Power Loss Fault

What does 03 mean?

This fault indicates that the DC Bus voltage has remained below 85% of its nominal value for more than 5 seconds during power-up. It points to an issue with the incoming AC supply, potentially leading to unstable operation or damage if the controller attempts to operate with insufficient power.

• Transient AC supply interruption or brownout lasting longer than 5 seconds during controller power-up.
• Blown input fuse (e.g., F1, F2, F3) in the AC supply line to the controller.
• Loose or corroded AC input wiring connections at the controller's L1, L2, L3 terminals or upstream contactor.
• Rectifier bridge failure within the controller, preventing proper DC bus charging.
• Incorrectly sized or tripped upstream circuit breaker for the controller's AC input.

Click steps to track your progress.

1. 1

   1. Measure AC line voltage at the controller's L1, L2, L3 input terminals during power-up using a multimeter (e.g., Fluke 179). Verify voltage matches nameplate rating (e.g., 400V AC +/-10%).

2. 2

   2. Inspect all input fuses (e.g., F1, F2, F3) for continuity using a multimeter; replace any open fuses with specified type and rating.

3. 3

   3. Check continuity of the AC input cabling from the main disconnect to the controller's L1, L2, L3 terminals. Tighten all terminal screws to specified torque.

4. 4

   4. Monitor the DC bus voltage (e.g., at terminals P+, N-) during power-up using a DC voltmeter. Compare to expected nominal value (e.g., 560V DC for 400V AC input).

5. 5

   5. Verify the upstream circuit breaker or contactor is closed and rated appropriately for the drive's FLA (Full Load Amps).