In this month’s troubleshooting problem, you’re responding to a complaint that the temperature in a house is too warm. When you call ahead to let the customer know you’re on the way, they provide the additional information that “something is running,” but the temperature just continues to rise.
Upon your arrival, you perform a quick check to confirm the thermostat is properly set, that the temperature in the building is far beyond the set point, and that the indoor air flow is normal. Investigating further, you also find that the outdoor fan motor is operating normally, but the compressor is attempting to start and kicking off on overload. Using the diagram in Figure One and the legend shown in Figure Two, you begin your evaluation of the electrical system components.
(Note: What you also find relative to the compressor wiring is that while the diagram doesn’t show it, a start kit consisting of a potential relay and start capacitor was added to this unit on a previous service call).
Your electrical checks of the capacitors and start relay show the following results:
…4G2: 35 MFD
…Potential Relay Terminals 2 and 5: 2,500 Ohms
…Potential Relay Terminals 1 and 2: Continuity
…Start Capacitor: 220 MFD
With the compressor cooled down, your ohmmeter checks show the following:
…C to S: 3.5 Ohms
…C to R: 2.9 Ohms
…Terminal to Ground: Infinity
Your troubleshooting question: What is the next step you need to take in repairing this equipment?
Compare your answer with ours HERE.
Publication date: 8/06/2018