Burning wires at the neutral bus?

[Lobster Monster]

I just noticed a burning platic smell in the cabin of my 2006 240 Sundancer while hooked to shore power. Turned everything off and it went away.

Took a look behind the electric panal and the left side neutral bus was melted and the white wire to the main ac power switch was black and melted.

ALL of the wires that were fastened with hex nuts were LOOSE! All of the wires fastened with screws were tight.

Question:
Could the loose neutral wire cause the bus to melt or is it somthing else down the line?

Thanks,
John

 

[BahamasBlair]

Hi,
I would be VERY careful in correcting that situation! The loose nuts are definately part of the cause but maybe not 100% of the cause. Have you added any high amperage appliances to the boat that were not standard from the factory? Are your shore power lines melting also? Do they have any marks of melting around the pins? I would recommend you have a qualified marine electrician inspect the entire AC system on the boat, from the shore power connection all the way to the main appliances. I wouldn't cut back the melted wires and add new wire to make the connections. Replace the entire wire run with new wire and for heaven sake, don't try to reuse the bus bar. Make sure all terminals you use for repair have tinned surfaces. Don't use the el-cheapo terminals. Lock nuts on every bolt for sure.
BE CAREFUL.

 

[Bodkin Creek George]

I would say without a doubt that the loose connections were the main part of your problem. Checking the integrity of electrical connections at junction boxes should be part of your regular maint. and should be done once a year. I have worked on high and low voltage control circuits all of my working life and the first thing a good trouble shooter does is check for loose connections. Good luck and work safe.
George

 

[fc3]

The loose connection was probably the problem. The new problem is that the connection of the burned wire should not be trusted. The end has to be cut to remove the burned insulation and a new ring, not spade, terminal properly crimped onto the wire. The terminal block should be carefully examined and replaced if the contacts are not clean, shiny, and bright.

Best regards,
Frank C

 

[Lobster Monster]

Thanks guys, I'll be taking it back to the dealer to have it checked out.

Another reason I posted this picture and question was to make people aware of the situation, without lock nuts, it could happen to anyone!