I have a 240v, 48amp (60 amp breaker, 6 awg NM-B wire) car charger outside that has a disconnect inline and last night I noticed a really weird smell in the room the wires to out to the charger from. I tracked it down using my nose to the disconnect box (or the wires leading to/from it) and at this point it was pulling 48 amps because the car was charging. I inspected the area and didn't notice any melting but since it was raining I didn't want to open the box outside to look in. I lowered the amps to 32 via the car and the smell appeared to dissipate and this morning the smell was gone. I also noticed a small humming sound from the disconnect outside at the same time.
But it's rated to 60 amps. Maybe something is lose, what would cause a smell/buzz? What should I check first?
Best Answer
Both of the things you report - the smell and the hum - are very likely indications of a bad connection or bad contact in the disconnect.
Bad connections and bad contacts generate heat, the heat can damage the insulation of the wires, and even cause a fire.
I'd leave that disconnect off and if possible turn of the breaker for the circuit until it can be checked. You'll probably wind up having the disconnect replaced, hopefully the wiring can be re-terminated without replacing it.