I have two A.C. overhead cranes on the same runway (same power pickup). They have been in service for a number of years. The cranes are feed by a 600 volts 3 ph. supply. All axis are controlled by VFD or Vector drives.
Over the last year, I have had to replace the Bridge drives on both cranes...
I would like to invite comments on the value of measuring impedance on rebuilt D.C. motors. I find that the impedance value of newly manufactured coil varies substantially compared to original coils. This is due to the coil manufacturing process. Although the motors pass all other statis &...