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Contactor cycles open/closed every few seconds during charging

I recently had an issue with my 50A OpenEVSE kit. After a few minutes of charging, the contactor would open. A few seconds later it would close. A second later it would open again... Repeat until the car threw an error and stopped trying to charge. Thermal problem? I disassembled the Packard contactor, found some scoring, burning and pitting on the actual contact pads. For now I've cleaned them up and burnished them smooth again, and so far it's been able to charge at 14A (all my car will take) for an hour. Probably a very isolated occurrence, but thought I'd report it.

 Hmm. Not fixed. At my cottage, it works fine. In my garage at home, it exhibits the problem. The only difference I can find is that the voltage at the cottage is exactly 240V, at home we have 128V on one leg, and 123V on the other, about 250V phase-to-phase. Would that do it?

Additional data:  It seems the EVSE board is triggering the contactor on and off, I see voltage on the relay connector when the contactor is closed, none when it is open.


The EVSE is likely behaving properly, it seems to be an issue with the J1772 cable, possibly moisture or a similar issue.  I'm seeing poor isolation between hot and ground, and hot to hot.  I suspect that while at my cottage the cable dried enough to mask the issue.


I have it inside again to dry, and will know for sure in a day or two.

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