Unidrive Classic HF Trip Codes: HF82, HF83, HF84, HF88

HF82 – Large option module missing:
The trip would be expected if one of the UD7x large option modules is removed while
the Drive is powered up. If this trip occurs at any other time than the case above, then
there is a problem with either the large option module or the UD90A control PCB.

HF83 – Power Board Code Failure:
This trip means that the UD90A control PCB could not recognize the power rating of
the power PCB it is connected to.
On Unidrive Sizes 1 to 4, the trip is probably due to the power PCB in the Drive but a
problem with the UD90A control PCB could also cause this trip.
On a Unidrive Size 5 the trip is caused by either UD99 PCB or the UD90A PCB. The
interconnects between the PCBs could also cause this trip and should be checked.

HF84 -Current Offset Trim Failure:
This trip means there is a problem with the current feedback on the Drive.
On Unidrive Sizes 1 to 4, the trip is probably due to the power PCB in the Drive but a
problem with the UD90A control PCB could also cause this trip.
On a Unidrive Size 5 the trip is cause by either UD99 PCB or the UD90A PCB. The
interconnects between the PCBs could also cause this trip and should be checked.

HF88 – Watchdog Failure:
This trip can result from a faulty UD7x Co-Processor.
With power off, remove Co-Processor and re-apply
power.
Hardware Faults are typically fatal. If powering down and letting the drive sit for 5
minutes before re-application of Power does not clear the HF Fault it would require
Drive repair.

MRO Electric stocks new and refurbished Classic Unidrives. We also provide pre-priced Control Techniques repairs. For more information or to request a quote, please call 800-691-8511 or email sales@mroelectric.com.