2009 Roo 19: Burned wire under banquette- help identify?

[scottatx]

My first post- hello everyone!

Can anyone help me identify what this white wire is under the front side of the banquette? Looks like 110v romex-style wire. It's burned and corroded :/

The site isn't letting me upload a pic, maybe I'm too new. Will try and post somewhere else and link it here!

Thanks!

[scottatx]

Here's a pic... the burned wire is laying on the ground and coiled, looks like it's coming from the water heater and runs behind the water filter along the wall heading towards the fridge (rear) side of the trailer. Any ideas?

[MOD Guy]

The only thing in that compartment that is going to use 110 romex is the water heater (which would be a gas/electric water heater. Doesn't look good.

[scottatx]

Mod guy: thanks, that's helpful. You can see there is a second romex line that's not laying on the floor and not burned (looks newer). I wonder if there was a problem and they repaired with a new feeder but never removed the old one? Or are there be two wires from the factory?

[MOD Guy]

The WH should only have one wire. You need to trace each wire to see where it goes. The other wire may feed over to an outlet, I can't tell by the picture. If the good wire feeds into the WH, then the burned wire should not be corrected to the WH. If they replaced a burned wire with a good wire, I would think they would have pulled the burned one out. The new wire would have had to be finished thru the same route as the burned one.
Check to see what both wires are connected to, and you should have your answer.

[scottatx]

Thanks! I don't have much history on this- it was a trade in that I just bought from the dealer. Does that pex setup look factory? Almost looks too nice. Wondering if there was a major problem with the water heater and it was replaced by a service shop after the melted wire issue...

[MOD Guy]

The PEX looks as good as the set up in my unit.

[scottatx]

So upon closer investigation, you're spot on. The burned wire goes to the outlet the hot water heater is plugged in to. The "new" wire goes to an outlet on the bunk wall that isn't factory.

Any idea what's involved in running a new feeder line for the hot water heater? Where does that hwh line feed from? Still trying to figure out where the main power distribution is on this thing...

[MOD Guy]

The water heater should have a junction box that the wire goes into. the box should have a removable cover, open it and you will see the wire connections.
The wire should run directly to the fuse/breaker panel/converter. it should not junction anywhere in the run.

The fuse/breaker panel/converter is probably going to be a brown box, located in a lower cabinet, with a drop down door panel that covers the breakers and fuses. This box also has a cooling fan. When enough of a 12volt load is placed on the system, the fan will kick on to help cool the converter. This should help you Id the box location (mine is located under the Ref).

With the camper unplugged, you can remove the screws to the box cover, and remove the screws that hold the box in place. On the back are ALL the electrical wires in the camper.

You need to figure out why the wire burnt. Replacing it is not a guarantee that the same thing won't happen again. It might have been caused by a short in the element, which can happen if the electric is left turned on when the water heater does not have water in it. There is usually a small (hard to see) switch behind the WH access door on the exterior. You may need to remove the element and check to make sure it is not toast.

Good Luck.

[Bmbrady77]

A burned through wire usually indicates one of two problems

Loose or intermittent connection, which can cause quick spikes in current on the wire that happen too fast for the circuit breaker to catch... Or

Someone installed too big of a circuit breaker and the circuit was over amped by a shorted element or bad connection. You should have a 15A breaker on the water heater if it is a standard rv 6 gallon.

Either way, the burned to wire is the symptom of the problem, not the cause. You will need to find the root cause before you replace the wiring.

[scottatx]

Thanks. Taking it in to shop this week. Repair guy on phone said that wire overheating can happen sometimes if element was badly corroded and someone turned on heater without water in tank. Not enough draw to trip the breaker but enough sustained draw to overheat the wire. Gonna check everything out and replace the melted 14 gauge with 12 gauge.

Thanks everyone for the quick and detailed responses!!

[Bmbrady77]

Not sure that would be a good idea.

A 14/2 Romex can handle sustained current draw of up to 15A without overheating. Think about it. It's protected by a 15A circuit breaker. Why would the circuit only trip if the current goes over 15A, but the wiring can overheat and become a fire hazard at less current?

As I said before. The wire is symptom. Putting in a 12/2 on a circuit that is problematic is treading on dangerous ground. It's the equivalent of putting a shorting bar on a fuse block.

[Herk7769]

Originally Posted by Bmbrady77

Not sure that would be a good idea.

A 14/2 Romex can handle sustained current draw of up to 15A without overheating. Think about it. It's protected by a 15A circuit breaker. Why would the circuit only trip if the current goes over 15A, but the wiring can overheat and become a fire hazard at less current?

As I said before. The wire is symptom. Putting in a 12/2 on a circuit that is problematic is treading on dangerous ground. It's the equivalent of putting a shorting bar on a fuse block.

Upgrading the wire to 12 GA is a bad idea IMO as well. Fix the problem and not the symptom.

Replace the wire; check the connection at the breaker for security; make sure there is no damage to the duplex outlet (replace the crappy RV type with a good quality 15 amp home store duplex) and replace the heater element with the correct 110 volt AC part.

Also check the power cord from the water heater to the duplex. If the wire burned and it was the element (I for one doubt it - more a loose connection in the duplex outlet box is my guess), that cord should also show signs of high temperature.

[scottatx]

Agree... the plan is not just to replace the wire and hope for the best Service guy is going to take a look at the whole system, make any repairs that caused the problem in the first place, and then replace the wire...