Input Phase Loss

What does E.ILF mean?

This fault occurs when Pr.872 (Input phase loss protection selection) is enabled ('1') and one of the three phases of the input power supply to a three-phase model inverter is lost. The inverter immediately shuts off its output to prevent damage. This condition indicates a break, loose connection, or failure in one of the incoming power lines. Continued operation with a phase loss can lead to severe damage to the inverter's input rectifier bridge.

• Blown fuse or tripped circuit breaker on one of the three input phases upstream of the inverter.
• Loose connection or broken conductor in one of the input phases (R, S, T) between the supply and inverter.
• Failure of an external contactor or relay causing loss of one phase to the inverter.
• Power utility issue leading to a single-phase loss at the facility or specific circuit.

Click steps to track your progress.

1. 1

   Measure voltage across each phase of the input power supply at terminals R, S, T to identify the missing phase (e.g., R-S, S-T, T-R should be balanced).

2. 2

   Check all input fuses and circuit breakers upstream of the inverter for continuity or tripped status.

3. 3

   Inspect and tighten all input power connections from the main disconnect through to the inverter terminals (R, S, T).

4. 4

   Verify that parameter Pr.872 (Input phase loss protection selection) is set to '1' (enabled) as per the fault description.

5. 5

   If an input contactor is used, check its contacts for signs of pitting or failure, and verify coil operation.