Line Synchronization Fault

What does F10 mean?

The drive has detected a missing input line phase, as indicated by phase supervision for both diode supply (S1) and active front end (S2). This means one or more incoming power phases are not present or severely degraded. Running with a missing phase can cause damage to the drive and connected equipment.

• Complete loss of one or more incoming supply phases due to a tripped breaker, blown fuse, or utility outage.
• Loose or high-resistance connection in one of the input power phases (L1, L2, or L3) to the drive.
• Faulty input rectifier bridge (diode bridge) or Active Front End (AFE) converter in the drive.
• Incorrect wiring of the input phases, leading to an open circuit or phase reversal.
• Input contactor main poles not closing correctly or one pole failing to make contact.

Click steps to track your progress.

1. 1

   Measure the incoming line voltage phase-to-phase (L1-L2, L2-L3, L3-L1) and phase-to-ground at the drive input terminals using a true RMS voltmeter. Ensure all three phases are present and balanced.

2. 2

   Inspect all input fuses and circuit breakers for continuity and proper operation. Check for tripped breakers or blown fuses.

3. 3

   Verify tightness of all input power connections at the main breaker, contactor, and drive input terminals (L1, L2, L3). Re-torque to manufacturer specifications.

4. 4

   Check the state of the input contactor; ensure all main poles are closing simultaneously and making good contact. Inspect contactor contacts for pitting or wear.

5. 5

   If the input power is confirmed stable and connected, the fault may indicate an internal issue with the drive's rectifier section; consider replacement or factory service.