In this month’s troubleshooting problem, the equipment that needs servicing is a split system heat pump, manufactured under the brand name Grandaire (ICP, Lewisburg, Tennessee). The indoor unit model number is WAPT304A2, and the outdoor unit model number is WCH5304KGA100. This is a 2.5-ton unit in a residential installation.
The information you receive from the dispatcher is that the customer explained the unit is operating erratically. Specifically, when the thermostat is satisfied at the end of a cycle, the compressor shuts down, but the outdoor fan motor seems to continue operating at a slower-than-normal speed.
Additional information about this situation is that it also seems that sometimes, on a call for operation, the outdoor fan motor does not want to start, causing the compressor to shut down after starting, and attempting to run through a cycle. And, there are three factors to consider regarding the history of this equipment.
- The dual capacitor was replaced approximately a month ago due to low microfarad readings;
- The unit is located in an area affected by Hurricane Irma, which caused a power supply interruption; and
- The contactor had been replaced after the storm when the power to the area was restored.
When you arrive, you check the power supply at the disconnect box, and confirm that there is power to the outdoor unit. After confirming the erratic operation described above, you remove the equipment access panel, and check the wiring diagram shown in Figure 1. Comparing the diagram to the wiring you see, you note that L1 is connected to terminals 23 on the contactor, and L2 is connected to 21.
You troubleshooting question: What is the next step you need to take in repairing this unit?
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Publication date: 10/9/2017