1336 Force RMS Fault - 02055

I have a customer that is getting an intermittent nuisance "RMS Fault" (code 02055). Looking at the manual, this is a configurable fault from the velocity processor (speed regulator), but there is no descriptive detail anywhere that I can find. The app is a position regulated rider roll on a small rewinder. It is happening when the roll is just starting to build, so the drive is spending a lot of time at zero speed - if that helps.

I can reconfigure this as an alarm, but not knowing exactly what it is, I hesitate to make the change. Any clues would be appreciated.

Knowledgebase article:
https://rockwellautomation.custhelp.com/app/answers/detail/a_id/21990

The RMS Fault F02055 is a configurable fault in the 1336T Force drive. When this fault is set to enabled, the fault is issued when the DC bus CT (Current Transducer) senses leakage current of 2 amps or more. As it is quite common for IGBT inverters to produce at least this much current to ground as common mode current due to capacitive coupling in the motor cable(s). Therefore, it may be necessary to disable the fault to prevent nuisance trips.
You can disable this fault in two ways:

1. Detection of the 2-amp leakage condition can be completely disabled via Parameter 89 [VP Warning Configuration Select]. When bit 7 of this parameter is cleared, the leakage will be reported as neither a fault nor a warning.
2. If it is desired that the drive indicates the 2 amp leakage condition with a warning but not trip, bit 7 must be set in Parameter 89 and cleared in Parameter 88 [VP Fault Configuration Select]. After making any parameter changes, an EEPROM save operation must be performed for the changes to be stored to non-volatile memory.

And just to beat a dead horse a little more, it's time to start thinking about your migration plan for that drive...

Much embarrassed for not checking the KB, but these drives are so old I doubted I'd find anything.

We've already quoted new drives, but it will probably take a catastrophic failure before they move on a replacement.

Thanks a million.

WinderGuy said:

...

We've already quoted new drives, but it will probably take a catastrophic failure before they move on a replacement.

Click to expand...

Not an uncommon response unfortunately. It's kind of like saying "I'll call an ambulance when my heart stops beating...".