Electrical system has gotten hot

Usually this is caused by a loose connection that heats up and melts the wire insulation and plastic near by. Was the bubbled wire for an AC unit?

This is the 120 volt AC side, not the 12 volt DC, right?

Are you set up someplace, camping, A/C cooling the coach, water heater on, etc?

Using Shore Tie, or Generator?

What Voltage do you have?

If you're on Shore Tie, can you verify it's wired correctly?

Done any electrical work lately, meaning before this problem?

Can you find the connection where the flexible shore tie meets the household wire in the coach?

Is the shore tie connection to the pedestal good? Same within the plug?

Got any pictures? If you can't post them, send them to me and I'll try to.

j-d,

Give me a second and I'll try to post a pic...I am connected to a 20 amp plug at our church building (have done this for the past 5-6 years without trouble). I have 120 volts at the outlet and am running the fridge on propane. I have 117-119 volts at an outlet in the camper. Installed new breaker and the 30/20 one still overheated, could even see a little smoke. Turned AC off...

Tried running the genny with the AC on and I actually saw a wire spark and then a sizzle from behind the bar next to the insulating plate (which it is barely connected to now).

I have run the AC on a regular 20 amp circuit before and have always been very careful about not running anyhting else.

I cant figure out how to post pics - can I email you?

Click For Full-Size Image.

Thus pic should be rotated clockwise, but you get the picture...

Click For Full-Size Image.

When I first got in here after noticing the smell, the bottom white wire was practically broke off - it may have been completely off, but it came apart easily. I reattached it to the bar and tightened it down. The next wire up is a big neutral wire for the AC and it's badly discolored (I tried to just get some tape over it). When I went to loosen that bolt to try and remove the wire the whole bar twisted loose from the black insulating mounting plate, so that's still loose.

I am planning to replace this whole bar and plate tomorrow...but I'm still not sure why things got so hot to begin with???

I'm just now trying to figure out if it's alright to plug the coach in at all (NOT using the AC), just so we can run a fan...

I would avoid using the 120 volt RV system until the neutral bus bar is replaced and the wiring cleaned up properly. Run an extension cord into the RV and plug your fan into that directly.

Most likely the root cause was a loose, and so high resistance, connection to the bus bar. It is a good idea to check that everything is properly snug every now and again; things can tend to vibrate loose over time. It is good you caught it before anything more serious happened.

Loose connection, corrosion and excessive loads come to mind. But low voltage leading to increased amps seem likely. Is the church plug a 20A plug on a dedicated CB? Most house circuits have multiple 15A plugs on a 20A CB.

In addition to other posts sustained loads should be limited to 80% or 16A for a 20A plug. Regardless you are pushing your luck on a 15A or 20A plug with any heavy load like A/C or HW etc.

I would not use AC until the neutral block is fixed and clean not over heated wires are connected. Your picture suggests you will need insulated butt connectors to extend the wires.