WIC contactor problem

[blukeski]

208/230v comp contractor coil burning out about every 8 weeks. power 240v 3ph w/ hot leg.coil ont hooked to hot leg.no transformer or timer. cotrols working ok, no chattering.wires look ok,no shorts.the custmer said this has been gonig on since it was installed two years ago.also their is a WIF next ot it, same control set up and ran off same power pannel.the WIF dose not have this problem.

[jpsmith1cm]

Got a phase monitor?

[750valve]

once had a lineup of wide island freezer situated hours from city doing the same thing, local contractors (our subcontractor) changed contactors regularly, eventually customer got dirty and complained and demanded we attend site and fix it. Went up and watched this comp for hours after changing out another burnt contactor, finally it got down to temp and went to cut out on LP control (no temp control, just LP cycling 48ft + crown ends) and bugger me the contactor chatteredc and nearly launched itself out of the switchboard. Turned out LP cycle control was faulty and causing chatter. In your case I'd check things like t'stat, defrost timer, LP control - something that is in contactor control circuit which is switching when you aren't on site.

Good luck finding the cause