DC link voltage high

What does WARNING 5 mean?

The DC-link voltage is higher than the warning limit, which depends on the frequency converter's voltage rating. The unit remains active but operating at an elevated DC link voltage can shorten component life or lead to an overvoltage trip.

• High incoming AC mains voltage exceeding the frequency converter's nominal input range.
• Motor operating in regenerative mode (e.g., braking a high inertia load) without sufficient braking resistor capacity.
• Excessively fast deceleration ramp-down time (P3-42, P3-44) for the connected load.
• Faulty or undersized external braking resistor (if installed), unable to dissipate regenerative energy.
• Internal fault in the frequency converter's DC-link voltage regulation circuit.

Click steps to track your progress.

1. 1

   Measure the incoming AC mains voltage (L1-L2, L2-L3, L3-L1) and confirm it is within the frequency converter's specified operating range.

2. 2

   Monitor the DC-link voltage on the frequency converter's display (parameter 16-01 DC Link Voltage) during operation, especially during deceleration.

3. 3

   Increase the deceleration ramp time (P3-42 for ramp 1, P3-44 for ramp 2) to reduce regenerative energy feedback.

4. 4

   Verify the integrity and sizing of the external braking resistor (if used) and its connections to the frequency converter's brake terminals.

5. 5

   Adjust braking functions in parameters like P2-10 (Brake Function) or P2-11 (Brake Resistor Ohms) if a braking resistor is installed.