Traveling with the 120v on

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Jammer

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Well like any RVing forum we've had innumerable threads on the topic of whether it's safe to travel with the propane on.

Curiously, considering that perhaps 10x as many RV fires are of electrical origin as are caused by anything having to do with propane, the question of the safety of running the 120v (generator, inverter) while traveling hasn't come up.  Wiring damage, often leading to shorts, is common in collisions, which is the main reason cars have fairly sophisticated fusing systems.

So, do you run with the 120v on?  Do you consider it a safety risk?
 
Statistically, the most common causes of motorized RV fires are engine and driveline related. In hot enough weather, we often travel with the generator running to power the A/C units. The circuit breaker setup in our coach is comparable to a residential system, and complies with the National Electrical Code.
 
My (whole house) inverter is always on, and the generator is on any time I need air conditioning.
 
perhaps 10x as many RV fires are of electrical origin as are caused by anything having to do with propane
Statistically, the most common causes of motorized RV fires are engine and driveline related

For many years we on the RV Forum have tried to pin down statistics that are relevant to RV fires.  Yes we know they happen, but how often.  You've both made statements that appear to be based on statistics.  Please cite your sources so the rest of us can look at them too.  I've never seen any - in 35+ years of RVing - so if you know something the rest of us don't know, please tell us where you found the information.  I for one would like to see it too and I know many other old timers here on the forum would like to see them too.  Thanks!

ArdraF
 
Regarding the "Fires of electrical origin".....

120 volt is well protected with breakers, For example the inverter in my coach is capable of about 20 amps (less actually 2,000 watts) draw more and it shuts down, the generator has two 30 amp breakers, draw that much and they go CLICK and no power exits the box.  The greatest fire danger in the electrical 120 volt system is a generator engine fire.

The greatest fire danger electrically in a motor home is on the 12 volt side of life where often wires which will seriously overheat at 20 amps are protected by 30 amp fuses.  This also applies to cars I might add.

I'm not worried in the least about the 120 volt side of life.
 
We always have the generator on when traveling.  The kids watch movies, play games and we keep cool with the air on.  Never had any problems nor do I expect any
 
ArdaF:

I don't think these are necessarily in conflict because my source is based on experience with towables where chassis-based fires aren't common.  (Hmm, another piece of food for thought for the perennial MH/TT discussions)

My source is correspondence with Andy Rogozinski, who was formerly an insurance adjuster with Caravanner Insurance, a company that operated in the 1970s and exclusively insured RVs.  They were the insurance arm of Airstream.  His situation was unique as the insurance industry no longer is organized in such a way that there are adjusters who solely work on RV claims.
 
While this is partly conjecture on my part, I believe that a goodly number of RV fires result from arc faults -- medium resistance shorts between the hot and neutral, as a result of wiring being pinched or otherwise damaged by a sharp conductive object.  Ordinary circuit breakers don't provide meaningful protection against these because they typically are not conductive enough to cause 15/20A+ of current to flow continuously enough to cause a breaker trip.  The newer arc fault breakers would help but aren't used, as far as I know, by any RV manufacturer.

This sort of thing is also a potential source of trouble with 12v circuits as well.

Another possible source of trouble is poor quality connections in high-current circuits, causing overheating.  The widespread use of insulation-displacement receptacle connections may contribute to this, as they are not as reliable as screw terminals. 
 
Agree with Jammer.
Having worked in the electrical/power field all my life, a common cause of a fires were high resistance connections at terminal strips like you have in transfer switches.
There is no over current in these conditions therefore breakers or fuses will not trip to protect.
This often started a fire and then the ionized air was conductive and went went phase to phase or phase to ground only then did the circuit trip.
To compound this further you have a platform that is constantly flexing working on the terminations.
The reason all auto, RV and boat wiring must be stranded rather than solid as you have in a house or building.
I have re-torqued the connections on my transfer switch  because the copper has relaxed a little.
High resistance connections are just as likely to show up on the DC system.
 
For me, this is a non-issue. I don't think an electrical fire is any more (or less) likely while driving down the highway than it is while parked. Granted, the electrical system damage may occur because the RV is being driven over rough roads all the time, but problem seems no more likely to show up when driving than when parked.

So I use electrical power - inverter or generator - as needed when underway. But then, I leave the propane on too.

Overheated brakes are another statistically significant cause of RV fires. Perhaps we should not use the brakes either?

Various sources of RV and fire safety information can't even agree on the number of RV fires annually (I see estimates varying from 3100 to 6700 to over 10,000!), let alone the most frequent causes.  Here is one presentation that has a bit of data and is honest enough to admit the available date is not reliable.
http://www.hdtrally.com/Presentations/2011_Fire_Safety.pdf



Edit: fixed a typo - missing letter
 
The reason all auto, RV and boat wiring must be stranded rather than solid as you have in a house or building.

That must apply to DC wiring only.  All the 120VAC wiring in our motorhome is solid wire Romex.
 
Ned said:
That must apply to DC wiring only.  All the 120VAC wiring in our motorhome is solid wire Romex.

Mine too, except for the power cord itself, and I attribute that to the need for flexibility in the cord.

I only mention the above, because that's the ONLY area of 120v wiring where I've ever had any problems.  It seems the wire nuts used to connect the stranded cord wires to the solid romex wires worked loose.  Two connections, of the three, needed to be re-done.
 
I sure wouldn't want to coil a solid wire 50A power cord :D
 
Gary RV Roamer said:
For me, this is a non-issue. I don't think an electrical fire is any more (or less) likely while driving own the highway than it is while parked. Granted, the electrical system damage may occur because the RV is being driven over rough roads all the time, but problem seems no more likely to show up when driving than when parked.

So I use electrical power - inverter or generator - as needed when underway. But then, I leave the propane on too.

I think that's sensible.  It's interesting to think about, though.

Overheated brakes are another statistically significant cause of RV fires. Perhaps we should not use the brakes either?

Perhaps RVers should move to Minnesota, where it's flat. ;)

Various sources of RV and fire safety information can't even agree on the number of RV fires annually (I see estimates varying from 3100 to 6700 to over 10,000!), let alone the most frequent causes.  Here is one presentation that has a bit of data and is honest enough to admit the available date is not reliable.
http://www.hdtrally.com/Presentations/2011_Fire_Safety.pdf

I agree that the data is very thin and, in some cases, contradictory.

The common thread in all the data that I do see is that propane isn't nearly as much of a cause of fires as the other sources, despite the relatively greater amount of attention it receives from RVers.

Another underrated source of fires is stator shorts in the generator.  I guess some newer generator controls are better at detecting these and shutting down the engine than used to be the case.
 
Ned said:
I sure wouldn't want to coil a solid wire 50A power cord :D

LOL... You might have to get one of those Power company trucks with the big wooden spools on the back to follow you around.
 
Here is one thought that I have not see posted about your 120 volt power supply.
My coach is 12 years old with about 115,000 miles on the clock.  After a time I have noticed that the ''screws'' that hold the wires in the breakers will get slightly loose.  I think this is caused by the bouncing of the coach on the road and the wires/ breakers heating up in use and cooling off when not in use.
With that In mind ,,,,,,  here is what I do....
one......  I unplug my coach from the 120 source plug in.
two.....  I take the wires off the batteries that feed my 12 volt system.
three..... I double check everything to be sure I HAVE NO POWER FEEDING THE ELECTRICAL PANNEL.
four.......  I take the front off the electrical panel after removing all the business cards, phone numbers, pictures, reminders and other misc. stuff that gets stuck on the front of the electrical box.
five.....  Standing on a piece of dry plywood, I reach inside with a flat blade screw driver and tighten the bolt/screw thingie on the end of each breaker where the wires are stuffed in. 
five A...  You would be amazed that sometimes I have turned the bolt/screw ''thingie'' as much as a ''half turn'' to get them tight.
(note***** You do not have to be Sampson too turn these bolts.  Just apply steady pressure while turning and ''feel'' for movement.....DO NOT STRIP THE THREADS)
six....  look at all the wires coming into the breakers.  Look for Burnt wires and corroded wires.  Use a good flashlight and check them out carerfully.
seven.....  Be sure that the ''inside'' of the breaker is pressed down firmly on the ''bus bar'' inside the box.  Just take your finger and press on the ''inside of the breaker'' to feel for movement.
eight.  While you have the front of the electrical panel open give everything a good ''look a round'' inside it.  Look for dead rats, spider webs, mud dobber nests and anything that should not be in there and sweep it out of the box.
Nine.    Put the cover back on the box.  replace all the pictures, notes, business cards and all the other stuff you had taped to the front.  Go outside and re hook your batteries and plug the cord back into 120 power box.
ten.......  Go inside and test everything on 120 volts.  If it all works yell  ''YEEEEE HAAAA WWWW AAA'' and get a beer and flop on the sofa and celebrate.

Remember this .........  All this advise is free and you are free to use it or not..... YOUR DECISION.....

When you see a military person, give them a warm handshake and a big hug and say THANK YOU FOR YOUR SERVICE...  They like that .......cj...
 
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