Unstable Voltage From Drive

I think we need more information.

What's a BDC fanuc, is it a GE product or something?

Also, how old is the motor and or drive?

Can you provide more information please.

Can you post details of your equipment, make/model, PLC/VFD drive?

Pleaqse describe the outcome of the telephone call that has been made on this topic to the drive supplier.

what is the load coupled to motor? if load is slipping, i mean the belt is slipping when load is too high that time also this prob comes. i experienced this in my plastic extruders

BDC likely means Brushed DC (as opposed to Brushless DC or BLDC). Fanuc is GE's Japanese partner, they make drives, motors servos and machine tool control systems.

2200RPM DC motor is most likely a spindle on a machine tool. Accepting the veracity of the testing you seem to have already done, I'd start looking at a bad connection or conductor somewhere between the drive and the motor. Always eliminate the easiest possibilities first. Next I would start suspecting the drive output devices or firing board. Fanuc has pretty much gone over to AC or BLDC now, so this is likely an older drive, it may have reached the end of its service life. Probably still serviceable, but weigh that cost against replacement, you might be shocked to discover it is rarely worth doing on small drives like this now.

Thank you for your reply,yes this is a old spindle bdc,may have come over on the Mayflower,have figured out problem or should say drive figured it out for me,drive smoked,will probably go with a bldc,alot less problems.