Mains failure

What does ALARM 36 mean?

The supply voltage to the frequency converter is lost. This warning/alarm is active only if parameter 14-10 Mains Failure is not set to [0] No Function. This causes a complete loss of power to the drive and connected motor.

• Complete loss of incoming three-phase (or single-phase) AC supply voltage to the frequency converter input terminals.
• Tripped upstream circuit breaker, blown fuse, or open motor protection switch in the main power circuit.
• Loose or corroded connections in the input power path (e.g., main contactor, input reactor, terminal blocks).
• Significant and prolonged voltage sag below the frequency converter's undervoltage trip threshold (e.g., below 340V AC for 400V drive).
• Faulty internal voltage sensing circuit in the frequency converter, incorrectly detecting a mains failure.

Click steps to track your progress.

1. 1

   1. Measure the incoming AC line voltage (L1, L2, L3) at the frequency converter input terminals (e.g., R, S, T) using a multimeter.

2. 2

   2. Inspect and reset any tripped upstream circuit breakers, blown fuses, or motor protection switches in the input power circuit.

3. 3

   3. Check the tightness of all input power wiring connections at the frequency converter and any upstream isolation devices.

4. 4

   4. Review parameter P14-10 Mains Failure setting to ensure it's configured for the desired response to power loss (e.g., [0] No Function).

5. 5

   5. Monitor the AC supply voltage with a power quality analyzer to detect intermittent power loss events or severe sags.