Wondering if anyone has some thoughts on why we have been experiencing issues with the motor starter on our in house compressor. Short story we had a NEMA 4 rated around 140amps that welded two legs on the motor starter after a relatively short time (~2 weeks) and significant pitting/welding on the third leg. Checked amp draw and seemed that we were a little undersized for the load. So we bumped up to a NEMA 5 rated around 240amps more than sufficient our max draw is around 150 when building up to the pressure we need.
Did the install and set pressure switch and timers for unload and run times, went to check the contacts condition after a short time running today and we are already seeing black around two of the legs and some pitting with the new NEMA 5 starter. Oddly enough the damage seems similar, the two legs that look the worst are the same two as before with the NEMA 4 that completely welded.
I am kind of at a lose to what could be causing this. Any thoughts?
Did the install and set pressure switch and timers for unload and run times, went to check the contacts condition after a short time running today and we are already seeing black around two of the legs and some pitting with the new NEMA 5 starter. Oddly enough the damage seems similar, the two legs that look the worst are the same two as before with the NEMA 4 that completely welded.
I am kind of at a lose to what could be causing this. Any thoughts?