Applicable Systems
MicroFlex
Symptoms
The MicroFlex reports a DC bus overvoltage fault. The bus capacitor voltage exceeded the maximum safe level.
Possible Causes
- Regenerative energy from deceleration exceeding the braking capacity
- Input supply voltage at or above the upper specification limit
- Braking transistor or resistor circuit failure
Troubleshooting Steps
- Step 1: Increase the deceleration time to reduce regenerative energy
DC bus voltage stays below the threshold - Step 2: Check the braking resistor and transistor circuit
Brake circuit is functional - Step 3: Measure the input supply voltage and verify it is within range
Input voltage is within the rated range
How to Reset
To reset: Reduce the DC bus voltage below the threshold, then reset.
Source: Baldor MicroFlex Drive Manual, Baldor Electric Company/ABB
Category: PLC & VFD