I had a failure of a QC Charge J-Plug 40A J-1772 nozzle last week. it was purchased Aug2017 via the OpenEVSE Store, supplied as part of their "Advanced" 40A EVSE kit (assembled, in my case, by them).
More details
here and
here.
Boils down to a failed crimp on a socket-to-twin-12ga-wires connection.
At home, I'd disconnected near the end of a 1.5 hour charge session, and smelled hot plastic. First IR measurement was 200°F ! By the time I could get a picture, it had dropped a bit:
Sockets looked OK:
I opened the nozzle, and . . . uh, oh:
Fried insulation on the two black high-current 12ga wires:
It's discouraging to see fasteners installed that aren't corrosion-resistant, as I live near Seattle, and it's unreasonable to expect to only charge in dry locations when everything outdoors is wet most of the year. But water wasn't a contributing factor here (other than to accelerate the copper corrosion, as it broke down due to the heat). It's a failed crimp. I'm not trained to inspect this type of crimp connection, but I'd hazard it's possibly been overcrimped.
I replaced the nozzle and cable assy., as the bare nozzles aren't a lot of fun to replace unless one has access to the correct crimper, and while I own around a thousand bucks of crimpers and dies, I don't have this one and figured investing in more dies for a one-shot repair wasn't economical. I bought the next capacity larger nozzle & cable: 48A, as opposed to this failed 40A.
(choose "48A" from the combo box near the Cart button); $219 plus tax, shipping, etc. That's almost half of what I paid for the whole EVSE in 2017!