Phase loss and incorrect phase sequence in a three-phase heat pump

Three-phase units are equipped with protections against phase loss, voltage imbalance, and in certain cases, incorrect phase sequence.

Phase loss

This may be due to a fuse, contact, cable, or a power supply issue.

Voltage imbalance

A large difference between phases puts stress on electrical components and the inverter.

Phase sequence

In equipment that requires it, an incorrect phase sequence may prevent startup.

Check

All three phases are measured, and the correct connection is verified according to the electrical diagram.