wet wires

[Charlie Bob]

Service call. Customer tells me that 20 amp breaker keeps trippin.
He had another electritian look at it. guy spent two hours found 2 or three amps in circuit, puzzled he left. told HO sorry i don;t know what is causing this.
It was acting like a short, but only after some time being on. At first i thought it was an overlod.
After asking all my questions and 2 hours i found the problem.
Roof had been leaking, dripping inside outside wall, where there is a recep. Apparently getting all the wires going to it wet.
took receptacle out, disconnected cables (HO decision), problem solved.

-What kind of damage do you think water did to the romex?
-Did it create a short within the cable?
-Would the water eventually act like a conductor between them?

Keep in mind that the breaker would trip after 2 or 3 min.But before we got some rain it would trip after a couple of hours.
Breaker is not AFCI or GFCI.

 

[M. D.]

I had two similar issues both were outside receptacles and the GFCI was tripping ,.. any how the worst of the two the NM was soaked , but there was enough slack for me to strip back ,.. at about 12" back it was dry .. It would be hard to guess but rain water would not be likely to cause catostophic damage to the cable ,.. and it should dry out .

http://www.iaei.org/magazine/?p=1699

 

[ultramegabob]

you need to megger the cables, if you identify a bad cable, replace it....

 

[ptonsparky]

It takes forever for romex to dry out once it's wet and if the insulation around it is wet to, forget it. We had a customer with similar situation but with K&T. Didn't blow fuses, just energized storm door via wet insulation.

 

[Pierre C Belarge]

Abandon the existing wiring. Make sure the customer has the leak fixed. Replace the wiring.
NEXT...

 

[LarryFine]

Apparently getting all the wires going to it wet.
took receptacle out, disconnected cables (HO decision), problem solved.

If removing the receptacle fixed it, then the problem was water in the receptacle, not the cables.

Last year, I found a similar problem with a receptacle getting wet, but it was cat urine, not rain.

Yuck!

 

[Charlie Bob]

sorry Larry i didn't express myself right.
I took the receptacle out but that didn't fix the problem, the problem was in the wire itself.As a matter of fact, while checking for potential in the wires, i heard a "pop" coming from inside the wall, about 4 or 5 feet above the receptacle box. When i isolated this part of the circuit the problem was solved.

 

[PetrosA]

Sounds like a non-UL listed staple cut through the outside insulation

 

[Pierre C Belarge]

Sounds like a non-UL listed staple cut through the outside insulation

Are staples even listed?

 

[ptonsparky]

If removing the receptacle fixed it, then the problem was water in the receptacle, not the cables.

Last year, I found a similar problem with a receptacle getting wet, but it was cat urine, not rain.

Yuck!

BTDT!!! shiver shudder. Maybe they like the tingle.

 

[Kdog76]

Are staples even listed?

Check your bag of romex staples next time.

 

[LarryFine]

When i isolated this part of the circuit the problem was solved.

"I see" said the blind man.

 

[Sierrasparky]

He just left the problem for a future handyman to screw with.

 

[Charlie Bob]

the HO asked me to eliminate that receptacle and the wire causing the problem.There's no way to get to it unless you cut the wall(wire ran across studs feeding off another receptacle.) HO didn't want the wall cut.
I guess the staples could be a posibility, maybe water could cause a short circuit where the staple was. I'll never know without seeing the wire.

 

[hurk27]

or an open splice in the wall?

damaged cable from mice?

water can't get into romex unless it can get to an opening in the jacket, and even then, the insulation on the conductors inside would also have to have an opening in there insulation, for the water to cause a problem.

but water can wick up into the paper in the jacket, but even then it should not cause a problem if the inside conductor insulation is intact?