Teco Vfd

Line reactor has nothing to do with OV. Anyway, years can go-by with sub-optimal VFD settings, and then something happens that reveals it. Like a voltage dip that can only be detected by light dimming (lol), that for example triggers a normally unused emergency stop situation, with too steep braking, no or moderate OV protection, braking resistor disabled, etc. Because failed 1 year old bulk capacitors or other hardware failure possibility for this behavior is less likely. S.M.

Have you tested the brake resistor?

I'm going to ask the stupid question... has your load changed at all... this can include anything IN the load side (bearings, shafts, etc)... anything that may have provided a passive braking effect previously.

Of course, the lights dimming is a pretty sure sign of an issue with the underlying power system... in which case all bets are off

Matt, better check brake resistor and it's connections. If you ramp down or coast to stop faster than before you may need more brake resistors for the back EMF. I had to put two on our 75KW Teco.

By george i think i got it! I found a bigger capacity brake resistor with less resistance and in stalled it this morning (4:30am) and so.far its been running (currenr time os 8:50 am). I do notice its.putting out less volts dc since i in stalled the different resistor.