAX No 317 240 5682 P 001 Gancels 03 1 b 1 1 95 8 A820 Fig 1 Typical Fan Coll PCB Component Layout Description and Function Unit Functions Smart Heat Operation Electrical Operating Sequences and Troubleshooting a SAFETY CONSIDERATIONS installation adjustment alteration service maintenance usc cap cause explosion fire electrical shock or other conditions which may cause personal injury or property damage Consult qualified installer service agency or your distributor ox for information or assistance The qualified installer 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 brazimg operations Have fire extinguisher available R ad these instructions thoroughly and follow all warnings or cautions attached to the unit Consult local building and National Electrical Cade NEC for special installation requirements It is importa
26. E TOP ELEMENT 7 B 18 24 AND 30KW HEATERS USE DOUBLE POLE LIMIT SWITCHES COMPONENTS 8 1 PHASE HEATERS ARE SHOWN WIRED FOR SINGLE SUPPLY CIRCUIT 10 USE ED AMP CLASS K FUSES ONLY FOR REPLACEMENT 44 8 SPEED MOTOR SHOWN OPTIONAL 2 SPEED MOTOR USES HI BLK AND LOW BLU OR RED 12 CONNECT A TO A G TO G SEE OUTDOOR INSTRUCTION FOR DETAILS 12 IF WIRE CRIMP 15 REMOVED AN EMERDENCY HEAT RELAY IG REQUIRED SEE OUTDOOR THERMOBTAT INSTRUCTIONS UNIT LARGEST HEATERS ARE SHOWN SMALLER HEATERS WILL HAVE FEWER ELEMENTS AND Y Y 321214 101 REV HVTE SEE RATING PLATE FOA VOLTS amp HERTZ 1 1 Bager i 6 3 27 24VAC A94346 Fig 4 Wiring Diagram 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 applied to it the system most likely has 1 of the following problems Check all 24 v wiring for an electrical short b The maximum load on transformer is 40 va If Joad on transformer is excessive the low voltage 5 amp fuse will blow to protect transformer Jf load exceeds va rating of transformer a Jarger va rated transformer needs to be installed Check sequencers for excessive current draw Check wiring of heaters a heater is miswired
27. GE FUSE WITH NO GREATER THAN MINIMUM MOTOR LO SPEED SELECTION FAN MOTOR THERMALLY PROTECTED LED FLASH CODES NOTE 3 NO POWER OR NOLIGHT OR FLASH PA NOTES STEADY LIGHT BOARD FAILURE 1 USE COFFER WIRE 750 MIN ONLY BETWEEN INDOOR THERMOSTAT DISCONNECT SWITCH AND UNIT BEE NOTES 2 LAND 8 STANDBY CONDITION 2 CONNECT LOW VOLTAGE WIRING A8 SHOWN 24VAC 3 GONNEUT TRANSFORMER PRIMARY THE PROPER LEGEND VEDI HEAT F un HEAT VOLTAGE TERMINAL 4 TOBE WIRED IN ACCORDANCE WITH NEC AND LOCALCODES UAGNOSTICUIGHT AA T a ASHES HEAT PUMP PLUS 5 OF THE ORIGINAL WIRE SUPPLIED MUST MM MOT FU LVB LOW VOLT TERM BAD 1 SEQUENGER VAL TYRE WIRE 8l SEQUENCER HEAT PUMP PLUS REPLACED USE THE SAME EQUIVALENT FAN MOTOR EQ FIELD LOW VOLTAGE 5 AMP FUSE GND EQUIPMENT GROUND 7 REFER TO THERMOSTAT INSTRUCTIONS FORE JUMPER HPLV HEAT PUMP LOW VOLT INSTALLATION HEATER 8 DO NOT CONNECT THERMOSTAT E TO PCB Wi LS LIMIT EWITCH TRAN TRANSFORMER XFORM THAN TERMINALS MARKED TERMINAL HEAT PLUS 3 SEQUENCERS MODE DEFROST MODE 5 FLASHES LEADS FAN SIZE 030 033 098 038 042 548 1060 070 PCBJUMPER JW ENSIS EMERSENGYHEAT M
28. IDDEN SGREW TO CASING DISTRIBUTOR TUBE EXPANSION DEVICE PISTON HOWN PAN TO COIL LIQUID TUBE FIELD CONNECTION COLUMN CONDENSATE PAN 90269 Fig 15 Slope Coll Component Locatlon If it is determined that system does not have leaks and refrigerant is not contaminated proceed as follows 1 Recover system refrigerant AUG 14 2008 THU 03 49 UTC TECH PUB Attach manifold gage set to service valves b Front seat close liquid tube service valve Start unit in cooling mode d Run unit until vapor pressure reaches 5 psig 35kPa Turn off electrical supply to outdoor unit f Front seat vapor service valve g Recover any remaining refrigerant NOTE outdoor unit coils will hold only factory supplied amount of refrigerant Excess refrigerant such as im 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 supply to outdoor unit immediately front seat vapor service valve and recover any remaining refrigerant 2 Tum 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 Ifa torch is used to unbraze line set protect fitting panel wi
29. OTOR SPEED AT 20 KW EDME LO LO LO gp UNMARKED TERMINAL MODE Fig 23 Smart Heat Typical Wirlng Diagram Motor Speed at 20kw Shown 29 P 023 4132 AUG 14 2008 THU 03 52 UTC TECH PUB FAX No 317 240 5662 030 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 ourfabs mean increased confidence that really pays dividends in faster troubleshooting fewer pum callbacks Course descriptions and schedules are in our catalog CALL FOR FREE CATALOG 1 800 962 9212 dv Packaged Service Training Classroom S rvice Training A894328 1935 Co P O Box 7D Indianapolis IN 46206 Printed In U S A 30 14072 Catalog 92 33 416
30. 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 veroil motor Plug hole securely 30 that ail does not drip when hinged access panel is lowered t 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 vanes Do not drop or bend wheel as balance will be affected FG3A SERVICE AND TROUBLESHOOTING L SERVICE A A Motor Ball bearing oilers are provided on blower motor Use eleciric motor oil or 10 er 20 nondetergent oil Check motor mount bracket and f Tighten ag required B Blower ay 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 20 for diagram of internal wiring for blower coil assembly Control box standard 4 in junction box is mounted on refrigerant contiection side of unit
31. a DISCONNECT PER N E C TRANS Bd aj gem gt R 3 WIRING I LEGEND NOTES Sonia eia e 1 TRANSFORMER PIGTAILS FIELD POWER WIRING 7 OPTIONAL 7 BLUE 208V RED 280V INSULATE FIELD GROUND WII FELD CONTROL FAN MOTOR PIGTAILS RED LOW XA FIELD SPLICE WIRE SLEEVE BLAGK HIGH INSULATE UNUSED JUNCTION LEAD CONNECTION 3 FAN MOTOR THERMALLY o UNMARKED CONNECTION PROTECTED FC CAPACITOR 4 SUITABLE FOR USE WITH COPPER FAN BELAY OR GOPPER CLAD ALUMINUM HTA HEATER CONDUCTORS AATED FOR 75 IFM INDOOR FAN MOTOR MINIMUM FOR COPPER USE 6 LS LIMIT SWITGH AWG FOR COPPER CLAD QT QUAD TERMINAL ALUMINUM USE 4 AWG SEQ SEQUENCER 4000500784 REV C 494378 Fig 18 FD3A Typical Wiring Diagram 2 AUG 14 2008 THU 03 50 THHEAD PROTECTOR RUBBEH PISTON 4 BODY O RING p CO UTC TECH PUB FISTON 92219 Fig 19 Refrigerant Flow Control Device For FD3A and FG3A CAUTION Use a backup wrench and do not over tighten as deformation of refrigerant flow control device body will occur causing piston to lodge 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 co
32. al injury or death L 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 biower speed has been selected For units with clectrical heat Jow 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 mods 24 vac signal is sent to relay causing relay to close its normally opem contacts turning fan on The second occurs When there is a call for electric heat A 24 vac signal 18 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 FFLA FFIB typical wiring diagrem shown in Fig 16 TE 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 ELECTRIC HEATER SERVICE Service can be completed with heater in place Shut off power before servicing A Limit Switch Malfunction preverts heating element from coming on Replace switch if malfunction occurs B Sequencer Malfunction causes heater not to come on or never shut off Replace sequenc r Transtormer A 40 transformer supplies 24 v power for contro circuit Replace transformer if faulty NOTE Transformer is fused Do not short circuit
33. are typically color coded to identify their range B 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 contro signal is removed In simplistic terms the sequencers which we use 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 RTC heat is supplied to a bimetallic disc which snaps through and closes switch The time required for PTC to heat to sufficient point controls ON timing of device The time required for disc to coo 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 cycle Higher ambicnt temperature means shorter ON times and longer OFF times These sequencers may be ganged up ta 3 on a common mounting plate to control up to 6 heater elements In this situation PTCs are different in each sequencer to provide a staged QN of a minimum of 10 sec between each sequencer 3 stages of 2 elements since the KPA and KFB series heaters use sequeiters in whi
34. ashes Gaol Moda Defrost Mode 5 Flashes Y O 6 Flashes Y W2D and or W2T 7 Flashes WeT Emergency Heat Mode IV ELECTRICAL OPERATING SEQUENCES AND TROUBLESHOOTING NOTE Refer to Table 9 for proper input and output voltages A 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 and If 24v is not present across R and C check the following B FAX No 317 240 5662 026 Js low voltage fuse on control board good Are line voltage fuses and FU2 good Is LED on control on steadily or not on at all Both of these indications signal possible board failure Is 208 230 v power available to control across pins 7 and 9 of 9 pin connector Is connection to board tight B Contlnuous Fan On call for continvous fan thermostat provides a 24 v input signal to G termina on low voltage terminal strip Sensing this signal the microprocessor energizes a telay 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 cont
35. ation See Fig The FK4B Fan Coil must be configured to operate properly with system components with which it is installed To successfully configure a basic system sec information printed on circuit board located next to select pins move the 5 select wires to pins which match components used A 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 range of heaters for which airflow also marked i approved The heater installed must fall within 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 AUG 14 2008 THU 03 47 PM o Q electric heaters are energized the ICM2 will run the higher t bm pump efficiency airflow and electric heater airflow The factory selection is largest heater range approved See Fig B 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 opera
36. be performed on this equipment 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 317 240 5662 P 017 WARNING Disconnect all power to the unit before servicing the field wires ox 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 gt The minimum maintenance requirements for this equipment are as follows 1 Inspect and clean or replace ait filter each month or required 2 Inspect cooling coil drain pan and condensate drain each cooling season for cleanliness Clean as necessary An inspection port is provided on all delta plates Remove plastic plug to inspect Replace plug after inspect tion 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 WARNING with any mechanical equipment per sonal injury can result from sharp metal edges Be careful When removing parts i FILTER ASSEMBLY To clean or replace air filter push plastic connecto
37. ber 1 closes first stage of electric heat ig energized In straight electric heat fan is also energized through the normally closed contacts 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 delay of 60 to 90 When sequencer opens first stage of heat tutus off along with fan providing thermostat is not calling for the fan 2 W3 When a signa is sent to W3 a 24 vac signal to sequencer number 2 causes sequencer to close with second stage of electric heat tuming on after short delay The 24 vac FAX No 317 240 5662 004 BLOCK WIRING LOW VOLTAGE FUSE AB4345 signal applied to sequencer number Timing is such that sequencer n mib r T will tarn before sequencer number 2 When signal to Wi7is off sequencer number 2 opens it 21 satisfied first stage of electric heat and far will also turn off providing thermostat is not calling for the fan When thermostat sends a signal to E 24 vai signal is sent to sequencer n mber 3 The 242767 applied to sequencer number 3 turns on third stage of slectric heat The 24 vac signal applied to sequencer number 1 turns on first stage of electric beat arid fan f calling for electric heat the signal are turned off nd sb
38. ch both switches of the 2 pole sequencer close simultaneously Older models used sequencers which had a minimum delay of 10 sec between cach 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 until the last heater de energizes Positive Temperature Coefficient PTC The PTC heater is essentially a resistor It will operate on cither AC or DC voltages It should be noted that hecause resistance of PTC increases it heats initial current inrush 18 higher than its steady state condition TROUBLESHOOTING KFA AND KFB SERIES ELECTRIC HEATERS A Discolored Wire Insulation at Terminal Check quick connect terminal at discoloration Connection may be loose creating a high resistance through connection point H Fuse Failure 1 Check for shorted wire Replace wite Never try to fix wire using electrical tape 2 Check shorted element If clement is shorted replace heater C No Heat 1 Check fuse for failure If fuse has failed refer to Fuse Failure section AUG 14 2008 THU 03 46 Q UTC TECH PUB 2 Check for faulty transformer Check output voltage of transformer 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
39. connected to equipment ground UNIT FUNCTIONS A Transformer NOTE Terminsls T if used and T3 are wired to primary or high side of transformer The 208 v terminal for blue v transformer Has primary leads is used on 13 For 2085 tions The 230 v terminal ir wife is for 230 applications T2 is a dummy terminal E wd ced B Electric Heat NOTE When troubleshooting elements position thermostat fo emergency heat Wait approximately 12 minutes for all clements to come on 1 When thermostat calls for electric heat a 24 V signal is sent to through W2T The PCB energizes first stage of electric heat Fig 22 Smart Heat Printed Circuit Board PCB 18 USED HIGH FAN ONLY WHEN CUT HEGEPTACLE CLIP 0130025 Ag4127 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 enerpized electric heat stages down in minute steps with the exception of first step The first step will be on only half as long as it was prior to WZT de energizing TM 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 7 5 When both W3 and W2T are energized without being cut or with outdoor thermostat closed system operation
40. e Wire Type Orange Wire AC HP Adjust Black Wire AC HP Time Delay Grey Wire SEQUENCE OF OPERATION A 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 Y1 is also required for 2 speed high The Y Y2 signal is sent directly to ICM2 C Cooling Mode Two Speed Low Thermostat closes circuits R to Y1 and R to heat pump only The Y1 signal is sent directly to ICM2 D Electric Heat Heating Mode Thermostat closes circuit R to W2 W3 or E The terminal block positions W2 W3 and E arc 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 through diodes D1 D2 and D3 to motor W input Heat Pump Heating Mode Single Speed or 2 Speed High Thermostat closes circuit to Y Y2 for single speed A circuit from R to 1 is also required for Z speed high The Y Y2 signal js sent directly to ICM2 F Heat Pump Heating Mode Two Speed Low Thermostat closes R to 1 The 1 signal is se
41. gh Speed Heating R Y Y2 Yi 0 24 vac 0 0 24 vac Continuous Fan H G 24 vac 0 0 24 vac Pin 1 24 vde with or without jumpers when ever any Individual heater input any combination of heater inputs are energized C If PCB Fuse Keeps Blowlng 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 voltage circuit or a direct secondary short When there i high current drawn on transformer it is most likely because transformer has been shorted or system is trying to draw mote 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 6 and 8 Be sure transformer is not shorting out because thermo stat wires are miswired 2 Check wiring of sequencers See Fig 6 and 8 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 TROUBLESHOOTING 2 FAN MOTOR A M Motor Does Not Run 1 With power turned off check all plugs and receptacles on circuit board and at mo
42. in fan goil In this mode toom thermostat at 1 provides an emergency heat input signal to smart edntrol at terminal WZT If jumper TWi at 2 has not been and an outdoor thermostat installed to control electric heat stages that same input signal is applied to terminals W3 For this example assume that jamper JW1 has not been cut Eventually the total number of heaters is cycled on In emergency heat mode LED indicator signals 7 flashes The amount of emergency heat available depends on whether jumper JW1 is cut and the number of heatirig elements Table 10 illustrates results under various conditions The heaters cycle on every 5 minutes unti maximum level is reached 18 FAX No 317 240 5682 028 TABLE 10 EFFECT OF JW1 ON EMERGENCY HEAT JW1 cut 4 glements 3 elements 50 68 7 JWH not cut 4 elements 3 elements 10095 100 Outdoor thermostat opens With JW1 cut outdoor thermostat f closed could cycle on additional heaters and system would perform as if JW1 was not cut In effect closed outdoor thermostat replaces cut jumper H Defrost In defrost mode LED indicat r signals 6 flashes Defrost is initiated by heat pump and is signalled to smart contro 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 pr
43. in the 12 pin plug Check for 24 between SECI and SEC2 If no voltage is present check the transformer Check for burn traces ot burnt components If bum spots present replace board AUG 14 2008 THU 03 48 UTC TECH PUB ROOM THERMOSTAT Remove thermostat wires from the circuit board Jumper screw terminals 1 at a time R G R Y Y2 R Y1 and R W2 If motor runs in all cases thermostat is bad Replace thermostat If motor does not run or runs in some eases but not in others continue by checking the wiring harness 4 WIRING HARNESS Shut off power to unit Remove 5 pin plug from motor 1 Remove 16 plug from motor Replace 5 pin plug and turn on power Check for 24v between pin 1 and pjn 12 on the 16 pin plug If no voltage is pr sent replace wiring fires See Fig 9 If voltage is present jumper screw terminal R Y Y2 on circuit board and check for 24v between pin 12 and pin 14 on 16 pin plug See Fig 9 If no voltage is present replace hamicss If 24y is present the motor is bad Replace motor CAUTION Never remove 5 pin high voltage plug from the motor with the power on 18 PIN PLUG 94375 Fig 9 Wiring Harness 16 Pin Plug VII ACCESSORIES A Electronic Air Cleaner EAC Familiar 230 vac EAC control power signal 1 and is not available because the 2 blower moto
44. ior to defrost smart control energizes sufficient elements to temper If heaters were enetgized 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 abtdss low voltage terminals W2D and C If 24v is not observed check the following 15 24v available across and 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 AUG 14 2008 THU 03 52 PM UTC TECH PUB FAX No 317 240 5662 isi HYR LK Se re i YEL YEL CAUTION C THIS COMPARTMENT MUST BE CLOSED EXCEPT FOR SERVICING DEREN Gavan ore eae BLOWER MOTOR 180v TO GROUND ROTATION ATTENTION CONVIENT FAS AUX INSTALLATIONS DE PLUS DE 150 Y ALA TERRE FIELD POWER WIRING DISCONNECT PER NEG BEE RATING PLATE a FOR VOLTS amp HERTZ 4 SEENOTE ft SEQ ETIN e E BiB 3 n SYSTEM TRANSFORMER 40 0 FERA i as FAN COILIHEATER 283VA PTS REMAINING AVAILABLE 13 7 V RED 5 EH PCB 208v T Ostet v Vw Osee REPLAGE LOW VOLTA
45. ircuits A before servicing unit Failure to do so may result in personal injury from electrical shock or moving parts WARNING As with any mechanical equipment per sonal injury can result from sharp metal edges Be careful when removing parts A Return Air 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 4 FAX No 317 240 5682 P 024 B Coil Drain Pan and Condensate Draln The coil 15 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 Be careful not to bend fins If coil is coated with oil or grease it may be cleaned with mild detergent and water solution Ringe 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 mest and holes Flush pan and drain tube with clear water Yf drain is restricted c
46. l as balance will be affected To reassemble blower 1 10 Place blower wheel back into housing Be stre 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 16 grounded to blower Housing Locate blower wheel setscrew over flat on motor shaft Rotate wheel in housing It should not mb 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 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 j 18 FAX No 317 240 5682 P 018 FF1A FF1B SERVICE AND TROUBLESHOOTING WARNING Before installation or servicing system always turn off main power to system There may be more than 1 disconnect switch Turn off accessory beater power if applicable Electrical shock can cause person
47. l Printed Circuit Board 2 Functional Control Thermostat and Relay Control When thermostat calls for the fan in cooling heat pump heating or fan only mode a 24 vde 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 15 turned off and relay opens causing fan to turn off after a 90 5 fan olf 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 C Electric Heat When thermostat calls for electric heat a 24 vac signal is sent to through W2 causing first stage to turn W3 and also receive signal if wired in with W2 The signal sent to W2 causes first stage to tum on If W3 and E are not wired to W2 the sequencers can be controlled individually to stage additional electric heat The sequence contro is described in the following section 1 W2 When thermostat sends a signal to W2 24 vac signal is applied across sequencer number 1 causing it to clase after a short delay When sequencer num
48. lean 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 GAUTION Disconnect electrical power before remov ing any access panels or electrical shock may result FB4A AND FC4B SMART HEAT CIRCUIT BOARD FUNCTION AND TROUBLESHOOTING PCB COMPONENT 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 2 R terminal is used to connect secondary side of trans former to thermostat and outdoor unit R is fused b C terminal 18 used to connect transformer secondary common for thermostat and outdoor unit Y terminal provides input signal from thermostat signal ing heat pump operation d G terminal provides input signal from thermostat signal ing Contiiiudus fari operation c O terminal provides input and junction terminal for reversing valve signal f W2D termina provides input from outdoor unit heat pump signaling control board that heat pump is in defrost W2T terminal provides input from thermostat signaling for supplemental or emergency heat W3 terminal provides input from outdoor thermostat W3 and W2T are factory connected by This input is used only if an outdoor thermostat
49. ls Y and The readings should be 24 If 24v is not available check the following Is 24v available across and C See Ready To Start section for items to chedk if 24v is not available Is 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 _ alsa be running at this time If indoor fan is not running refer to Continuous Fan section foritems to check When room thermostat is satisfied indoor fan continues to run an additional 60 sec to recover heat remaining in indoor coil E Heating Compressor and Electric Heat If heat pump alone cannot satisfy heat requirements of structure Toom thermostat calls for additional heat by way of an input to W2 terminal of contro When this occurs contral begins sequencing on electric heaters by energizing the first sequencer Indoor fan should be running at this time 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 aro 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
50. lts 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 docs not tell which ones are Is 9 pin connector for heater package tightly secured to control board AUG 14 2008 THU 03 52 UTC TECH PUB F Checking Sequencer Operation To check for operation of power circuit of sequencer place voltmeter lends 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 and FUA good 5 Ig limit switch 1 83 open If so check fan coil air filter or air distribution system 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 G Emergency Heat Emergency heat mode requires that room thermostat be placed in EMERGENCY HEAT position This lo out and prevents operation of heat pump outdoor unit In this mode heat is provided exclusively by electrical heaters
51. ly whenever a trace is blown on PCB it mcans cither there has been high voltage shart or high voltage has been applied to low voltage circuit This can be prevented by making sure is wired correctly before PCB has power applied to it C If PCB Fuse Keeps Blowing When low voltage fuse biows 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 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 m swired 2 Check wiring of sequencers as shown in Fig 4 sure low voltage and high voltage wiring is connected to proper sequencers 3 Check va draw on transformer If va draw is more than va rating of transformer fuse will blow this is the case replace transformer with one that has a higher va rating and meets system specifications D If Fan Runs Continuously 1 PCE has no low voltage powet check blue and black fan leads These may be switched at sequencer 2 I PCB has low voltage power check fan relay to see
52. ming on Replace bore and retainer switch if malfunction occurs 5 Using small wire with a hook on end of it remove piston B Sequencer from refrigerant flow control device body CAUTION When cleaning piston orifice be careful not to scratch or enlarge opening as this will affect operation Malfunction causes heater not to come on or never shut off Replace sequencer C Transformer A 60 transformer supplies 24 v power for control circuit Replace transformer if faulty NOTE Transformer is fused Do not short circuit oi AUG 14 2008 THU 03 50 UTC TECH PUB FAX No 317 240 5662 P 022 SCHEMATIC DIAGRAM Lo S RNOTERA L o eis YEL O LS i POWER SUPPLY BH YES 92 SEQ 1 BLK ra n SEQ 3 BL mon 15 2 32 gt Bene Ka atk o 3 SEQ T forman TRA vio Fl TB 2 BL 7 0 YEL 1 TB NOTE 2 Blu TRANS 1 FRED BAV BRN I 5 SEQ 1 SEQ el vig 6 BAN BRN THANS FR lola ORN qme BRN COMPONENT ARRANGEMENT RED SETE SEENOTE AS ve 5245 WIRING m EN GAN EQUIP T Aaa
53. miswired heater plug harness 4 Check limit switch or sequencer failure These switches should have failed in open position If output voltage is zero replace switch D Heater 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 E Trips 1 Check for low airflow due to dirty filters blocked registers or undersized duct 2 Cheek blower motor and wheel for proper operation Excessive current draw of motor will cause internal over load to trip 3 The fan speed may be low COIL DESCRIPTION AND TROUBLESHOOTING The is similar to the discontinued FE4A 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 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 that the FK4B motor reacts to changes in system static pressures to maintain constant airflow Unlike conventional fan coils where static pressure affects airflow the is a constant airflow unit The blower delivers requested airflow up to about 0 7 in of static pressure The 2 is
54. nt directly to ICM2 G Heat Pump Heating With Auxiliary Electric Heat Thermostat closes circuits R to Y Y2 and or Y1 with R to W2 Wa or E and R to 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 3s 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 AUG 14 2008 THU 03 47 UTC TECH PUB DO NOT REMOVE f OPTIONAL SAFETY GROUND daso ah DRAIN HOLE FAX No 317 240 5662 008 OPTIONAL SAFETY GROUND 196 32 4 58 78 CONTROL CONNECTOR 94079 Fig 5 FKAB ICM2 Motor Select Configuration Taps The Select taps are used by installer to configure system The ICM2 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 a amp the need for de humidification L ICM2 Control Power The 2 control power is supplied from R circuit through printed circuit runs to mot
55. nt to recognize safety information This is the safety alert symbol A 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 TION These words are used with the safety alert symbol DAN GER identifies the most serious hazards which will result in severe AUG 14 2008 THU 03 45 UTC TECH PUB FAX No 317 240 5662 002 sd E x i E E Hi 8 gt 5 lt i M eem as Minar Series A Original MERCI UO T QE v gelooi T E fux i 8 1 8 deb E E 2 _ gt i gu web en i r rst ME 8 GER be ed s 8 5 3 io song D lw S NE Ob ebat cim Last ETS BEBE ip 2220 j vient usn des A mu aln Eri i Yn des z Ae 1 uo N Y Wea TRO 3 8 8 ances 8 5 5 HEY CHADE 5 ov j B tn 1 S 1 g 2590 m RE ET m os 5 S esi E n 2 ogi oc tp 155 525 5 Ea i amp OD BRUT 2 nsns Re xn gt 525589252028 i 5 EE SeSo55F 5002 5 1
56. ntrol de vice 9 Pressurize tubing and coil then ledk check 10 Evacuate tubing and coil as necessary LIQUID TUBE STRAINER The refrigerant flow control device ds protected on indoor by a wire mesh strainer If strainer becomes plugged 1 Complete items 1 and 2 under Cleaning or Replacing Refrigerant Flow Contro Device section 2 Loosen flare fitting joint connecting refrigerant flow contro device to coil liquid refrigerant tube 3 Remove sheet metal screw holding bracket clip place Screw is located between coil and refrigerant flow control device 4 Pull bracket clip out 5 Remove refrigerant flow contro device assembly 6 Pull strainer out of coil liquid refrigerant tube and replace with new strainer V CARE AND MAINTENANCE WARNING Hinged access panel contains electrical A components and is heavy Support panel when lowering to clean unit to avoid p rsonal injury 7 WARNING Disconnect electrical power to all circuits AN before servicing Failure to do so may result in personal injury from electrica shock or moving parts WARNING As with any mechanical equipment per sonal injury can result from sharp metal edges Be careful when removing paris The minimum maintenance requirements for this equipment are as follows FAX No 317 240 5682 023 1 Inspect and clean or replace ficld supplied air filter each month or as required
57. oil from vertical condensate draim pan See Fig 14 11 Horizontal Applications Only Remove coil top seal attached with 4 screws and J shaped tube from original coil and instal it in same position on new coil See Fig 14 12 Place coil assembly in plastic condensate pan and secure using 4 screws through delta plate See Fig 14 13 Horizontal and Upflow Applications Only Attach 4 coil brackets to coil pan assembly See Fig 14 14 Horizontal Applications Place horizontal conden sate pan into position on coil pan assembly NOTE Installation of hotizantal condensate pan is not necessary for upflow or downflow applications 15 Slide complete assembly into unit 16 Reinstall fitting panel and reconnect clip securing fitting pane to condensate drain pan 17 Horizontal Applications Only Reinstall horizontal pan clip Secure with 1 screw Sec Fig 14 18 Reinstall coil access panel 19 Reconnect liquid and vapor refrigerant tubes and conden gute 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 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 SLOPE COIL UNITS COIL SUPPORT COLUMN TOP SEAL PARTIALLY H
58. on middie top element PCB PRINTED CIRCUIT BOARD B 18 24 and SOKW heaters use double pole swilnhes HPTB HEAT PUMP TERM BRD F LOW VOLTAGE FUSE 10 Largest heaters are shown smaller heaters will hava fewer elements and LVTB LOW VOLT TEAM BAD aomponenta SEQ SEQUENCEA 11 1 phase heaters ara shown wired for single suppl dircult Multiple supply ctreults may be wired directly to fusejC HVTB HIGH VOLTAGE TERMINAL BOX HUM HUMIDIFIER Fig 8 Wiring Diagram 12 94078 AUG 14 2008 THU 03 48 PM UTC TECH PUB TABLE 6 CONTROL TEST VALUES FAX No 317 240 5682 P 013 VOLTAGES 7 PIN PLUG OPERATING MODE SOR TEMAS W G R Y Pind Pin 2 Pin 3 Pin 4 Pins Pin 6 Pin 7 Electric Heating R w2 Ws3 E 24 0 0 0 24 vac 1 Spaed Coding R VY2 G 0 24vac 0 0 24vac 24 vac 2 Speed Law Speed Cooling A v1 a 0 24 vac 9 Bs 24 vac 2 Speed A G High Speed Cooling R Y Y2 a 0 24 vac 0 0 24 24 vac 1 Speed HP Cooing R Y Y2 a 0 24 vac 0 0 24 vac 1 Speed HP Heating Y Y8 G 0 24 vac D D 24 2 Speed Low Speed Cooling Y1 Gq o 24 vac 0 0 24 vac 2 Speed HP Low Speed Heating Yi a D 24 0 0 24 vac 2 Spaed HP High Speed Cooling R Y Y2 Yt G 0 24 0 0 24 2 Speed HP Hi
59. ondary 3 The fan relay 18 controlled by thermostat and fan on and off 4 Aplug is used as the connection for power and electric heaters Note the pin numbers on plug 5 A time delay relay circuit keeps fan motor running for 90 after G 16 de energized UNIT FUNCTIONS A 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 teuninal 2 Proper Wiring of Transformer Secondary 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 B Indoor Fan 1 Wiring Indoor fan motor yellow lead is wired to C termina 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 ta prevent direct short to cabinet surface AUG 14 2008 THU 03 45 PM UTC TECH PUB AP v 9 i C045 7r CO 5 z oe P Cn 0 HON tA 71 2 FAN RELAY Fig 3 Fan Col
60. or control connector pin 6 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 4 and 5 then through motor control harness to motor Jd Low Voltage Circuit Fusing and Reference The low voltage circuit is fused by a board mounted 5 amp antomotive 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 zun at SEC1 connected to metal standoff marked GROUND SCREW REQUIRED NOTE A ground screw must be in place or erratic motor operation can result K 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 T1 and T3 Transformer connection T2 is dummy terminal used for unused primary power lead The transformer secondary connec tions ate made at SEC1 and SEC2 connectors IV 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 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 humidific
61. 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 i 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 EMP This information is entered into an expression which calculates torque from speed and aitflow 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 INTEGRATED CONTROLS AND MOTOR 2 The 2 is similar to the ICM1 used in series units but cannot be used ag replacement without some modification to 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 5 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 pe
62. qi hicets E heat to turn off with fan providing ttierm stat i riot calling the fan s oc edt If independent staging is desired cor mostat Installation Instructions TROUBLESHOOTING PCB Use wiring schematic shown in Fig 4 as a guide i in troubleshooting PCB unless otherwise noted A If Fan Will Not Turn On from IF THERE 1 NO HIGH VOLTAGE TO PCB 1 Check plug receptacle connection This supplies power from heaters to 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 Jeads L1 and L2 H these are not receiving power system cannat 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 ted and C brown Be sure transformer output is between 18 and 30 vac If transformer output is incorrect and trans former s receiving correct input voltage 208v or 230v then transformer needs to be replaced with recommended transformer If no problem exists with transformer segond ary proceed to items 3 and 4 AUG 14 2008 THU 03 46 UTC TECH PUB FAX No 317 240 5662 P 005
63. quencer number 1 3 Check power leads L1 and L2 If these are not receiving power system cannot function IF HAS HIGH VOLTAGE APPLIED TO IT 1 Check low voltage transformer Jeads red and brown Be sure they are wired 10 correct locations See Fig 6 and 8 AUG 14 2008 THU 03 47 UTC TECH PUB FAX No 317 240 5662 P 010 1 RED 1 1 1 i 5 E AUX HEAT 004 aca 1 1 1 1 SH HP EFF aw TS aco I LOW MED HI GATA acta I 1 LT oe 2 2 02080 am Geist T 771 T oci 11 St 4077 Fig 7 Easy Select Board Circultry 2 Check output voltage of transformer secondary side SEC2 Check wiring of heaters a heater is miswired fuse and 1 Be sure transformer output is around 24 vac If may blow If a heater is miswired correct miswiring 7 transformer output is zeto Vac dnd transformer is receiving E correct input voltage 208v or 240v then transformer 1 pore T3 pi SIN needs to be replaced with recommended transformer If a ali s d ey un no ered pr T dd Ps transformer output 18 24 vac proceed to items 3 and 4 ermina doare cannot SUPP SIR
64. r bringi g on supplemental electric heat When thermostat is satisfied its contacts open de energizing contactor and sequencer All heaters and motors should stop CARE AND MAINTENANCE The minimum maintenance requirements for this equipment are as follows 1 Inspect and clean or replace air filter cach month or as required 2 Inspect cooling coil drain pan and condensate drain cach cooling season for cleanliness Clean as necessary 3 Inspect blower motor and wheel for cleanliness cach heating and cooling season Clean as necessary 4 Inspect electrical connections for tightness and controls for proper operation each heating and cooling season Service 85 necessary WARNING As with any mechanical equipment per sonal injury can result from sharp metal edges Be careful when removing parts A Air Filter To clean or replace air filter grasp it at bottom and lift it out of 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 B Cooling Coil Drain Pan and Condensate Drain The cooling is casily cleaned when it is dry Inspect coil and clean if
65. r used in the Fan Coil is controlled by Jow voltage signals This signal is teplaced by a 24 vde signal which is provided at circuit board terminals AUX1 and AUX2 See Fig 6 This signal is present when either G or W is present and is active in al heating and cooling modes Because 24 vde relays may not be readily available to installer a kit exists KFAIRO101ACR containing 24 vde relay which mounts directly inside cabinet User supplied 110 vac is switehed by relay to power air cleaner when G or W are present See Fig 10 and 11 In heat pump applications the G signal is present in both cooling and heating modes permitting EAC to be controlled from G signal only Por this application a user supplied 24 vac relay can be driven by G terminal eliminating need for relay kit B FK4B 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 can be wired to provide this requirement by adjusting its airflow in response to standard humidistat input Fig 12 illustrates the wiring connections to activate de humidify mode Carefully consult product airflow data for cooling and dehumidi Tying mode THERMOSTATIC EXPANSION VALVES The and 4 Fan Coils are factory equipped with hard shutoff HSO 14 FAX No 317 240 56
66. rmanently 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 contro plug to run motor FAX No 317 240 5662 7 P 007 PCB LAYOUT AND DESCRIPTION NOTE Layout of actua PCB is depicted in Fig 6 and 7 The control is a single PCB which interfaces a variable speed 2 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 primary and secondary of transformer are connected to control board The 24 vac secondary circuit includes a socket soldered into circuit at SEC2 to receive a 5 amp automotive type fuse Connection to heater pane is made through 12 eirewit connector P1 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 32v 200 percent current opening time of 5 556 maximum A Electrical Connections Eighteen 0 187 in quick connect terminals are used to provide programming selections for operating modes of 2 The 5 selection modes are listed below For additional information refer to Easy Select Configuration Taps section AUX Heat Range Violct Wire AC HP Size Blu
67. rols 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 fadction switch set for continuous operation Confirm fan operation Voltage to operate fan can be confirmed by placing voltmeter leads across terminals Fi and HI on control The reading should be 208 230v If 208 230v is not observed check the following E Is 208 230v available at pins 7 and 9 of 9 pin connector Is connection to board tight Are line voltage fuses FU1 and FU2 good 208 230v is available across terminals Fi and and fan does not operate check the following Is fan motor capacitor good Is blower wheel jammed or loose Are there any other mechanical problems preventing fan operation C Cooling On call for cooling room thermostat provides input signals to control board at terminals Y and 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 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 contro signals 5 flashes indica
68. rs toward center of unit and remove filter access panel outward Push filter up and back into unit Then slide filter out Clean filter by ising 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 COOLING COIL DRAIN PAN AND CONDENSATE DRAIN The cooling coil is casily cleaned when it is dry Inspect the coil and clean if necessary before each cooling season To check or clean cooling coil r thove coil access If 00 is coated with dirt or lint vacuum it with 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 3 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 lf 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 CAUTION Do not use caustic houschold drain cleaners in the condensate pan or near the coil Drain cleaners can quickly destroy a
69. ry Rand C 24 vac Power from transformer secondary Gand 24 vac Gall for continuous fan signal from room thermostat Yand 24 Call for heat coo signal from room thermostat O and 24 van 0 n reversing valve from room thermostat cooling Also present W2T and C 24 vac for electric heat from roam thermostat 9 Web and C 124 Defrost initiation signal trom heat pump OUTPUT VOLTAGES LOCATION NORMAL READING ncn s PURPOSE and F1 208 230 vac Power to blower motor high speed _ LO and Fi 208 230 vac Power to blower motor low speed and 24 vac Power to energize in heat pump heat and cool modes 9 pin connector 24 vile Power to energlza SEQ 1 1 4 NOTE Sequencers use DC voltage m 24 vde Power to anargize SEQ 2 im Edid 24 vdc Power to energize SEQ 3 vac volts vde volis DC Thirty see after is energized control energizes fan motor It may 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 actoss low voltage termina
70. s a trace blown it means cither there has been a high voltage short or high voltage has been applied to low voltage circuit This be prevented by making sure is wired correctly before PCB has power applied to it AUG 14 2008 THU 03 47 PM UTC TECH PUB FAX No 317 240 5682 012 THIS COMPARTMENT MUST CLOSED EXCEPT SERVICING BLOWER MOTOR ROTATION CAUTION SUITABLE FOR USE ON SYSTEMS EXCEEDING 150V GROUND ATTENTION NE CONVIENT PAS AUX INSTALLATIONS DE PLUS DE 150 V LA TERRE SCHEMATIC DIBCONNECT POWER WIRING see PLATE FORVOLTR amp HERTZ ONS 8EE NOTE 1 2 YEL APOE Yi o Pe tq BUE gena bs HAAS HTAA SGHEMATIC DIAGRAM YEL FIELO POWER WIRING J be DISCONNECT PER NEG 1 d BEE RATING PLATE a FOR VOLTS amp HERTA SEE NOTH 1 id mus a 7 GOGUNG CONTROL WIRING GONTROL ONLY TR YEL pt AUX HEAT RANGE te 282 HA Ee 4 0 o Qro SIZE 10600 YEL ve Ut HER ito 2
71. s have failed and motor must be replaced D if Motor Does Not Stop Running 1 Check for good ground between motor ground lead and transformer common lead 2 If motor continues to min remove all thermostat wires If motor stops replace circuit board 3 If motor continues to run remove the 7 pin plug If motor continues to run replace motor Vi CONDENSED VERSION OF TROUBLESHOOTING FK4B 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 a If motor is hard to turn manually replace motor If motor does not run check the components listed below according to their instructions Tf motor runs in some operation modes end not in others check for a good ground connection between motor ground and circuit board screw marked ground screw and check the room thermostat and wiring hamess 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 3t is either the circuit board or thermo stat 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 M1 and 2 If no voltage is present check power to board 230 v power enters the board through the black and yellow lead
72. setscrew 5 Position motor and blower wheel assembly to blower housing as originally oriented 6 Secure motor mount to blower housing using bolts previ ously removed 7 Attach green wire to blower housing with screw 8 Connect electrical and capacitor leads to 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 AUG 14 2008 THU 03 50 UTC TECH PUB FAX No 317 240 5662 P 021 24 eem 7 e 1 BLOWER 1 i WHEEL INLET RING iue 2 MOTOR AB amp 006 Fig 17 FF1A FF1B Motor Inlet Ring and Blower Wheel Assembly FD3A SERVICE AND TROUBLESHOOTING D Fan Relay Malfunction causes unit fan not to tun or tun continuously when thermostat calls for the fan in cooling heat pump or 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 Electrica shock can cause personal injury or death Replace relay E Heater Removal Disconnect wiring remove 2 sheet metal screws and pull heater out through open hinged access panel When replacing heater ensure Orientstion of heater clement is same as when removed 1 FAN MOTOR The motor is 2
73. ssembly 3 Remove 3 bolts holding motor mount to blower housing while supporting motor shel with hand Pull motor inlet ting and blower wheel assembly out of blower housing 5 With blower wheel inlet ting and motor mount still attached to motor 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 A 7 Clean blower motor and wheel using vacuum with a soft brush attachment Remove grease with a mild solvent such 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 ting On top of motor mount grommets Center inlet ning 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 shatt to position marked during disassembly NOTE 1f 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 17 4 Hold blower whee in place and carefully tighten
74. th 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 15 9 Rotate columns 90 pull away from coil and remove columns from assembly 40 Remove remaining 2 screws Securing to condensate pan i 11 Remove coil from condensate pan 12 Remove coil top seal Sce Fig 15 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 coi access and fitting panels 16 Reconnect liquid and vapor refrigerant tubes and conden 77 gate drain tube Install filter drier s if necessary 17 Evacuate tube set and indoor coil back seat open liquid and vapor service valves 18 Tum on electrical supplies to indoor and outdoor units 19 Check system refrigerant cherge and operation See Split System Residential AirGonditioners 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
75. ting cooling operation The call for cooling signals can be confirmed by placing voltmeter leads across low voltage terminals Y Yy and C The reading should be 24v If 24v is not available check the following s 24v available across R and C Scc Ready To Start section Tor items to check if 24v is not available Js 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 D Heating Compressor Only On a call for heat room thermostat provides an input signal to control board at terminal Y This signal causes the microprocessor to provide 24 v output signal at terminal Y to energize contactor in heat pump There is a 3 to 5 delay in output of Y signal AUG 14 2008 THU 03 51 UTC TECH PUB FAX No 317 240 5682 P 027 TABLE 9 TROUBLESHOOTING VOLTAGE READINGS AND TEST POINTS INPUT VOLTAGES NORMAL READING PURPOSE L1 and L2 208 230 vac Main power supply Input to fain coil L3 and L4 208 230 vac Powar to electric heaters spn usd 208 230 vac Power to smart control Ti and T3 208 230 vac Power to transformer SEC1 and SEC2 24 vac Power from transformer seconda
76. tional modes See Fig 6 C System Type The type of system must be selected UTC TECH PUB FAX No 317 240 5682 LOW VOLTAGE TERMINAL BLOCK P 003 R AGIHP SIZE Tel AP 8 BOARD AL NP CONFDRT HPE H 0 eS c Ge N AGHP GEM eo Y1 TIME DELAY SEO Goes ce Ej WEE JUMPER MOLEX 7 PIN z 3RD BTAGE CONNECTOR 1 i MOTOR is 0000000 W2 W3 JUMPER GROUND 2ND STAGE SCREW DE CES a MALE amp IN MALE n FASTON AUSTR 545 21 PLCS 555 CES0 30007 00 o AMP 12 PIN MATE N LOCK CONNECTOR 1 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 CEM ton heating and 375 CFM ton cooling The factory setting is See Fig D 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 heat pump heating modes 10 percent and 10 percent respec ti
77. tor for any deformation that may cause a bad connection Be sure all plugs are placed fully seated 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 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 cach 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 H all values of any 1 of operating modes checke OK and motor fails to run then motor is defective and should be replaced B Ir 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 18 C Motor Shaft Does Not Rotate Smoothly When manually turning sheft of ICM the shaft does not rotate smoothly The shaft has steps during rotation and 15 referred to as motor cogging The cogging is caused by permanent magnets passing cach pole of motor However shaft should not require excessive force to turn If shaft is VERY difficult to turn motor contra or bearing
78. 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 evapo tator pressure at outlet of coil plus spring pressure 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 refrigerant The increased refrigerant flow causes increased leaving 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 acgligible change in superheat The bi flow is used on split system heat pumps In cooling mode operates the same as a standard 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 external tubing These addi tions allow refrigerant to bypass TXV when refrigerant flow is reversed with only a 1 to 2 psig pressur drop through device When heat pump switches to defrost mode refrigerant flows through a completely open not throttled 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 F
79. vas TABLE 5 CONNECTIONS AND CONNECTOR mimon 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 1i1 TYPE CONNECTION CONNECTOR PENO DESCRIPTION Pin 1 Common to E screw terminal 2 Common to W2 screw terminal Pin 3 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 Haater Pin 6 Common to W3 screw terminal Connection Pin 7 Common to 2 and T3 quick connects 230 vac input quick connacts No connection Pin te M1 and T1 guick connacts 230 vac input Pin 10 No connection Pin 11 cannection Pin 12 No connection Pin 1 Diode OR output of E or W3 or We thermostat signals Ping Thermostat G signal Pin 3 Common to C and chassis ground ICM Motor 7 Pin Header Pin 4 Common to C and chassis ground Pin 5 to and SEC2 via 5 amp fusa Pin 8 Thermostat Y Y2 signal Pin 7 Thermostat Y1 signal IF TRACES ARE OVERHEATED ON BACK OF PCB Usually whenever there i
80. vely 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 E AC HP Time Delay Select desired time delay profile Four motor operation delay profiles provided to custamize and enhance system operation Fig 6 The selection options AB4076 Easy Select Board 1 standard 90 scc off delay factory setting 2 No delay option used for servicing unit or when a thermo stat 18 utilized to perform delay functions 3 A 30 sec 00 90 sec off delay profile used when it is desirable to allow system coils time to heat up coo down prior to airflaw 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 V TROUBLESHOOTING PCB Use Fig 7 and 8 and Tables 3 4 and 5 as guides in troubleshoot ing PCB unless otherwise noted A If Fan Wilt Not Turn On From Thermostat IF THERE I8 NO HIGH VOLTAGE TO 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 witing 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 se
81. where heat pump cannot maintain dwelling temperature without 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 C Defrost The Smart Heat PCB stages the correct amount of supplemental heat during defrost If tag much heat 15 added system stays in defrost for completion of defrost cycle even though thermostat is satisfied On next cycie 1 less element is energized during next defrost period NOTE 1t 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 Clrcult Board Diagnostic LED The 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 Sec Table 8 for LED flash codes TABLE 8 LED CODES FOR SMART HEAT PCB FLASH CONDITION INPUT SIGNALS SYSTEM OPERATION No Power Board Failure Board Failura No Lighi Flash Steady Light Stand By Condition Steady Flash or Fan Only Haat Pump Only 1 Flash only Operating Heat Pump Plus 1 Sequencer Heat Pump Plus 2 Sequencers Heat Pump Plus 3 Sequencers Flashes Y and or W2T 3 Flashes Y and or W2T Y and or W2T 4 Fl

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