F30002Fault · Power unit (Motor Module)
SINAMICS S120 F30002: Power Unit DC Link Voltage Overvoltage
What F30002 means
The DC link (DC bus) voltage rose above the trip level, usually because a braking motor fed energy back into the drive faster than it could be absorbed.
Symptoms
Trips while the axis is slowing down, on fast stops, or when a vertical axis is lowered.
Is it repairable?
Often a setting or braking-circuit issue; repairable when the infeed or the drive's voltage sensing is faulty.
Common causes
- Deceleration ramp too short for the load inertia
- Braking resistor, Braking Module or regenerative infeed not working
- Supply voltage too high or spiking
- DC link voltage controller switched off
Safe checks
- 1Note whether the trip always happens during braking
- 2Check the braking resistor's resistance and wiring
- 3Measure the incoming line voltage
Drives hold dangerous voltage after power-off. Checks should only be done by qualified personnel, with power isolated and the DC link discharged.
Reviewed by AutomIQ repair technicians. Code and name from the SINAMICS S120/S150 List Manual.
Related SINAMICS S120 faults
- F07011Motor overtemperature
- F07900Motor blocked/speed controller at its limit
- F30001Overcurrent
- F30003DC link voltage undervoltage
- F30004Overtemperature heat sink AC inverter
- F30005Overload I2t