What is the coil of a potential relay connected to in a compressor system?

In a compressor system, the coil of a potential relay is connected to the common and start terminals of the compressor. This is important because the potential relay is designed to sense the voltage difference across the start winding of the motor once the compressor begins operating.

When the system powers up, the potential relay measures the potential (voltage) created by the difference in the magnetic fields of the common and start windings. As the compressor starts and reaches a certain speed, the relay activates and disconnects the start winding from the circuit, allowing the run winding to carry the load independently. This is essential for efficient operation of the compressor and prevents overheating or damage that could occur if the start winding were to remain energized longer than necessary.

Connecting the potential relay to the run and neutral terminals, the time delay switch, or the overload protection device would not facilitate this critical function of sensing and disconnecting the start winding, thereby rendering those options unsuitable for the mechanism the potential relay serves.