Carrier 38GNA User's Manual
Contents
1. mN W HEATING amp COOLING 38GNA Air Conditioning Unit Installation and Start up Instructions NOTE Read the entire instruction manual before starting the installation SAFETY CONSIDERATIONS Improper installation adjustment alteration service maintenance or use can cause explosion fire electrical shock or other condi tions which may cause personal injury or property damage Consult a qualified installer service agency or your distributor or branch for information or assistance The qualified installer or agency must use factory authorized kits or accessories when modifying this product Refer to the individual instructions pack aged with the kits or accessories when installing Follow all safety codes Wear safety glasses and work gloves Use quenching cloth for brazing operations Have fire extinguisher available Read these instructions thoroughly and follow all warnings or cautions attached to the unit Consult local building codes and National Electrical Code NEC for special require ments It is important to recognize safety information This is the safety alert symbol A When you see this symbol on the unit and in instructions or manuals be alert to the potential for personal Injury Understand the signal word DANGER WARNING or CAU TION These words are used with the safety alert symbol DAN GER identifies the most serious hazards which will result in severe personal injury or death WARNING signifi2. Fig 1 Connect ground lead to ground lug in control box for safety Connect line power leads to contactor screw terminals L1 and L2 See Fig 5 or 6 Contactor terminals are approved for use with copper field wiring CONTROL POWER 24V Use furnace or fan coil trans former as 24v supply for system Transformer must have a minimum capacity of 30 va Bring control wiring through hole in unit service panel and connect to pigtails from unit contactor Contactor pigtails are labeled Y and C Refer to Fig 5 or 6 for system control circuit connections POWER SUPPLY Li L2 230 OR 206V 10 50Hz ES ee INDOOR CONTROLS CONT CONTACTOR IFR INDOOR FAN RELAY FACTORY CONTROL WIRING FIELD POWER WIRING CC COOLING COMPENSATOR FIELD CONTROL WIRING TC THERMOSTAT COOLING OQ COMPONENT CONNECTION _ FIELD SPLICE A92407 Fig 5 Control Circuit Connection 018 START UP Step 1 Start up Procedure 1 Back seat open liquid and suction line service valves Set thermostat selector switch at OFF Set room thermostat to desired temperature Close electrica disconnects energizing entire system Set room thermostat at COOL and fan switch as desired FAN or AUTO Operate unit for 15 minutes then check system refrigerant charge See Refrigerant Charging section nA e WwW N Motors and controls operate satisfactory in the 253 v 187 v range Do not connect charging hoses during initial start up p
3. as possible Build a frame to support the condensing unit See Fig 2 1 Insert condensing unit with frame into the wall opening 2 Extend unit approximately 1 in beyond outside finished wall and tilt to the outside to allow rainwater to drain off See Fig 3 3 Fasten unit to frame with metal straps 4 Use flashing under unit and caulk all edges to provide weathertight seal See Fig 3 WHETHER UNIT IS FLUSH OR RECESSED NOTCH IN WALL MUST EXTEND AT LEAST yo DEEPER THAN FRONT PANEL OF UNIT A65494 Fig 3 Flush or Recess Mounting Step 2 Make Piping Connections SELECT CORRECT LIQUID AND SUCTION LINE LENGTHS DIAMETERS Refer to Table 2 INSTALL REFRIGERANT LINES The condensing unit is fully charged at the factory Be sure both service valves are front seated turned clockwise to avoid loss of charge Do not remove refrigerant line connection seals from condensing unit matching coil or refrigerant tubing until ready to make actual connection at Nee point of seal Ei a nin bia cg iti ee a a fm gel id os Se Epig re t Tt oe Table 2 Tubing Data REFRIGERANT LINE LENGTH UNIT SIZE 10 to 50 ft 51 to 100 ft Diameter In Liquid 016 024 3 8 1 Maximum vertical separation for evaporator over condensing unit is 50 ft 2 Over 50 ft of vertical separation the condensing unit must be located above the evaporator For requirements beyond 50 ft obtain information from distributor or con
4. prevents restart within 5 minutes of power interruption Compressor motor is equipped with an internal protector Exces sive current or temperature causes protector to open which gives indication of an open circuit in motor winding Sufficient time should be allowed for overload to reset before assuming compres sor has an open winding Compressor motor is designed to start under low load conditions only Make sure system pressures have equalized before attempt ing to start unit Equalization takes approximately 3 minutes Owner should be informed not to short cycle unit with thermostat as this causes compressor to trip out on overload Each unit is shipped with refrigerant charge adequate for use with matching coils and refrigerant tubing kits Charge is adequate for systems using 25 ft of interconnecting tubing See unit rating plate for charge quantity See Refrigerant Charging section and Table 2 for adjustment requirements A WARNING Relieve all pressure before refrigerant system repair or final unit disposal to avoid personal injury or death Use all service ports and open all flow control devices including solenoid valves A CAUTION Do not vent refrigerant to atmosphere Recover during system repair or final unit disposal NOTE Check indoor coil piston to see if it matches the required piston shown on unit rating plate If it does not match replace indoor coil piston with piston shipped with this unit The piston s
5. to unit and observe it through a complete operating cycle If there are any performance problems in operating cycle correct them Step 3 Refrigerant Circuit Tbis circuit is difficult to check for leaks without proper equip ment Therefore if low cooling performance is suspected dealer service is required Step 4 Compressor Protection The 018 size unit is equipped with a reciprocating compressor while the 024 size has a scroll compressor In both applications the compressor motor is protected by an internal current and temperature sensitive overload Excessive current or temperature causes internal overload to open giving the indication of an open circuit in the motor windings The overload resets automatically when internal motor temperatures drop to a safe level overloads may require up to 30 minutes to reset When an internal overload is suspected of being open check by using an ohmmeter or continuity tester The scroll compressor is equipped with a low voltage dome thermostat that will interrupt low voltage power to the contactor The 024 size has time delay relay TDR as standard equipment to ensure against short cycling which can cause reverse rotation on shutdown Step 5 Compressor Removal Follow safety codes and wear safety glasses and work gloves Have quenching cloth available for Step 7 below 1 Shut off power to unit Remove rear access panel 2 Remove refrigerant from system A CAUTION D
6. allow water to get into compressor and unit control box Cabinet is equipped with drain holes at bottom of front edge Be sure holes are unclogged and free to drain SYMPTOM Compressor and condenser fan do not start Compressor does not start but con denser fan runs Compressor cycles other than nor mally satisfying thermostat Compressor operates continuously Excessive head pressure Head pressure too low Excessive suction pressure Suction pressure too low Trouble Analysis Chart CAUSE Power failure 3 Fuse blown or circuit breaker tripped Defective thermostat contactor or con trol relay Low line voltage Incorrect or faulty wiring Thermostat setting too high Faulty wiring or loose connections in compressor circuit Compressor motor burned out seized or internal overload open Defective run capacitor Refrigerant overcharged or under charged Defective compressor Low line voltage Blocked condenser Defective run capacitor Defective thermostat Faulty condenser fan motor or capacitor Restriction in refrigerant system Unit undersized for load Thermostat setting too low Low refrigerant charge Leaking valves in compressor Air in system Condenser coil dirty or restricted Dirty condenser coil Refrigerant overcharged Air in system Condenser air restricted or air short cy cling Low refrigerant charge Compressor valves leaking Restriction in liquid tube High heat load Com
7. e assembly can be removed through rear of unit NOTE Assembly must be supported when screws are removed 6 To change motor or wheel loosen wheel setscrews with wrench Remove 2 screws from blower housings Remove 2 motor clamps and free assembly from panel 7 Slide wheel and scroll from motor shaft 8 Remove wheel from blower housing by removing 2 screws at top of scroll outlet and pushing wheel through outlet 9 Reassemble in reverse procedure Be sure blower wheel is centered in housings before entire blower panel assembly is placed back in the unit 10 Connect the 2 electrical leads from the blower to the com pressor contactor 11 Replace the rear access panel and tighten the 3 screws 12 Turn on power to unit SCROLL R MOUNTING SCREWS ASSEMBLY MOUNTING SCREWS 2 TET n Ly ED T R Vee Ht Ci an IN ea PS f i en a htt pHi fh c i BLOWER I A HOUSING HOLE See A88548 Fig 7 Rear Access Panel Removed Step 2 Electrical Controls and Wiring Disconnect power to unit Check all electrical connections for tightness Tighten all screws on electrical connections If any smoky or burned connections are observed disassemble the connection s clean all parts strip wire reassemble properly use new connector if old one is burned or corroded and secure tightly Electrical controls are difficult to check without proper instru ments Therefore reconnect electrical power
8. es hazards that 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 4 WARNING Before installing or servicing system always turn off main power to system There may be more than 1 disconnect switch Turn off accessory heater power if applicable Elec trical shock can cause personal injury or death GENERAL Intake and discharge are on front of the unit A minimum service access distance of 30 in behind unit must be provided NOTE Refer to unit rating plate for ratings This condensing unit is designed for use with evaporator coils or fan coils equipped with capillary tube or piston type refrigerant control device It may also be used with evaporators which have expansion valves that equalize pressure during the off cycle or hard shut off expansion valves The 018 size with hard shut off expansion valve requires a hard start kit BEFORE INSTALLATION Check power supply voltage frequency and phase must corre spond with data on unit rating plate Power supply must be able to handle the additional load imposed by this equipment The 38GNA does not have a transformer Therefore the furnace transformer or another source must be used as a low voltage supply Transformer must have an additional capacity of 15 va above the requirement of furnace or air handler The 024 size is equipped with a time delay device which
9. hipped with outdoor unit is correct for any approved indoor coil combination Table 1 Installation Data In 38GNA 018 024 Through the Wall Clearance Dim 26 1 2 x 29 Air Clearance 36 Concrete Mounting Pad Dim 27x17x5 Service Clearance Unit is serviced through rear access panel Therefore unit can be installed with O in end clearance INSTALLATION Install condensing unit either through the wall outdoors on a slab or on the roof When installing allow sufficient space for airflow clearance wiring refrigerant piping and servicing Consult local building codes and National Electrical Code NEC for special installation requirements See Fig 1 2 and 3 and Table 1 for detailed installation data Manufacturer reserves the right to discontinue or change at any time specifications or designs without notice and without incurring obligations Catalog No 563 712 Book 1 4 PC 101 Tab Saj2a Printed in U S A Form 38GNA 2S I Pg 1 11 92 Replaces 38GNA 1SI AIR OUT AIR IN Ee 1 265 3 _ ACCESS LIQUID CONN es PANEL GUD TUBE i SUCTION T H an UBE 7 8DIA Low VOLTAGE HOLE FOR INLET SERVICE GAUGES 13 7 8 DIA HOLE amp 1 3 32 DIA K O POWER INLET A75135 Fig 1 Dimensions and Connections i YW ft ft W A88545 Fig 2 Roughing In Supporting Frame Step 1 Make Opening in Wall Make an opening approximately 26 1 2 x 29 in in a wall as close to the cooling unit
10. inue or change at any time specifications or designs without notice and without incurring obligations ee x PC 101 Catalog No 563 712 Printed in U S A Form 38GNA 2S Pg 8 11 92 Replaces 38GNA 1SI a a 2a
11. ment or personal injury maintenance should be performed by a trained technician Consumer service is recommended only for filter cleaning re placement Minimum maintenance to be performed 1 Check condenser coil for cleanliness each month during cooling season Clean as necessary but at least once at beginning of each season _ 2 Check blower motor and wheel for cleanliness and proper lubrication each cooling season Clean as needed 3 Check electrical connections for tightness and controls for proper operation each cooling season Service as necessary A WARNING As with any mechanical equipment personal injury can result from sharp metal edges etc therefore be careful when removing parts NOTE Never operate unit more than 2 minutes with rear door removed as unit damage may result ii aa e For continued high performance and to minimize possible equip ment failure periodic maintenance is essential Consult dealer for proper maintenance frequency and availability of a maintenance contract Air for unit is drawn into front of unit at the bottom and discharged out same side at the top Keep air inlet and outlet louvers unplugged and clear of any obstructions at all times Never cover unit or lean anything against it which might restrict airflow or cause hot air from upper louvers to recirculate into lower louvers Keep trash and debris away from unit Never stand on unit or use it as a support f
12. o not vent refrigerant to atmosphere Recover during system repair or final unit disposal 3 Disconnect compressor wiring at compressor terminal box 4 Using a tubing cutter cut suction and discharge hot gas lines at convenient place near compressor for easy reassembly to new compressor 5 Remove compressor hold down bolts and lift compressor out 6 Remove mounting grommets from old compressor and install on new compressor 7 Carefully unbraze suction and discharge line piping stubs from old compressor If oil vapor in piping stubs ignites use quenching cloth Braze piping stubs onto new compressor 8 Install new compressor in unit Braze suction and discharge lines to compressor piping stubs at points where cut Step 4 using field supplied copper slip couplings Ensure that com pressor hold down bolts are in place Connect wiring 9 Clean system Add new liquid line filter drier 10 Evacuate and recharge unit Step 6 Cleaning Condenser Coil Disconnect electrical power before removing access panel Re move rear access panel Since air is drawn into front of unit at bottom and discharged out the same side at the top dirt collects on front of coil and unit To clean coil flush out from inside of unit with a high velocity stream of water Be careful not to damage fins If coil is coated with oil or grease clean it with a mild detergent or an approved coil cleaning agent then rinse with clear water Do not
13. old 2 Evacuate system following appropriate steps for type of evacuation equipment used 3 3 Pressurize system with refrigerant to 10 psig and open tum counter clockwise both service valves 4 Remove gage manifold Replace valve stem and service port caps on both service valves Step 4 Make Electrical Connection Field wiring must comply with local and national fire safety and electrical codes Voltage to unit must be within range of 253v to 187v Refer to nameplate for other electrical data Contact local power company for correction of improper line voltage A WARNING According to NEC ANSI NFPA 70 and local codes the cabinet must have an uninterrupted or unbroken ground to minimize personal injury if an electrical fault should occur The ground may consist of electrical wire or metal conduit when installed in accordance with existing electrical codes Failure to follow this warning could result in an electric shock fire or death See unit s rating plate for recommended fuse size When making electrical connections provide clearance at unit for refrigerant piping connections BRANCH CIRCUIT DISCONNECT Install a branch circuit disconnect per NEC of adequate size to handle unit starting current Locate disconnect within sight from and readily accessible from unit per Section 440 14 of the NEC LINE POWER LEADS Extend leads from disconnect per NEC into unit through hole provided in service panel See
14. or ladders etc Refrigerant tubing is easily crushed or crimped therefore do not hang or stand anything on it Do not move unit after it has been installed as this may crimp tubing and cause unit to malfunction The ability to properly perform maintenance on this equipment requires certain mechanical skills and tools If you do not possess these contact dealer for maintenance A WARNING System contains oil and refrigerant under pressure Do not use a torch when disconnecting refrigerant components Wear safety goggles To disconnect refrigerant components 1 Turn off electrical power to unit 2 Recover refrigerant from unit 3 Cut component connecting tubing with tubing cutter and remove component from unit 4 Carefully unsweat tubing stubs from component Oil may ignite when exposed to torch flame Step 1 Blower Wheel and Motor Removal The blower assembly may easily be removed through the rear access panel in the following manner 1 Shut off all power to the unit 2 Loosen and remove 3 screws holding the rear access panel in place and remove rear access panel from unit See Fig 7 3 Disconnect the 2 electrical leads from the blower motor to the compressor contactor 4 Remove screws at top right and top left of blower retaining panel 5 Remove entire blower assembly by lowering rear of assembly and lifting it toward you so as to disengage it from slots in angles attached to sides of casing Entir
15. ound suction line is sealed in same manner except that suction line insulation must be cut and pushed back before grommet can be slipped into place See Fig 4 FIELD TUBING CONNECTIONS All models are equipped with 3 8 in liquid and 5 8 in suction back seated service valves with mechanical flare field connections Factory supplied 3 8 in to 3 8 in and 5 8 in to 5 8 in flare to sweat adaptor tubes are provided Field supplied couplings are required for tubing pack ages exceeding 50 ft long line applications SEAL OPENINGS LIQUID TUBE SUCTION TUBE A88546 Fig 4 Installing Grommets Step 3 Test Unit LEAK TESTING No installation is complete until all field and factory joints have been checked for leaks 1 Remove valve stem caps from both service valves and check to be sure valves are front seated turned clockwise Remove service port caps 2 Attach gage manifold to service ports of service valves and purge hoses 3 Pressurize evaporator coil and interconnecting refrigerant tubing with vapor from an external refrigerant cylinder of R 22 until the system and cylinder pressure are equalized NOTE NEVER USE A UNIT CHARGE FOR LEAK TEST ING 4 Leak test with an electronic detector a halide torch or a liquid soap solution 5 Recover refrigerant and repair any leaks 6 If system is free of leaks prepare unit for operation EVACUATION 1 Connect evacuation equipment to system gage manif
16. pressor valves leaking Refrigerant overcharged Low refrigerant charge Metering device or low side restricted Low evaporator air Temperature too low in conditioned area REMEDY Call power company Replace fuse or reset circuit breaker Replace component Determine cause and correct Check wiring diagram and rewire cor rectly Lower thermostat setting below room temperature Check wiring repair or replace Replace compressor and determine cause Determine cause and replace Remove refrigerant evacuate system and recharge Determine cause and replace Determine cause and correct Determine cause and correct Determine cause and replace Replace thermostat Replace Locate restriction and remove Decrease load or increase unit size Raise thermostat setting above room temperature Locate leak repair and recharge Replace compressor Remove refrigerant evacuate system recharge Clean coil or remove restriction Clean coil Remove excess refrigerant Remove refrigerant evacuate system and recharge Eliminate cause Locate leak repair and recharge Replace compressor Remove restriction Check for source and eliminate Replace compressor Remove excess refrigerant Locate leak repair and recharge Remove source or restriction Increase air Reset thermostat Copyright 1992 CARRIER Corp 7310 W Morris St Indianapolis IN 46231 13089 Rr ma PNP 21 ADEN a a U UL a Manufacturer reserves the right to discont
17. rocedure Loss of charge from this procedure may result in capacity reduction If necessary to add manifold gages for servicing refer to the service manual for bypass method of returning charge to system Step 2 Sequence of Operation When thermostat calls for cooling thermostat contacts close energizing contactor holding coil from 24 v external power source Contacts close energizing compressor motor and condenser fan motor with supply voltage When thermostat is satisfied contacts open de energizing contac tor holding coil and in turn breaking supply voltage circuit All motors should stop In 024 size applications the lock out relay prevents restart for up to 5 minutes Refer to presale literature Step 3 Refrigerant Charging Refer to information on unit rating plate POWER SUPPLY iLi 11L2_4 230 OR 208V CTD 19 60Hz S l bama om on INDOOR CONTROLS CTD COMPRESSOR TIME DELAY FACTORY WIRING ____ FIELD WIRED IFR INDOOR FAN RELAY ERARA DTS DOME THERMOSTAT CONT CONTACTOR _ _ SPLICE CONNECTION A88547 Fig 6 Control Circuit Connection 024 A CAUTION To prevent personal injury wear safety glasses and gloves when handling refrigerant Do not overcharge system This can cause compressor flooding SERVICE Access to all controls and unit components is through rear access panel A WARNING Because of possible damage to equip
18. sult Long Line Application Guideline 3 Charge adjustment is required when using more than 25 ft of tubing See Refrigerant Charging information on unit rating plate 4 Do not use larger than 3 4 in suction line If accessory tubing package or evaporator coil has been open for more than 5 minutes evacuate evaporator coil and tubing system Always evacuate if field supplied tubing is used See Evacuation section Ensure field supplied tubing is of refrigerant grade Insulate the suction line with insulation that has an adequate vapor barrier Evacuate tubing 1 Run refrigerant lines as directly as possible avoiding any unnecessary turns and bends 2 Tape the liquid line to the top of the insulated suction line for support 3 Suspend the refrigerant lines so they do not damage the insulation on the suction line and do not transmit vibration to the structure 4 If the refrigerant lines are too long the excess may be cut off 5 Connect tubing to the condensing unit The refrigerant tubing and evaporator coil should be leak tested upon completion When making piping connections be sure to provide clearance at unit for electrical connection Connect suction and liquid refrigerant lines to condensing unit See Fig 1 Make suction line connection first Two grommets are provided to seal the gap between refrigerant lines and unit casing Cut small grommet slip it over liquid line and push it into casing opening Gap ar
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