Junior Member
Posted February 9, 2022
Pro Subscriber
Anyone have experience with these 4160V vacuum contactors? Having issues with the pickup coils. As found coils were at 0.2 ohms, manual calls for 9.6 ohms each (2 in series). Applied 110VDC per manual to known good coil and seemed to have burned that one up too... Haven't been able to find any discussion on this topic.
Junior Member
Posted February 16, 2022
Pro Subscriber
Turns out the free-wheeling diode in parallel with the close coil had shorted, the 0.2 ohms I read in the circuit was the short across that and not the coil itself. Advice for the repair: Customer ordered new coils so I did end up replacing them anyways. The adjustments for the mechanical latch/ Trip latch assembly and the aux switch are very sensitive, I followed the replacement procedure per the manual but its fairly vague and I ended up with substantial coil chatter. Trick ended up being to C-clamp the contactor as tight as I could without damaging the case and making all the adjustments tight against the feeler gauges. Ended up going about .006" over on the mechanical latch adjustment as the .015" measurement didn't work. Anyways, I know its probably a one off but this information would have saved me some time had I found it on here.
