Help Me Troubleshoot

[DoneItAll]

My 30 amp power cord is tripping the breaker at the campsite. Molded plug is not in good shape, partially pulling away from the cord. Outlet tests just fine. I suspected cord male plug, so I replaced it but now it still trips the breaker. Plug tests open between ground and neutral but grounded between ground and hot. Tripped the camper main 30 amp breaker but problems persists. Since it remains a problem even though I had tripped the main breaker in the camper, does this narrow it down to a bad cable leading into the camper? How hard is this to replace.

John

[ManitouF]

Glad to see and hear you are back in working order.... thank you for letting us know... good luck to you and may you have many pleasurable travels... I myself depart from Georgia on friday to see grandchildren in Oregon...

[DoneItAll]

Yes, I certainly had reversed the neutral and hot. I was so certain that I hadn't that I ignored that possibility, got out the VOM and began to make the simple error on my part much too complicated. I woke up during the night after reviewing ManitouF's post over and over in my head and rewired the plug, switching the black and white and everything works like a charm. The cheap Chinese plug that I replaced was largely a block of pot metal with wires running in and blades coming out. I should have realized that it was not as easy as I had thought to be able to see which wire was connected where.

Thanks for all of the input. If only I'd paid more attention to the very first reply. Thanks, newman fulltimer. Live and learn.

John

[ManitouF]

Maybe this will help... in your house a three prong plug has a round hole for ground. The wider receptacle blade is neutral... the narrower flat receptacle is hot... this is so you cannot put the wider (neutral prong) of a polarized appliance into the (hot) narrower receptacle. Even if it does not have the round ground plug to stop you... now the rv plug neglected to make neutral wider... but if you look at a receptacle... campground or gen... if you orient the round plug high... neutral will be to your right... to match this with your cable plug... hold with prongs facing away from you as if you are plugging in, with round at top center neutral is low and to the right... hot to the left... on your repair plug hot should be brass colored. And neutral an aluminum or silver hue.. colors can be wrong. Or both may be same color... functional orientation should get you in the right pattern...

Btw... you have pretty much eliminated the cord as being faulty ... with one or less ohms between white neutral and green ground....and the same resistance between hot to neutral as hot to ground...the charging transformer is what you are measuring the resistance of...

[ManitouF]

In your original post you describe an open (non conductive) situation with ground and neutral...and a closed (conductive) between hot and ground... this is opposite of what should be the case... neutral and ground can be conductive or bolted directly together. Black (hot) needs to be by itself...looking for an appliance to run through and find the neutral it wants and needs to complete a circuit... if hot shows conductive to ground... you have a direct short which must be eliminated... if this post followed the end plug repair... reversing hot with neutral should square you away...

[DoneItAll]

Haven't tried the generator. Camper main breaker off when resistance readings taken. Wouldn't isolate pretty much just the cord?

John

[jimh406]

I think it is unlikely it's your cord. Have you tried a different campsite or tried plugging into your generator if you have one? Are several appliances on when you plug in or are they all off?

[ManitouF]

Even if you were correct... he would close neutral white and ground green at the point he plugged in... the problem here is that hot black is finding a direct short to ground or neutral... be it the plug repair, or the cable, or black against white at any point... if his ohm check is as stated... then reversing white and black from the point of tripping breaker... is very likely the fix..

[ManitouF]

You are incorrect that neutral and ground will always be isolated at the invertor. They often land on the same lug under the same nut.

[Harvard]

The neutral (White) and ground (Green) IN THE RV should be isolated.

Neutral and Ground are connected together at the shore power distribution panel ONLY.

[ManitouF]

You had black and white reversed in your plug repair... or in the camper at other end before repair... you can have conductivity between neutral and ground. But never between hot and ground. Nor between hot and neutral... any conductivity between hot and neutral will be equal to the load resistance of an appliance you have turned on... light bulb or otherwise...

[DoneItAll]

Removed the replacement plug entirely and test resistance between the three wires. 0 (O.7) ohms between green and white, 138 ohms between green and black, 138 ohms between black and white.

John

[newman_fulltime]

black goes to the copper side white to the silver green to ground

[DoneItAll]

I'm pretty certain I matched what I saw when I cut off the old plug. I'll give that a try though and see what I get.

John

[newman_fulltime]

didyou wire the plug right?Sounds like the neutral and hot are backwards