Where should a technician check the voltage to an energized compressor?

Measuring the voltage at the load side of the compressor contactor is the most accurate way to assess whether the compressor is receiving the correct voltage necessary for its operation. The load side refers to the terminals that deliver power to the compressor once the contactor is energized. This ensures that all components preceding the compressor, such as the disconnect and contactor, are functioning properly and that there are no issues affecting the voltage after the contactor.

Checking at this point allows the technician to determine if the compressor is adequately powered under operating conditions, which is crucial for troubleshooting issues related to heating, ventilation, and air conditioning (HVAC) systems. It can also help identify problems in the circuit that may arise from connections or the contactor's internal contacts.

Other locations such as the main electrical panel, the line side of the contactor, or the unit disconnect may not provide an accurate picture of what the compressor is experiencing, as they do not account for any potential voltage drop or other issues that might occur downstream in the circuit. Thus, verifying the voltage at the load side ensures that the technician can accurately diagnose any power-related issues affecting the compressor's performance.