Park Model/mobile home Intermittent voltage drop

[Ken Walker]

Hi, hoping someone can help with this as it has me stumped.
Occasionally there is a voltage drop from 240v to 120v at the service panel and will only return to normal after I turn off and on the outdoor feeder circuit breaker.
The total load is only 13A, no circuit breakers are tripping and there is no ground faults.
I have checked all outlets and circuit breakers, all connections are tight and I have isolated circuits one by one but the problem still persists.

 

[readydave8]

Intermittently bad breaker, replace it

 

[ptonsparky]

Is the voltage drop on the line and/or the load side?
Have you checked the voltage drop across the breaker? Line to load. Not line to line.

 

[Ken Walker]

Intermittently bad breaker, replace it

Thanks. I will give that a try. I found yesterday that there was a water leak under the trailer which soaked the connecting cable, I doubt if that would penetrate the insulation but I have it drying out.

 

[Ken Walker]

The voltage drop is on the line side. I have checked the voltage drop and did resistance check on the breaker which checked out OK. As readydave8 said it could be an intermittent fault on the breaker so I will change that out. Found that incoming wire was soaked due to a water leak so I have that drying out and up to now there has been no VD in the past 24 hours. I doubt if the water penetrated the insulation but I suspect the leak has been going on for at least a month

 

[hillbilly1]

If the main breaker plugs onto a buss, could be a burnt buss stab/breaker connection. Do the fall of potential test that @ptonsparky suggested.

 

[ptonsparky]

Damp or wet conductors don't cause intermittent power.

The drop is on the line side? Are you checking on the wire itself or the breaker lugs?

 

[hillbilly1]

Hi, hoping someone can help with this as it has me stumped.
Occasionally there is a voltage drop from 240v to 120v at the service panel and will only return to normal after I turn off and on the outdoor feeder circuit breaker.
The total load is only 13A, no circuit breakers are tripping and there is no ground faults.
I have checked all outlets and circuit breakers, all connections are tight and I have isolated circuits one by one but the problem still persists.

That is definitely a sign of a bad connection at the breaker or the buss it’s plugged into. When it is turned off, then back on, the connection is remade.

 

[readydave8]

If the main breaker plugs onto a buss, could be a burnt buss stab/breaker connection. Do the fall of potential test that @ptonsparky suggested.

Yeah I thought about burnt stab but figured if so, he would see it when he changed the breaker

 

[hillbilly1]

Yeah I thought about burnt stab but figured if so, he would see it when he changed the breaker

Re-read it, I don’t think he has changed it out yet, he said he was going to, or did I miss something?

 

[Another C10]

The voltage drop is on the line side. I have checked the voltage drop

If by line you mean upstream of the main disconnect downstream the meter, I'd focus more on that section.

The utility transformer, the meter connections and the connections to the distribution bussing.

 

[Another C10]

I found yesterday that there was a water leak under the trailer which soaked the connecting cable

If the connecting cable your referring to is the upside of the meter than that could very well be the culprit. all it takes is a pinhole opening on the insulation to bleed out.

 

[ptonsparky]

Moisture or water dripping on conductor insulation is not going to cause the grief described. It would need to migrate to the connection itself. For some odd reason I believe the breaker is above the wet cable.

 

[Another C10]

Moisture or water dripping on conductor insulation is not going to cause the grief described

True not likely from dripps, but soaked was the keyword, I figured maybe that line he referred to may of been buried or laying on the ground in a puddle.