Why trailers burn

[Jammer]

Nearly all RV fires are of electrical origin, despite the recent attention to fridge fires (which are statistically still quite rare).

What are the failures that most commonly lead to such fires? What can we do to prevent them?

[tpi]

Question I have is the main positive cable running off the battery, where is the first fuse/breaker on that wire? How far through the trailer does it go unfused?

On the 120 volt side maybe termination of the outlets when running high draw heaters, etc.

[HiHoAgRV]

An eye opener is to walk thru an RV salvage lot, like Cowas...Lots of BBQ'd RV's from the dash and rear engine area...I don't recall seeing any trailers though...

[Stefrobrts]

I'm curious about how many vintage trailers have electrical fires caused by the old aluminum wiring. I was unable to rewire my trailer when we did the shell-on floor replacement, so when I needed a new outlet, I was told to use one made for aluminum wires. So I stole an outlet from back in the bathroom, which I didn't need, and installed it next to the new converter. But I do wonder how much risk there really is in the old wiring in my trailer.

[DougZ]

Many times during the week I go out and sit in my AS. Sometimes I wonder how it has lasted 38 years and if it will die on my watch. I have fused many of the wires and replaced a lot of the LP gas pipes to prevent this from happening. I bought new smoke detecters to install but they won't do much good if no one is in the trailer. I think my next preventive maintenance is to get rid of the old humm box and put in a state of the art unit. I sure would hate to be the one that lets this beautiful trailer go up in flames.

Doug

[2airishuman]

?? it seems u asked pretty much the same question 366 days ago...

http://www.airforums.com/forums/f48/...ler-61322.html

most of those links i posted then are still good and relevant.

mohos have primarily engine/driveline/exhaust related fires...

trailer's are either operator error ((cooking, over loaded juice, old gadgets, extension cords and so on...))

or electrical, or occasionally propane related...

these are also worth reviewing...

http://www.airforums.com/forums/f42/...eam-46861.html

http://www.airforums.com/forums/f44/...eam-56617.html

http://www.airforums.com/forums/f449...ire-62810.html

http://www.airforums.com/forums/f368...ent-38772.html

as are these...

in fact there is a SPECIFIC and long term a/s engineered fire risk noted and solutions posted here...

http://www.airforums.com/forums/f353...afe-39545.html

and discussions of 'plans' to escape, prevent, avoid...

http://www.airforums.com/forums/f161...lan-15084.html

http://www.airforums.com/forums/f161...ted-17997.html

it's all important stuff and a lot of good things have been posted...

cheers
2air'

[overlander63]

Okay, I'll tell you about a little-known fire hazard on some 1970's model Airstreams. One you wouldn't even think about. I didn't, until I set an Overlander on fire with it.
Now that I have your attention, how many of us with that era Airstream have the umbilical receptacle in the front of the trailer, behind the LP tanks? How many of them are the original, kind of grey-ish, plastic-y looking ones?
Guess what I found out.
They aren't plastic.
They're magnesium.
That's right.
The stuff they make highway flares out of, because it ignites easily, burns bright, AND YOU CAN'T PUT IT OUT!!! Water makes it much worse.
I set a trailer on fire by the simple act of cutting off the rusted-on mounting bolts with a cutoff wheel. The wheel made the magnesium hot enough it ignited. I got a nice, red flame from it.
You never saw somebody move as fast as i did running inside the trailer, throwing aside the gaucho cushions, nipping the smouldering wires off it, and kicking it outside the trailer, where it continued to sizzle and spume.
After my heart started beating again, I called the boss over, showed him the flaming plug, and gently misted a small amount of water on it. It flared up immediately, it's good it wasn't still on the trailer, or it would have become an aluminum marshmallow.

[wkerfoot]

Terry,

Are the new ones the same construction?

Bill

Originally Posted by overlander63

Okay, I'll tell you about a little-known fire hazard on some 1970's model Airstreams. One you wouldn't even think about. I didn't, until I set an Overlander on fire with it.
Now that I have your attention, how many of us with that era Airstream have the umbilical receptacle in the front of the trailer, behind the LP tanks? How many of them are the original, kind of grey-ish, plastic-y looking ones?
Guess what I found out.
They aren't plastic.
They're magnesium.
That's right.
The stuff they make highway flares out of, because it ignites easily, burns bright, AND YOU CAN'T PUT IT OUT!!! Water makes it much worse.
I set a trailer on fire by the simple act of cutting off the rusted-on mounting bolts with a cutoff wheel. The wheel made the magnesium hot enough it ignited. I got a nice, red flame from it.
You never saw somebody move as fast as i did running inside the trailer, throwing aside the gaucho cushions, nipping the smouldering wires off it, and kicking it outside the trailer, where it continued to sizzle and spume.
After my heart started beating again, I called the boss over, showed him the flaming plug, and gently misted a small amount of water on it. It flared up immediately, it's good it wasn't still on the trailer, or it would have become an aluminum marshmallow.

[overlander63]

Originally Posted by wkerfoot

Terry,

Are the new ones the same construction?

Bill

No, the new ones are aluminum or pot metal. Non-ignitable. The only plastic ones are pretty obviously black plastic. Now you know why the fire department was at the shop in Riverside a year or so ago...

[Zigidachs]

We receive our new AS next week! Hooray!!

As with our fiver we will carry an "extra" ABC extinguisher on the inside under the sink, and another stored on the outside compartment, probably on the side of the AS.

I certainly will watch for the hot wire from the battery system to the main jack, and enclose it if necessary.

Great thread. Thank you....Zigi

[utee94]

Originally Posted by overlander63

until I set an Overlander on fire with it..

Ummmm... Terry...? That was a CLIENT'S Overlander, right????

[Frank's Trailer Works]

Originally Posted by Stefrobrts

I'm curious about how many vintage trailers have electrical fires caused by the old aluminum wiring. I was unable to rewire my trailer when we did the shell-on floor replacement, so when I needed a new outlet, I was told to use one made for aluminum wires. So I stole an outlet from back in the bathroom, which I didn't need, and installed it next to the new converter. But I do wonder how much risk there really is in the old wiring in my trailer.

considering the aluminum wiring was only one year, very few due to aluminum wire.

[aircooled4]

The aluminum wire in my 67 is just fine...Im not planning on replacing it either. Im NOT running an high demand appliances in it either...

[overlander63]

Originally Posted by utee94

Ummmm... Terry...? That was a CLIENT'S Overlander, right????

It was a '77... Looked like it had been dredged up out of the bottom of Lake Elsinore...

[overlander63]

Originally Posted by 62overlander

considering the aluminum wiring was only one year, very few due to aluminum wire.

Originally Posted by aircooled4

The aluminum wire in my 67 is just fine...Im not planning on replacing it either. Im NOT running an high demand appliances in it either...

I've seen aluminum wiring on a '68 Overlander, so it looks like it was at least part of 2 years.

[lewster]

I've seen a few fires recently and worked on one that the owner caught just in time. In the trailer case, the battery was connected to the trailer thru a DC circuit breaker, but a cheap one (not the marine type as it should have been).

The wiring from the battery to his DC power center/converter ran up along the trailer frame and was not wrapped in wire loom and was not firmly attached to the frame as it should have been. In his travels, he actually rubbed the insulation from the hot lead right along the frame rail due to excessive play in the wires and created a welding action from the power in his battery that fused the contacts in the DC breaker AND in his mechanical battery disconnect switch creating a direct DC pathway to his frame and a dead short thru the negative bus bar and frame.

He smelled something burning and was able to remove the positive lead from the battery just before the wiring ignited! I had to remove his belly pan and run 30 feet of new power wiring to the DC power center, replace the entire fuse block, converter and a bunch of other ancillary wiring. ALL of the insulation from his ground wires was burnt or melted away from the copper. NOT PRETTY!

Then just a couple of weeks ago, a 2010 Marathon Prevost ($1.6 MILLION) burnt in the engine bay, destroying the entire rear section of the coach. Luckily, these coaches have a very stout fire wall between the engine compartment (Detroit Diesel 600 HP engine) and the rest of the coach, and that is what saved the forward section of the coach. We think that his auxiliary battery charging system (the one that kept the engine batteries fully charged while on shore power) malfunctioned or was improperly connected to his batteries (some were 12VDC and others were connected in series for 24VDC), overcharged the batteries causing them to outgas (they were inexplicably liquid cell batteries!) and the hydrogen sulfide being emitted ignited and literally blew up the remaining batteries. It was very quick!

Then there were a couple of fridge fires (BOTH Norcold 1200 LRIM models that are now under a retrofit recall) which totally consumed both motor homes. Not pretty either!

Moral of the story........be sure that you have the proper circuit protection on your batteries and their charging systems. I prefer either class T fuses that have a very high resistance to being fused together in emergency situations, ANL type fuses which are not quite as stout as the class T variety, or a quality marine (Blue Sea Systems) DC circuit breaker. All of these protection devices should be placed in immediate proximity of the batteries.

And not to alarm you, but your Airstreams use the same type of cheap DC circuit breaker that fused together in the first tale of the trailer fire. Check out the poor excuse for a wiring bus in the front of your newer trailers and you will see the little plastic and copper DC circuit breakers in use. They fit very neatly into their proper little holders, but after seeing how easily they can have their contacts fused closed, I would immediately replace them with a higher quality circuit protection device.

One good point is that Airstreams are wired more securely than the SOB trailer that had the incident, but it would still bother me..........A LOT!!!!

[tpi]

Do you think a big 100 or 150 amp fuse right at the battery would be a good idea?

[Stefrobrts]

Originally Posted by overlander63

I've seen aluminum wiring on a '68 Overlander, so it looks like it was at least part of 2 years.

It's been a long time (2006-ish) since I did my electrical, but I'm pretty sure it was aluminum.

[NevadaGeo]

[QUOTE=overlander63;953224] how many of us with that 70's era Airstream have the umbilical receptacle in the front of the trailer, behind the LP tanks? How many of them are the original, kind of grey-ish, plastic-y looking ones? They're magnesium. That's right.
I set a trailer on fire by the simple act of cutting off the rusted-on mounting bolts with a cutoff wheel. The wheel made the magnesium hot enough it ignited. I got a nice, red flame from it.

Umm, 70's, old gray plastiky umbilical end that likes to come loose...is Magnesium, the matchless hunting fire starter? Thanks Overlander for the heads up!!! Okay, what's a good replacement? This will be also be a good time to thoroughly examine the whole umbilical.

[overlander63]

For those interested, here is a picture of the "flammable" connector: