Burnt Circuit box

Yup, it looks like the larger neutral wire, the one that connects the bus to shore power had loosened. That caused the other neutral wires to lose connectivity. Added resistance made added heat and that is the result you see.

Strip wires back to clean copper. Remove and replace the bus bar.

Double post.

I check all my 120VAC connections on a yearly basis. Did find a couple loose connections.

And by the way where did the link to post a picture come from?

this is the box if I did it right. The air conditioner neutral burned in two. Shows lots of damage

Jeff

ALmost happened to me. Led me to a sort of a not joke.

Many RVers have a few screws loose.. WHEN those loose screws are the ones that attach the wires to the neutral bus on your power center... Well, you know what happens then, You saw the result with your own eyes.

Also check all the other wires (Do this while not plugged in or running generator).

Other places I have found loose screws includ the shore plug, shore cord outlet (if detachable) and RV inlet (if shore cord detachable)

I have not found loose wires in the auto transfer switch but then I've only worked on one and that was a warranty replacement by a competent dealer tech so I'd guess he re-tightened (Well for a fact I know he did) when he replaced the original. Do not know if the original was properly tightened or not.

Loose connections cause higher resistance. And higher resistance causes heat. Many of my hot, neutral, and ground wire connections were not tight in my load center from the factory. Something everyone should check.

ANYTHING that overheats a tin plated aluminum buss or lug causes the tin plating to dissipate. Straight copper to bare aluminum is a recipe for disaster. Please follow bemerphile1's advice and replace any and all aluminum connectors that have overheated. Tin plated copper to bare aluminum is OK but bare copper to bare aluminum is a ticking bomb. Even NaLox (cosmoline) cannot stop the aluminum surface from degenerating to aluminum oxide a horrible barrier to electricity. I wish folks would understand this better :(

Cause and effect;
Loose connection causes arcing,
arcing causes heat,
heat causes melted insulation and burnt wires.

Word of warning, it probably caused damage to the neutral buss and should be replaced.

If I'm understanding your post correctly (it's a bit confusing with A/C meaning both Air Conditioner and Alternating Current), then yes, it could.

The loose connection has a higher resistance, and gets hot. Assuming it's a bad connection at the distribution panel, the heat gets conducted via the neutral bus bar to all the other connections, making them hot (but not as hot as the one for the air conditioner). Fun times ensue.

I would probably replace the bus bar and strive to reconnect the wires back where they are not obviously heat damaged. It may be hard to get sufficient slack in the wires. Bus bars are neither very expensive nor difficult to find at electrical supply houses.