I was awakened by a strong electrical burning odor around 2:am. The inside of the RV Travel Trailer was filled with smoke. The smoke detectors seem to be working, however, they didn't go off that night.I first got everyone out of the RV (wife & cat) and then unplugged the unit from the outside 30 amp plug-in. I then disconnected the battery and moved our mattress to another location and went back to sleep.The next day I investigated the source of the smoke and found this:It was later determined (according to an RV repair shop) that the reason for the burned wiring was because either one or two of the wires on the neutral bus may have come loose creating additional heat which in turn caused this problem.The shop claims that it is a good idea to periodically check to make sure that the screws on both buses (Neutral & Battery) connecting the wires. Apparently the bus will expand and retract some from the heat causing the screws to loosen over time and that the screws should be checked at least every 6 months.Now I'm no electrician so I am just following procedure. If this is true as far as checking this every so often, then I would like to post this information to warn others.

Has issues with several receptacles in my house not working correctly and voltage swings. Found that the ground wire had shorted on the buss terminal and was no longer attached. Because the screw was also melted, I moved it to an extra screw and everything has worked since.

Rascally Road Warrior wrote:...either one or two of the wires on the neutral bus may have come loose creating additional heat which in turn caused this problem.The shop claims that it is a good idea to periodically check to make sure that the screws on both buses....loose/bad connections cause arcingarcing causes heatheat burns wiresI've never seen it happen on a neutral buss, it is typically a hot/power wire that overheats. Were you plugged into reversed polarity wiring?

Yes, temp swings from being stored outdoors, vibration from the road, all contribute to terminals becoming loose. A loose connection creates resistance which creates heat as you noted. Good thing you caught it when you did. Betting that the toasted wire went to the a/c? Usually hi-amp draw units like a/c, toaster, etc, are more prone to this. Can also happen on the 12v side of inverters where you have a high amp draw.I would say check every 6 months if you travel a lot, beginning of every season for most folks.

beemerphile1 wrote:Rascally Road Warrior wrote:...either one or two of the wires on the neutral bus may have come loose creating additional heat which in turn caused this problem.The shop claims that it is a good idea to periodically check to make sure that the screws on both buses....loose/bad connections cause arcingarcing causes heatheat burns wiresI've never seen it happen on a neutral buss, it is typically a hot/power wire that overheats. Were you plugged into reversed polarity wiring?No, it's not. In a 30A service, neutral is a current carrying wire and carries the same current as the hot leg. I have seen many burned neutral wires in marina power pedestals that burned because the wirie used for the neutral feed was undersized and overheated.

Thanks for posting! I just had that happen with the GFI.I sure was never told to check and tighten electrical wires regularly, that's a good tip to know.I wonder how many of those RV fires we see so many pictures of could have been related to loose wires?

Electrical Wire Fire | Good Sam Community

MEXICOWANDERER
Explorer
Jul 22, 2013
From an engineer's standpoint, here are some questions and comments...

I do not see an especially larger gauge "feeder" wire supplying the neutral bus.

System busses are aluminum that is tin plated. Aluminum to copper contact is a no-no as it causes an unsavory oxide to form on the aluminum which greatly aggravates the heat problem and may cause a runaway problem.

Copper and aluminum expand and contract at a differential rate. Thus claiming that periodic verification of junction integrity is not warranted is ignorance of metallurgy and electrical code and function.

There are copper colloidal paste compounds (I use Thomas & Betts) that can be applied to copper conductor inserted into aluminum terminals and tin plated aluminum terminals. The purpose of the compound is many fold. First it is conductive - highly so. It conducts heat. It greatly retards degradation of tin plating, aluminum and copper corrosion. And lastly in many applications, the colloidal copper compound is needed to meet code.

There are two very different types of "Smoke Detectors" for better protection I use both kinds.
tvman44
Explorer
Jul 22, 2013
Exactly why I periodically check all wires in the panel for snugness as vibration plays hell causing loose connections. :)
rockhillmanor
Explorer
Jul 22, 2013
Thanks for posting! I just had that happen with the GFI.

I sure was never told to check and tighten electrical wires regularly, that's a good tip to know.

I wonder how many of those RV fires we see so many pictures of could have been related to loose wires?
Bob_Landry
Explorer
Jul 22, 2013
beemerphile1 wrote:
Rascally Road Warrior wrote:
...either one or two of the wires on the neutral bus may have come loose creating additional heat which in turn caused this problem.

The shop claims that it is a good idea to periodically check to make sure that the screws on both buses....

loose/bad connections cause arcing
arcing causes heat
heat burns wires

I've never seen it happen on a neutral buss, it is typically a hot/power wire that overheats. Were you plugged into reversed polarity wiring?

No, it's not. In a 30A service, neutral is a current carrying wire and carries the same current as the hot leg. I have seen many burned neutral wires in marina power pedestals that burned because the wirie used for the neutral feed was undersized and overheated.
BurbMan
Explorer II
Jul 22, 2013
Yes, temp swings from being stored outdoors, vibration from the road, all contribute to terminals becoming loose. A loose connection creates resistance which creates heat as you noted. Good thing you caught it when you did. Betting that the toasted wire went to the a/c? Usually hi-amp draw units like a/c, toaster, etc, are more prone to this. Can also happen on the 12v side of inverters where you have a high amp draw.

I would say check every 6 months if you travel a lot, beginning of every season for most folks.
beemerphile1
Explorer
Jul 22, 2013
Rascally Road Warrior wrote:
...either one or two of the wires on the neutral bus may have come loose creating additional heat which in turn caused this problem.

The shop claims that it is a good idea to periodically check to make sure that the screws on both buses....

loose/bad connections cause arcing
arcing causes heat
heat burns wires

I've never seen it happen on a neutral buss, it is typically a hot/power wire that overheats. Were you plugged into reversed polarity wiring?
Charlie_D_
Explorer
Jul 22, 2013
Has issues with several receptacles in my house not working correctly and voltage swings. Found that the ground wire had shorted on the buss terminal and was no longer attached. Because the screw was also melted, I moved it to an extra screw and everything has worked since.

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