I went out to my shop to turn the lights off just now; the programmable switch had lost its memory due to a prolonged power outage. To my surprise the switch box was blazing hot. The picture below is what I found inside. Needless to say this scared the wits out of me. I've powered off the circuit to think about what to do. I use the switch every day and have never noticed it being hot before.

In theory the circuit should not be overloaded. I have 12 two-bulb T5HO fluorescent fixtures for light in the shop. at 54 watts/bulb that should consume 12 X 2 X 54= 1296 watts. The 15A circuit should be able to support safely 80% of 15A or 0.8 X 1800 watts = 1440 watts continuous load. The overhead lights are the only load on that circuit.

In practice the wire nuts are melting!

Any insight as to what's happening here? Obviously I could split the lights onto two breakers, but that would be a pain and they really should be safe as-is.

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