Why is the ATV680 showing incorrect input (mains) voltage readings on the HMI?

Incorrect voltage readings on an ATV680 are typically caused by blown fuses, loose wiring, or a faulty RFI filter or power board.

Troubleshooting Steps

If the measured line voltage (phase-to-phase and phase-to-ground) appears correct externally, follow these checks after removing power:

1. Check main power fuses

   • Inspect the fuse indicators. A popped tab usually confirms a blown fuse.

2. Inspect RFI filter input fuses (L1, L2, L3)

   • Located on the RFI filter board (bottom-right of the enclosure when facing the drive).

3. Verify wiring connections

   • Ensure L1, L2, and L3 wires are securely connected to the RFI filter board terminals.

4. Evaluate hardware condition

   • If the issue persists, the RFI filter board or power board may need inspection or replacement by qualified field service personnel.

Example of Incorrect Readings (HMI)

While the drive is running or in idle mode:

• Mains voltage: ~338 VAC
• Phase voltages:
  • L1 = 239 VAC (incorrect, expected ~480 VAC)
  • L2 = 239 VAC (incorrect, expected ~480 VAC)
  • L3 = 480 VAC (correct)
• DC bus voltage:
  • ~680 VDC (running)
  • <20 VDC (idle)

💡 Recommendation

• Always verify wiring and fuse integrity first.
• Use the HMI readings to identify phase imbalance.
• Contact field service if internal components are suspected to be faulty.