SERVICE MANUAL FOR 6536 “-” AND “A” SERIES TWO TON PACKAGED HEAT PUMPS
TABLE OF CONTENTS 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 18A. 19. 19A. 20. 21. Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Accessibility Of Appliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Unit Dimensions And Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2. ACCESSIBILITY OF APPLIANCE The accessibility of this appliance will vary from one installation to another. It shall be left to the service technicians judgement, the best method of attaining access to perform service. 3.
. UNIT SPECIFICATIONS AND IDENTIFICATION 4
. UNIT DEPICTION FIGURES 5
. THERMOSTAT SPECIFICATIONS THERMOSTAT - 6795B3451 SUB-BASE - 7330-3401 SET TEMP. RANGE: 55 TO 90 DEGREES F. DISPLAY TEMPERATURE: -20 TO 160 DEGREES F. SCALE: DEGREES FAHRENHEIT DISPLAY FORMAT: LIQUID CRYSTAL DISPLAY RESOLUTION: ONE DEGREE F. ACCURACY: ± 2% OF DISPLAY TEMPERATURE RANGE SAMPLING RATE: EVERY 30 SECONDS POWER SOURCE: 12 VDC NON-REGULATED, NON-FILTERED ± 2 VOLTS OPERATING TEMPERATURE: -10 TO +55 DEGREE C. OUTPUT LOAD: 40 mA MINIMUM TO 1.
systems from the on-board generator and the cooling demand does not require that both systems operate, stage two will shut down leaving stage one in operation. Heat operation always energizes both stages, however, only stage one operates if power is not available to circuit #2. B. the compressors. This is to allow time for generators to stabilize when initially starting. The balance of the delay (2.5 minutes) occurs when the compressors cycle off.
In gas heat mode, the gas furnace will provide the only source of heat and the heat pump is locked out. NOTE The temperature displays in degrees Fahrenheit as a factory set default (See Figure 2). To display in degrees Celsius, move the jumper marked “F” and “C” to bridge between middle pin and position “C”, then cycle 12 volt power off and then back on. WIRING THE WALL THERMOSTAT OEM must supply these mating parts to connect these thermostats per Figure 1.
6536-335* 2-STAGE HEAT PUMP WITH BACKUP HEAT THERMOSTAT OPERATION TABLE Mode Switch Fan Mode Switch Fan Speed Switch Calling 1 Cool Auto Lo No 2 Cool Auto Lo Stage 1 1 Degree Above Set ID fan low, compressor #1 and OD blower low cycle as needed 3 Cool Auto Lo Stage 2 2 Degrees Above Set ID fan low, compressors #1 and #2 and OD blower high cycle as needed 4 Cool On Lo No 5 Cool On Lo Stage 1 1 Degree Above Set ID fan low continuous, compressor #1 and OD blower low cycle as need
8. THERMOSTAT CONTROL PANEL A. OPERATION Your air conditioner is operated from the control panel located on the electronic wall mounted thermostat. When the furnace is connected to this thermostat, it will be operated from the same control panel. 3. Identification and operational descriptions for all control panel switches and display are listed below: 1. 2. Liquid Crystal Display - We will start with the display because the display will be visible any time the system is in operation.
B. TESTING Place the thermostat system switch into the “OFF” position. Once all safety precautions have been met, reinstate power to all systems; thermostat, cooling and heating. COOLING Move the system switch to COOL. The display will indicate room temperature. Adjust the setpoint above room temperature. Move the fan switch to LOW ON. The fan operates continuously at low speed.
10. INDOOR BLOWER MOTOR REMOVAL 1. Remove indoor blower access panel. 5. Remove motor assembly from scroll. 2. Disconnect wiring from motor terminal block and capacitor. 6. Remove blower wheel and motor mounting bracket. 3. Remove 4 screws from venturi (See #1, Figure 7). 4. Remove 3 screws from motor mount bracket (See #2, Figure 7). Note: Upon reassembly, the references made on Figures 7 and 8 shall be used for proper reassembly. SIDE VIEW Section 1.
END VIEW 1. Wheel must be mounted with a minimum of 5/16" clearance to scroll sides. 2. Apply grease to motor shaft before assembling wheel. 3. Torque set screw on flat of shaft to 110 #10 in. lbs. 11. OUTDOOR BLOWER MOTOR REMOVAL 1.It will be necessary to remove the top panel of the unit. 6. Remove 4 screws from venturi (See #1, Figure 10). 1. Remove 4 screws that attach scroll housing to basepan (See #1, Figure 9). 7. Remove 4 screws from motor mount bracket (See #2, Figure 10). 2.
BOTTOM VIEW 1. Wheel must be mounted with a minimum of 1/4" clearance to both venturis. 2. Apply grease to motor shaft before assembling wheel. 3. Torque set screw on flat of shaft to 110 #10 in. lbs.
SIDE VIEWS 1. Position motor with terminal block opposite motor mount clamp. 2. Torque nut to 65 in. lbs. min. 3. Ground wire terminal assembles between screw head and washer. Wrap wire around motor mount leg to take up slack. 4. Wire tie capacitor wires to mount leg.
12. BY-FLOW RESTRICTOR REPLACEMENT 1. Remove top panel. 2. Remove Section C (See Figure 11). 3. Remove outdoor blower. Follow steps 1-4 in Outdoor Blower Motor Removal Section. 4. Be certain at this point that the refrigerant charge has been removed from the system/systems being serviced. 5. Remove clamps holding restrictor in place (See #17, Figure 12). 6. Unbraze by-flow restrictor from points 16. Make note of plumbing locations for new restrictor. Must be installed in same manner.
13. INDOOR COIL REPLACEMENT 1. Refer to Outdoor Coil Replacement (Steps 1 through 7). 2. Remove screws from bottom of step panel (See #6, Figure 12). 3. Remove freeze thermister located on indoor blower side of evaporator coil (pull top of indoor blower assembly outward if necessary). 4. Pull step panel slightly off to one side. 5. Unbraze refrigerant from points (See #1 and #5, Figure 12). Protect wiring and insulation from torch flame. 6. Remove screws (See #7, #8 & #9, Figure 12).
14. OUTDOOR COIL REPLACEMENT 1. Remove top panel. 2. Remove screws along wirebox side of coil (See #10, Figure 12). 3. Remove corner panel (See Section C, Figure 11). 4. Be certain at this point that the refrigerant charge has been removed from the systems. 5. Make note of plumbing locations. The plumbing will have to go back to the same locations on the new coil. 6. Unbraze discharge and liquid lines at points #2 and #4, Figure 12. 7. Remove freeze thermister. 8. Remove condenser coil. 15.
17. WIRING DIAGRAMS - THERMOSTAT Diagram 1976E119 Electronic Wall Thermostat Assembly (12 VDC) - 6536-3451 Thermostat plug positions on the p.c. board. If no voltage is detected at the p.c. board connector, check for voltage at the thermostat. Note: All functions of this heat pump are subject to thermostat time delays according to the operation manual.
18.
18A.
19.
19A.
20. SERVICE PROBLEMS AND POSSIBLE SOLUTIONS COOLING MODE Problems Possible Solutions 1. Nothing Runs - Cooling Mode No A/C Voltage, No 12 VDC, Thermostat, Wiring, P.C. Board 2. IDFM Runs, No Compressor, No ODFM Cooling Freeze Thermistor - (Insufficient Indoor Air Flow), Thermostat, Wiring, Compressor, Contactor, P.C. Board 3. IDFM Runs, ODFM Runs, No Compressor Insufficient Voltage To Unit, Run Capacitor, Start Device, Overload, Wiring, Compressor 4. IDFM Runs, Compressor Runs, No ODFM 5.
21. ELECTRICAL FLOW CHARTS 6536 SERIES With the use of these flow charts, you will be able to quickly identify a non-working problem. Determine if the problem is high or low voltage and then solve the problem. To use these flow charts, start at the top left corner. Using a volt-ohm meter, check what is indicated in that box. If the answer to what is indicated is No, work horizontally until you find the problem. When the answer is Yes or OK, work the chart downward until you locate the problem.
A.
COOLING MODE CHECK/NO GREEN L.E.D. LIGHT FY/Y CIRCUIT TO THE THERMOSTAT Note: The green light on the 6536A model has some new functions: 1. 2. 3. If the light is on solid, then everything is OK. If the light is blinking slowly, the unit is in a 3 minute time delay. If the light is blinking fast, there is either no line voltage to Circuit #1 or one of the thermistors are open.
I.D. BLOWER LOW SPEED THERMOSTAT ON LOW FAN COOL ONLY Note: All operating functions subject to thermostat time delays.
I.D. BLOWER HIGH SPEED THERMOSTAT ON HIGH FAN COOL ONLY Note: All operating functions subject to thermostat time delays.
COMPRESSOR #1 CHECKOUT THERMOSTAT CALLING FOR COMPRESSOR COOLING ONLY Note: All operating functions subject to thermostat time delays.
COMPRESSOR #2 CHECKOUT THERMOSTAT CALLING STAGE 2 COOLING ONLY Note: All Operating Functions Subject To Thermostat Time Delays 31
CHECKOUT OUTDOOR BLOWER LOW SPEED HEATING AND COOLING MODES 32
CHECKOUT OUTDOOR BLOWER HIGH SPEED HEATING AND COOLING MODES 33
B.
HEAT/MODE CHECKOUT/NO GREEN L.E.D.
HEAT MODE I.D. BLOWER CHECKOUT Note: High Fan Speed Is Energized Only. All Operating Functions Subject To Thermostat Time Delays.
COMPRESSOR #1 CHECKOUT HEAT MODE Note: All Operating Functions Subject To Thermostat And P.C. Board Time Delays. Sub-base Must Be In The Electric Mode.
HEAT PUMP COMPRESSOR #2 CHECKOUT (HEAT MODE) Note: All Operating Functions Subject To Thermostat And P.C. Board Time Delays. Sub-base Must Be In Electric Mode.
REVERSING VALVE CHECKOUT HEAT MODE Note: Reversing Valve Is Energized In The Heat Mode And Is Subject To Thermostat And P.C. Board Time Delays. Note: If Compressor And Fan Motors Not Running, Refer To Proper Checkouts. Once The Reversing Valve Has Energized, The P.C. Board Locks The Valve Into An Energized Position Until The Wall Thermostat Is Put In The Cool Position And Actually Has A Demand For Cooling, Sending 12 VDC Down Y1.
RV Products A Division of Airxcel, Inc. P.O.
