Mains phase loss

What does 4 mean?

A phase is missing on the supply side, or the mains voltage imbalance is excessively high. This message can also indicate a fault within the input rectifier on the frequency converter. Unresolved mains phase loss can lead to severe damage to the frequency converter or connected motor.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Inspect the frequency converter's input rectifier for signs of damage or overheating, as this can also trigger the alarm.