I have to install a new AC compressor unit outside, but it will be 35 feet from this old disconnect. I want to use the box as a junction to run new wire through conduit to the locations of the new disconnect. The old box was rated at 50A and the new unit only need a 40A breaker, so the rating is ok. #8 wire will be used and there is #6 run to the disconnect. If anyone is wondering, yes there is already a new 40A breaker in the breaker box

My concern is there is a spot between one of the line connections that indicate overheating. A pic is attached. The entire rest of the box is in great condition. Should I be concerned with this spot that was heated and looks melted, or is it ok to use?
I think it got overheated when the old unit seized.

  • once a bad contact it remains bad contact
    – Traveler
    Apr 14, 2023 at 1:01
  • There is a wire nut that will join a #6 to a #8. I wouldn't trust myself to use it, but maybe with some practice on wire off-cuts this would be a good option inside this box. The alternatives are a lot more expensive.
    – jay613
    Apr 14, 2023 at 20:59

2 Answers 2


It appears to be junk as a disconnect, but since you only need it as a junction box (it's too far from the compressor for a new disconnect, and you mention a new disconnect) then ignore the fried internals and make your junctions without them.

Of course, the economics may well be such that a new similar disconnect might cost a lot less than some other means of just joining the wires - I think my 60A units (running 15A circuits to devices using just over 10A) were under $10 each. There wasn't a smaller, cheaper size.


I would stay away from those contacts. Bakelite, the plastic probably used there, needs a lot of heat to melt like that. That heat could very easily anneal the contacts below it and weaken them. Those disconnects are really inexpensive and a cheap way to connect wire so you could replace it or just use it as a junction box.

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