Allen-Bradley · PowerFlex 4M Adjustable Frequency
This fault indicates that the DC bus voltage within the drive has exceeded its maximum allowable limit. Common causes include high incoming AC line voltage, transient voltage spikes, or regenerative energy from the motor, especially during rapid deceleration. Regenerative energy occurs when the motor acts as a generator, feeding power back into the drive. Ignoring this fault can lead to premature component degradation or catastrophic failure of the drive's power section.
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Measure incoming AC line voltage at terminals L1, L2, L3 for phase-to-phase values and check for spikes.
Increase the deceleration time parameter (e.g., P1-10) to allow for a slower and more controlled motor deceleration.
Verify the braking resistor's resistance (Ohms) and power rating (Watts) match the drive's requirements and application demands.
Check connections to the dynamic braking resistor terminals (e.g., BR+/BR-) for proper continuity and secure installation.
Consider implementing an AC line reactor or RFI filter on the input to mitigate incoming voltage transients.