Applicable Systems
EFC
FEX
FEI
HNC
Symptoms
Power choke connection fault. The drive has detected a problem with the power choke (DC link reactor) connection. Current ripple may increase, stressing DC link capacitors.
Possible Causes
- Power choke wiring loose or disconnected
- Power choke winding open circuit
- Choke temperature sensor (if equipped) indicating overtemperature
- Choke terminal corrosion causing high resistance
Troubleshooting Steps
- Step 1: Inspect power choke connections at drive terminals
All connections torqued to specification; no loose terminals - Step 2: Measure choke winding resistance
Winding resistance within specification; no open circuit - Step 3: Check choke temperature (if temperature sensor equipped)
Temperature within rated range; no overheating indication - Step 4: Replace power choke if winding is open or temperature is abnormal
New choke connects without fault
How to Reset
1) Power off. 2) Inspect choke connections. 3) Measure winding. 4) Replace if defective. 5) Reset fault.
Frequently Asked Questions
- Q: What does the power choke do?
The DC link power choke reduces current ripple in the DC bus, protecting capacitors and improving power factor. It is standard on larger drive models.
- Q: Can I run without the power choke?
No. The power choke is essential for proper DC link operation. Running without it will cause excessive current ripple and premature capacitor failure.
Source: Rexroth IndraDrive HCS/HMS Fault Code List, Bosch Rexroth AG
Category: PLC & VFD