Goodmans GSZ, SSX, ASX, DSX MBE/AEPF with TWO Stage ASZ & DSZ Heat Pump Units, Cooling Operation

Page 57

SERVICING

For the 3rd and 4th heater elements to operate on a second stage heat demand, the PJ4 jumper on the VSTB inside the MBE/AEPF must be cut. With the PJ4 jumper cut, the VSTB will run the blower motor on low speed on a “W1” only demand. If the first stage heat demand, “W1” cannot be satisfied by the heat pump, the temperature indoors will continue to drop. The room thermostat will then energize “W2” and 24Vac will be supplied to HR2 on the heater assembly and the blower motor will change to high speed. When the “W2” demand is satisfied, the room thermostat will remove the 24Vac from “W2” and the VSTB will remove the 24Vac from HR2. The contacts on HR2 will open between 30 to 70 seconds and heater elements #3 and #4 will be turned off and the blower motor will change to low speed. On most digital/ electronic thermostats, “W2” will remain energized until the first stage demand “W1” is satisfied and then the “W1” and “W2” demands will be removed.

2.3When the “W1” heat demand is satisfied, the room thermostat will remove the 24Vac from “E/W1” and the VSTB removes the 24Vac from HR1. The contacts on HR1 will open between 30 to 70 seconds and turn off the heater element(s) and the blower motor ramps down to a complete stop.

MBE/AEPF WITH TWO STAGE ASZ & DSZ HEAT PUMP UNITS

3.0Cooling Operation

When used with the ASZ & DSZ two stage heat pumpS, dip switch #4 must be set to the OFF position on the VSTB inside the MBE/AEPF. The “Y1” output from the indoor thermostat must be connected to the purple wire labeled “Ylow/Y1” inside the wire bundle marked “Thermostat” and the purple wire labeled “Ylow/ Y1” inside the wire bundle marked “Outdoor Unit” must be connected to “Y” at the heat pump. The “Y2” output from the indoor thermostat must be connected to the yellow wire labeled “Y/Y2” inside the wire bundle marked “Ther- mostat” and the yellow wire labeled “Y/Y2” inside the wire bundle marked “Outdoor Unit” must be connected to “Y/ Y2” at the heat pump. The orange jumper wire from terminal “Y1” to terminal “O” on the VSTB inside the MBE/AEPF must be removed.

On heat pump units, when the room thermostat is set to the cooling mode, 24Vac is supplied to terminal “O” of the VSTB inside the MBE unit. The VSTB will supply 24Vac to “O” at the heat pump to energize the reversing valve. As long as the thermostat is set for cooling, the reversing valve will be in the energized position for cooling.

3.1On a demand for cooling, the room thermostat energizes “G” and “Y1” and 24Vac is supplied to “G” and “Ylow/Y1” of the MBE unit. The VSTB inside the MBE will turn on the blower motor and the motor will ramp up to 60% of the speed programmed in the motor based on the settings for dip switch 5 and 6. The VSTB will supply 24Vac to “Y” at the heat pump and the compressor and outdoor fan starts in low speed operation.

3.2If first stage cooling cannot satisfy the demand, the room thermostat will energize “Y2” and supply 24Vac to “Y/ Y2”of the MBE unit. The blower motor will change to the cfm for high speed operation and the VSTB will supply 24Vac to “Y2” at the heat pump. The compressor and outdoor fan will change to high speed operation. When the “Y2” demand is satisfied, the thermostat will remove the “Y2” demand and the VSTB will remove the 24Vac from “Y2” at the heat pump. The blower will drop to 60% of the programmed cfm and the compressor and outdoor fan will change to low speed operation. On most digital/ electronic thermostats, “Y2” will remain energized until the first stage cooling demand “Y1” is satisfied and then the “G”, “Y1” and “Y2” demands will be removed.

3.3When the first stage cooling demand, “Y1”, is satisfied, the room thermostat removes the 24Vac from “G” and “Y1”. The VSTB removes the 24Vac from “Y’ at the heat pump and the compressor and outdoor fan are turned off. The blower motor will ramp down to a complete stop based on the time and rate programmed in the motor.

4.0 Heating Operation

On heat pump units, when the room thermostat is set to the heating mode, the reversing valve is not energized. As long as the thermostat is set for heating, the reversing valve will be in the de-energized position for heating except during a defrost cycle. Some installations may use one or more outdoor thermostats to restrict the amount of electric heat that is available above a preset ambient temperature. Use of optional controls such as these can change the operation of the electric heaters during the heating mode. This sequence of operation does not cover those applications.

4.1On a demand for first stage heat with heat pump units, the room thermostat energizes “G” and “Y1” and 24Vac is supplied to “G” and “Ylo/Y1” of the MBE/AEPF. The VSTB will turn on the blower motor and the motor will ramp up to 60% of the speed programmed in the motor based on the settings of dip switch 1 and 2. The VSTB will supply 24Vac to “Y” at the heat pump. The compressor will start on high speed and outdoor fan will start on low speed on a “Y1” heating demand but the blower motor will deliver only 60% of the programmed cfm for high speed heating operation.

4.2If a thermostat that provides a “Y2” demand in heating is used and first stage heating cannot satisfy the demand, the room thermostat will energize “Y2” and supply 24Vac to “Y/Y2” of the MBE unit. The blower motor will change to the cfm for high speed heating operation and the VSTB will supply 24Vac to “Y/Y2” at the heat pump.

57

Page 56 Page 58
Image 57
Page 56 Page 58
Contents Service Instructions Email us at customerservice@goodmanmfg.com Recognize Safety SYMBOLS, Words and LabelsImportant Information Fax us at 713 Fax us at 931 438Safe Refrigerant Handling Split System Heat Pumps R410A Product IdentificationModel # Description Split System Air Conditioners R410A ASX130**1AA Single Piece Air Handlers AWUF****1AA MBR/MBE Air Handlers Product Identification 1824 3642 ASX13 AccessoriesDSX/SSX16 ASX18 ASZ13 DSZ/SSZ16 ASZ18 Expansion Valve Kits FSK01A Coil Accessories Electric Heat Kitapplications Aruf Electric Heat Kitapplications Aepf Condensing Unit Product DesignFigure a Capacity Control Heating System OperationCooling Cooling CycleHeating Cycle Defrost CycleCooling Cycle System Operation Description AFE18-60A Control BoardCOOLING/HP Analysis Chart Troubleshooting Chart61B ServicingChecking THERMOSTAT, WIRING, and Anticipator Checking Wiring3A Thermostat and Wiring Checking Voltage3C Heating Anticipator 3B Cooling AnticipatorTesting Coil Circuit Checking Time Delay RelayChecking Transformer Control Circuit Checking Cycle ProtectorSingle Phase Testing Compressor ContactorChecking Contactor AND/OR Relays Checking Contactor ContactsTesting FAN Relay Copeland Comfort Alert DiagnosticsDiagnostics Table Checking High Pressure Control Checking Loss of Charge ProtectorChecking LOW Pressure Control Checking Capacitor15A Resistance Check 15B Capacitance CheckRELAY, Start 16B Checking FAN and Blower Motor ECM Motors 16A Checking FAN and Blower Motor Windings PSC MotorsChart on Next Chart from Previous 16C Checking ECM Motor Windings 16D ECM CFM Adjustments MBE / AepfCFM 16E Blower Performance Data 16F Checking GE X13TM MotorsGE X13TM Motor Connections Checking Compressor Testing Compressor Windings17A Resistance Test 17B Ground TestUnloader Test Procedure 17C Unloader Test Procedure17D Operation Test Compressor Ground TestTesting Defrost Control Testing Crankcase Heater Optional ItemTesting Defrost Thermostat Checking Reversing Valve and SolenoidChecking Heater Limit Controls 40 MBR/AR*F Electronic Blower Time Delay RelayChecking Heater Elements Sequence of OperationHeating Operation MBR/AR*F with Single Stage Heat Pumps41 MBE/AEPF with GSX, SSX, ASX, DSX Defrost OperationMBE/AEPF with Single Stage GSX, ASX and SSX Condensers 41A MBE/AEPF with Single Stage GSZ, SSZ, & ASZ Heat Pumps MBE/AEPF with TWO Stage ASX & DSX Condensers Sequence of OperationMBE/AEPF with TWO Stage ASZ & DSZ Heat Pump Units Electric Heater Optional Item 61A Checking Heater Limit Controls 61B Checking Heater Fuse Link Optional Electric HeatersFormulas Refrigeration Repair Practice Leak Testing Nitrogen or NITROGEN-TRACEDEvacuation Brazing MaterialsEvacuation ChargingChecking Compressor Efficiency Final Charge AdjustmentTXV Valves 105B Thermostatic Expansion ValvePressure vs. Temperature Chart 410A Required Liquid Line Temperature Underfeeding OverfeedingSuperheat Checking SubcoolingChecking Expansion Valve Operation 109A TWO Speed ApplicationFixed Orifice Restrictor Devices Subcooling Formula = Sat. Liquid Temp. Liquid LineOvercharge of Refrigerant Checking Restricted Liquid LineNON-CONDENSABLES Compressor BurnoutRefrigerant Piping Accessories for lines greater than 80 feetLong Line SET Application R-410A Tube SizingInstallation Requirements Initial System Charging AIR Handler External StaticCoil Static Pressure Drop Total External StaticStatic Pressure Drop ALL Fuel System AFE18-60A Control Board Accessories Wiring Diagrams10kw and Below, One Stage Electric Heat OT/EHR18-60 #2 GRD PLM PLF XFMR-R XFMR-C After Installing Optional Heat KIT, Mark AN X Provided Above HKR Heat Kit GRD PLM PLF
Top Page Image Contents