Goodman Package Heat Pump
Re: Contactor Won't Energize
The thermostat is calling and 24VAC power is present on "Y" but the contactor will not engage.
► The Goodman GPH13 package heat pump breaks "Common" to the contactor through the High and Low Pressure Switches.
►If the pressure safeties are "closed" the contactor should energize as soon as 24VAC is present on "Y" (no time delays).
Qty |
Possible Causes: |
|
Out of Refrigerant |
|
Bad Low pressure Switch |
|
Bad High Pressure Switch |
|
Bad Contactor |
CHECKOUT:
1. Check High Voltage Power
- Remove power from the unit by pulling the service disconnect or by turning off power at the breaker.
- IMPORTANT! It is very common to have multiple power supplies to a heat pump package unit.
- Open the service access panel and inspect for any burnt wiring.
- Re-apply power to the unit.
- Check for 230VAC across L1 and L2 of the compressor contactor.
- No Power ⇒ Check Disconnect and Breakers
2. Check Low Voltage Power
- Set the thermostat to call for either heating or cooling.
- At the low voltage wiring connections of the outdoor unit, check for 24VAC between "R" (Red) and "C" (Blue).
- No Power = Bad Transformer/Blown fuse or Loose Wiring
- Check for 24VAC between "Y" Yellow and "C" Blue .
- No Power = No Call from Thermostat ⇒ Recheck Stat
- Check for 24VAC across both sides of the compressor contactor coil.
3. Check Refrigerant Charge
- Hook-up refrigerant gauges to the unit and observe pressure readings.
- Low Pressure Switch should open below 10 psig.
- High Pressure Switch should open above 450 psig.
4. Test Safety Circuit
- Important Note! Remember that the safeties break the "Common" side of 24VAC power.
- Check for 24VAC power between "Y" Yellow and the "YL/PK" Yellow/Pink wire at the transformer. *("Yellow" on 5 ton model)
- No Power = No Call from Thermostat ⇒ Recheck Stat
- If there is no connector, "Skin" a small section of the connector wire between the Low Pressure Switch and the High Pressure Switch.
- Check for 24VAC between "Y" (Yellow) and the skinned section of wire (or at the connector) between the pressure safeties.
- No Power Present = Open Low Pressure Switch
- Power Present ⇒ Recheck for 24VAC at contactor.
- No Power at Contactor + Power at Connector Wire = Open High Pressure Switch