Applicable Systems
EFC
FEX
FEI
HNC
Symptoms
The drive trips immediately. The error display shows E-1007, indicating an output short circuit. The drive has detected a short circuit condition on the motor output.
Possible Causes
- Short circuit between motor output phases
- Short circuit between output and ground
- Motor winding short circuit
- Drive output IGBT module short circuit
Troubleshooting Steps
- Step 1: Disconnect the motor cables from the drive output
Isolate the drive from the motor - Step 2: Measure resistance between each phase at the drive output
No short circuit at the drive output terminals - Step 3: Megger the motor windings and cable
Motor and cable insulation are within spec - Step 4: If the short is internal to the drive, it needs service
Drive requires service if output short is confirmed with cables disconnected
How to Reset
To reset: 1) Remove the short circuit (repair or replace motor cable or motor). 2) Clear the fault. 3) If the drive output is internally shorted, contact Rexroth service. Caution: Never reset a short circuit fault without fixing the root cause.
Frequently Asked Questions
- Q: How do I find a short circuit in motor cables?
Disconnect the cable from both ends. Use a megohmmeter at 500V to measure insulation resistance between each pair of phases and from each phase to ground. A healthy cable shows megohm-range resistance. Near-zero resistance indicates a short.
- Q: Can the drive output stage be shorted without an external short?
Yes, IGBT module failure can cause an internal output short circuit. If the E-1007 fault persists with motor cables completely disconnected, the drive output stage is damaged and the drive must be serviced.
Source: Bosch Rexroth EFC Drive Manual, 2023
Category: PLC & VFD