Overvoltage

What does 2 mean?

The DC-link voltage has exceeded its defined limits, detected by either hardware or software. This often occurs when the deceleration time is too short, or high overvoltage spikes are present in the supply. Excessive DC bus voltage can stress and potentially damage drive components.

• Deceleration time parameter (e.g., P2-02) set too short for the inertial load, causing kinetic energy to regenerate into the DC bus.
• Excessive supply voltage peaks (e.g., >480VAC for a 400V drive) on the input terminals (L1, L2, L3) due to grid disturbances or capacitor bank switching.
• Brake resistor (if installed) is disconnected, incorrectly sized, or has failed (e.g., open circuit) preventing energy dissipation.
• Motor operating in regenerative mode due to an external force driving the load faster than the commanded speed.
• Internal DC-link capacitance degradation, reducing its ability to absorb regenerative energy.

Click steps to track your progress.

1. 1

   Measure the DC link voltage (terminals DC+ and DC-) using a multimeter during a deceleration cycle.

2. 2

   Increase the deceleration time parameter (e.g., P2-02) by 50-100% and observe if the fault reoccurs.

3. 3

   Verify the brake resistor's resistance value with an ohmmeter against its nameplate specification (e.g., 20 Ohms) at its dedicated terminals (BR+ and BR-).

4. 4

   Confirm the brake chopper activation voltage parameter (e.g., P6-01) is correctly set according to the brake resistor unit specifications.

5. 5

   Check the input supply voltage (L1-L2, L2-L3, L3-L1) for stability and compare to the drive's nominal input voltage rating.