Rockwell Automation AK DBU - Dynamic Braking Unit 600/690 VAC - Manual (Page 26)

2-4 Start Up / Troubleshooting
Table 2.A Possible Faults and Corrective Actions
Troubleshooting
Fault Cause Corrective Action
Heat sink Over
Temperature Heat sink temperature
exceeds maximum
rating. 1. Verify the maximum ambient temperature
has not been exceeded.
2. Check fan for correct operation.
Replace fan if necessary with fan kit
No. SK-D9-FAN1
3. Check for excess load on the DBU.
Refer to Appendix C for calculations.
Verify the braking duty cycle does not
exceed the drive(s) design specification.
4. Check for proper clearance around the
DBU.
5. Contact your local RA sales office.
DC Output
Voltage Loss Loss of DC Bus Power 1. Check 3-Phase AC Incoming Power on the
drive(s) for undervoltage or phase loss.
2. Check Fuses on DC bus input leads.
3. Check Inverter.
4. Contact your local RA sales office