Dead Short

[Miss Daisy]

We just took our 5th. wheel out for the third time this year, (last being 1 month ago) when we connected our 30 amp power cable to the power feed outlet on the post, it would trip the 30 amp circuit breaker in the power feed box (on the post) immediately. Even after resetting the breaker every attempt resulted the same, tripped circuit breaker. When I plugged just the power cord to the outlet, (not connected to the RV), the breaker didn't trip. Just to be sure, I ohmed out the cord, it tests good. The batteries and the 12 volt system test/work fine. Any thoughts ?

[cavie]

Originally Posted by Miss Daisy

We just took our 5th. wheel out for the third time this year, (last being 1 month ago) when we connected our 30 amp power cable to the power feed outlet on the post, it would trip the 30 amp circuit breaker in the power feed box (on the post) immediately. Even after resetting the breaker every attempt resulted the same, tripped circuit breaker. When I plugged just the power cord to the outlet, (not connected to the RV), the breaker didn't trip. Just to be sure, I ohmed out the cord, it tests good. The batteries and the 12 volt system test/work fine. Any thoughts ?

Plug in the cord with no trailer. Check voltage. Hot to neutral 120 volt. Hot to ground 120 volt. Neutral to ground no volt.

Check the pedestal. Unplug the cord. Right side slanted slot is neutral. Check it to ground. no volt. Hot is left slot. check to ground 120 volts. hot to neutral 120 volts. This is why you need an EMS.

If all this checks out the problem is in your trailer.

By "OMHED OUT" I'm assuming you checked black to black end to end. White to white end to end. Green to green end to end and got continuity on all three?

[Flybob]

Try turning a few breakers off in the RV. If you have several high use items set turned on, the combined startup current could be greater than 30A. You could also have a bad breaker as they take quite a bit of abuse.

[chaps2018]

Turn pedestal breaker off
Hook up power cord like normal (both ends)
Turn off all breakers inside rv
Turn on pedestal breaker
(If it trips again, the converter/distribution panel is the place to start looking for problems.)

If it does not trip then go inside rv and turn on breakers one at a time to see which circuit is the culprit

[Miss Daisy]

Sorry, I didn't mention that I tried it at 2 other sites with 30 amp service on the "pedestal" with the same result. I also tried it with the breakers inside the RV turned off, same result. How do I test the converter/fuse panel ? I'm no longer in the campground, nor do I have access to a 30 amp service. I do have a multimeter.

[Flybob]

Good additional info. It is possible that one of the wires on the connector on the side of the RV has come loose and caused a short. With the unit unplugged, you will need to check the back of the power plug on the side of the RV

[5picker]

Originally Posted by Flybob

Good additional info. It is possible that one of the wires on the connector on the side of the RV has come loose and caused a short. With the unit unplugged, you will need to check the back of the power plug on the side of the RV

^^This^^
We've had several reports here of the wire connections coming loose/shorting on the back side of the shore power connection on the side of the R/V.

You are going to need to access that AND trace and check the wiring from there to the distribution panel/converter before condemning the distribution panel/converter.

[TitanMike]

You've checked the cord but have you checked the receptacle it plugs into on your trailer?

Mine has a tendency to fill with water and you could have a shorted out receptacle. If you have all breakers inside the unit turned off and it still trips the breaker on the pedestal when you plug in, the converter isn't part of the equation. It should be turned off and that would leave only the wiring to the power distribution 12ov bus inside the converter enclosure.

I'd also check the back side of the power inlet receptacle for signs of shorting.

A relatively quick series of checks that would isolate your problem"

Plug in cord while not connected to trailer which I believe you've done. If it doesn't trip, then plug in, If it trips, go to the power distribution panel in the converter housing and disconnect the Black (hot) wire from the 120V buss. Put a wire nut on it for safety and then go back and reset breaker. If it remains on, you problem is in the 120 v buss that all the breakers plug into. If it trips you have a short between power distribution buss and the receptacle. My guess is the receptacle as it's been exposed to weather.

Work your way up the stream without just jumping back and forth.