Goodmans GSZ, ASZ, SSX, DSZ, GSX Sequence of Operation, MBE/AEPF with TWO Stage ASX & DSX Condensers

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SERVICING

5.0 DEFROST 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.

5.1The heat pump will be on and operating in the heating mode as described the Heating Operation in section 4.

5.2The defrost control in the heat pump unit checks to see if a defrost is needed every 30, 60 or 90 minutes of heat pump operation depending on the selectable setting by monitoring the state of the defrost thermostat attached to the outdoor coil.

5.3If the temperature of the outdoor coil is low enough to cause the defrost thermostat to be closed when the defrost board checks it, the board will initiate a defrost cycle.

5.4When a defrost cycle is initiated, the contacts of the HVDR relay on the defrost board open and turns off the outdoor fan. The contacts of the LVDR relay on the defrost board closes and supplies 24Vac to “O” and “W2”. The reversing valve is energized and the contacts on HR1 close and turns on the electric heater(s). The unit will continue to run in this mode until the defrost cycle is completed.

5.5When the temperature of the outdoor coil rises high enough to causes the defrost thermostat to open, the defrost cycle will be terminated. If at the end of the programmed 10 minute override time the defrost thermo- stat is still closed, the defrost board will automatically terminate the defrost cycle.

5.6When the defrost cycle is terminated, the contacts of the HVDR relay on the defrost board will close to start the outdoor fan and the contacts of the LVDR relay will open and turn off the reversing valve and electric heater(s). The unit will now be back in a normal heating mode with a heat pump demand for heating as described in the Heating Operation in section 4.

SEQUENCE OF OPERATION

This document covers the basic sequence of operation for a typical application with a mercury bulb thermostat. When a digital/electronic thermostat is used, the on/off staging of the outdoor unit and auxiliary heat will vary. Refer to the installation instructions and wiring diagrams provided with the MBE for specific wiring connections, dip switch settings and system configuration.

MBE/AEPF WITH TWO STAGE

ASX & DSX CONDENSERS

1.0 COOLING OPERATION

When used with the ASX & DSX two stage condens- ers, 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 “Ylow/Y1” at the condenser. The “Y2” output from the indoor thermostat must be connected to the yellow wire labeled “Y/Y2” inside the wire bundle marked “Thermostat” and the yellow wire labeled “Y/Y2” inside the wire bundle marked “Outdoor Unit” must be connected to “Y/Y2” at the condenser. The orange jumper wire from terminal “Y1” to terminal “O” on the VSTB inside the MBE/AEPF must remain con- nected.

1.1On a demand for cooling, the room thermostat energizes “G” and “Y1” and 24Vac is supplied to “G” and “Ylow/Y1” of the MBE/AEPF unit. The VSTB inside the MBE/AEPF 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 “Ylow/Y1” at the condenser and the compres- sor and condenser fan starts in low speed operation.

1.2If first stage cooling cannot satisfy the demand, the room thermostat will energize “Y2” and supply 24Vac to the MBE/AEPF unit. The blower motor will change to the cfm for high speed operation and the VSTB will supply 24Vac to “Y/Y2” at the condenser and the compressor and condenser 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 “Y/Y2” at the condenser. The blower will drop to 60% of the programmed cfm and the compressor and condenser fan will change to low speed. On most digital/electronic thermostats, “Y2” will remain en- ergized until the first stage cooling demand “Y1” is satisfied and then the “G”, “Y1” and “Y2” demands will be removed.

1.3When the first stage cooling demand, “Y1”, is satisfied, the room thermostat removes the 24Vac from “G” and “Y1”. The MBE/AEPF removes the 24Vac from “Ylow/ Y1’ at the condenser and the compressor and condenser fan are turned off. The blower motor will ramp down to a complete stop based on the time and rate programmed in the motor.

2.0Heating Operation

2.1On a demand for heat, the room thermostat energizes “W1” and 24Vac is supplied to terminal “E/W1” of the VSTB inside the MBE/AEPF unit. The VSTB will turn on the blower motor and the motor will ramp up to the speed programmed in the motor based on the settings for dip switch 1 and 2. The VSTB will supply 24Vac to heat sequencer HR1 on the electric heater assembly.

2.2HR1 contacts M1 and M2 will close within 10 to 20 seconds and turn on heater element #1. At the same time, if the heater assembly contains a second heater element, HR1 will contain a second set of contacts, M3 and M4, which will close and turn on heater element #2.

Note: If more than two heater elements are on the heater assembly, it will contain a second heat sequencer, HR2, which will control the 3rd and 4th heater elements if available.

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Contents Service Instructions Recognize Safety SYMBOLS, Words and Labels Email us at customerservice@goodmanmfg.comImportant Information Fax us at 713 Fax us at 931 438Safe Refrigerant Handling Product Identification Split System Heat Pumps R410AModel # Description Split System Air Conditioners R410A ASX130**1AA Single Piece Air Handlers AWUF****1AA MBR/MBE Air Handlers Product Identification 1824 3642 Accessories ASX13DSX/SSX16 ASX18 ASZ13 DSZ/SSZ16 ASZ18 Expansion Valve Kits FSK01A Coil Accessories Electric Heat Kitapplications Aruf Electric Heat Kitapplications Aepf Product Design Condensing UnitFigure a Capacity Control System Operation HeatingCooling Cooling CycleDefrost Cycle Heating CycleCooling Cycle System Operation AFE18-60A Control Board DescriptionTroubleshooting Chart COOLING/HP Analysis ChartServicing 61BChecking Wiring Checking THERMOSTAT, WIRING, and Anticipator3A Thermostat and Wiring Checking Voltage3B Cooling Anticipator 3C Heating AnticipatorChecking Time Delay Relay Testing Coil CircuitChecking Transformer Control Circuit Checking Cycle ProtectorTesting Compressor Contactor Single PhaseChecking Contactor AND/OR Relays Checking Contactor ContactsCopeland Comfort Alert Diagnostics Testing FAN RelayDiagnostics Table Checking Loss of Charge Protector Checking High Pressure ControlChecking LOW Pressure Control Checking CapacitorRELAY, Start 15A Resistance Check15B Capacitance Check 16A Checking FAN and Blower Motor Windings PSC Motors 16B Checking FAN and Blower Motor ECM MotorsChart on Next Chart from Previous 16D ECM CFM Adjustments MBE / Aepf 16C Checking ECM Motor WindingsCFM GE X13TM Motor Connections 16E Blower Performance Data16F Checking GE X13TM Motors Testing Compressor Windings Checking Compressor17A Resistance Test 17B Ground Test17C Unloader Test Procedure Unloader Test Procedure17D Operation Test Compressor Ground TestTesting Crankcase Heater Optional Item Testing Defrost ControlTesting Defrost Thermostat Checking Reversing Valve and Solenoid40 MBR/AR*F Electronic Blower Time Delay Relay Checking Heater Limit ControlsChecking Heater Elements Sequence of OperationMBR/AR*F with Single Stage Heat Pumps Heating OperationMBE/AEPF with Single Stage GSX, ASX and SSX Condensers 41 MBE/AEPF with GSX, SSX, ASX, DSXDefrost Operation 41A MBE/AEPF with Single Stage GSZ, SSZ, & ASZ Heat Pumps Sequence of Operation MBE/AEPF with TWO Stage ASX & DSX CondensersMBE/AEPF with TWO Stage ASZ & DSZ Heat Pump Units Electric Heater Optional Item Formulas 61A Checking Heater Limit Controls61B Checking Heater Fuse Link Optional Electric Heaters Leak Testing Nitrogen or NITROGEN-TRACED Refrigeration Repair PracticeEvacuation Brazing MaterialsCharging EvacuationFinal Charge Adjustment Checking Compressor Efficiency105B Thermostatic Expansion Valve TXV ValvesPressure vs. Temperature Chart 410A Required Liquid Line Temperature Overfeeding UnderfeedingSuperheat Checking Subcooling109A TWO Speed Application Checking Expansion Valve OperationFixed Orifice Restrictor Devices Subcooling Formula = Sat. Liquid Temp. Liquid LineChecking Restricted Liquid Line Overcharge of RefrigerantNON-CONDENSABLES Compressor BurnoutAccessories for lines greater than 80 feet Refrigerant PipingLong Line SET Application R-410A Tube SizingInstallation Requirements AIR Handler External Static Initial System ChargingStatic Pressure Drop Coil Static Pressure DropTotal External Static Accessories Wiring Diagrams ALL Fuel System AFE18-60A Control Board10kw 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
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