Undervoltage

What does 4631 mean?

An undervoltage condition has been detected or reported in the drive or terminal. This means the supply voltage to the component has dropped below its minimum operational threshold. Undervoltage can cause erratic drive behavior, unstable control, or complete power loss, potentially damaging sensitive electronics if power fluctuates significantly.

• Input AC supply voltage sag below the drive's minimum operating threshold (e.g., below 340VAC for a 400VAC drive) during heavy load transients.
• Blown fuse or tripped circuit breaker in the main power supply line to the drive's input terminals (e.g., L1, L2, L3).
• Loose or corroded connections on the input power terminals (e.g., L1, L2, L3) of the drive causing increased resistance and voltage drop.
• Undersized power cables leading to excessive voltage drop under motor load conditions.
• Malfunctioning power supply unit (PSU) providing auxiliary control voltage to the drive's control board.

Click steps to track your progress.

1. 1

   Measure the incoming AC supply voltage at the drive's input terminals (e.g., L1, L2, L3) using a multimeter and compare it to the drive's nominal input voltage (P1-01).

2. 2

   Inspect all fuses and circuit breakers protecting the drive's power circuit; reset or replace any that are open or show high resistance.

3. 3

   Power down the drive and tighten all connections at the main input power terminals (e.g., L1, L2, L3) and the upstream distribution block or contactor.

4. 4

   Verify the integrity and sizing of the input power cabling from the main disconnect to the drive for proper current carrying capacity.

5. 5

   Check the DC bus voltage (e.g., monitored via drive display R0-03 or at internal test points) to ensure it is stable and within expected limits (e.g., ~560VDC for a 400V drive).