Investigation sequence
Confirm regeneration timing
Tie the trip to deceleration, load lowering, winder action, fan coast-down or other regenerative machine behavior.
Review ramp and stop configuration
Check deceleration time, stop method, overvoltage stall/control and braking enable settings.
Inspect braking hardware
Verify resistor connection, resistance, thermal contact, chopper transistor path and any external braking unit status.
Validate bus feedback
If measured bus behavior does not match the displayed fault, consider DC-bus sensing or feedback scaling.
Check system energy
For common DC bus, regenerative front end or multi-motor equipment, identify whether another drive is returning energy into the bus.
Stop conditions
- Unknown braking resistor rating
- Repeated overvoltage despite long decel
- Common DC bus without system drawing
- Evidence of overheated braking components
Linked records
The motor is returning energy to the DC link faster than the drive can absorb, dissipate or return it; root cause may be ramp settings, braking hardware, DC-bus feedback or machine load inertia.
Routes excess DC-link energy into braking hardware or controlled overvoltage management during deceleration and overhauling-load events.
Routes incoming three-phase supply through protection, rectification, precharge and DC-link storage before the inverter stage is allowed to run.