Power cord amperage

coshoo · Jul 6, 2016

I need a 25 foot, 120 V 30 amp power cord for my RV. Looks like 10 gauge wires will do it, but wanted to consult with the brain trust on here. What say you?

John T · Jul 6, 2016

As a past used camper dealer, RV user of forty years, and a retired electrical engineer, I can say without hesitation that what are known as and called "30 Amp RV's" (unlike some bigger rigs that may be 50 amp 4 wire) indeed "typically" use three conductor 10 gauge copper rubber covered Power Cords. Also, 25 feet is a reasonable length cord you would find on a 30 amp RV. The 30 amp 120 Volt RV plugs are 3 terminal (1 Ungrounded Conductor(HOT), 1 Grounded Conductor (Neutral), 1 Equipment Grounding Conductor)

NOTE: This assumes you need a cord for "120 V 30 amp" AS YOU STATED

NOTE: Inside the RV distribution panel YOU DO NOT BOND NEUTRAL TO GROUND, their busses are kept separate and electrically isolated and insulated off each other.

If voltage drop were an issue (some RV parks are notorious about low voltage at the pedestal) you could always use bigger wire

Sure Camping World and Adventure RV etc and others sell all you want, but I have seen good prices at Menards.

John T

Stephen Newell · Jul 6, 2016

Assuming you are replacing a cord, what size was the old one? Did you ever notice it getting very warm? I know the 50 amp cords are about double in price as a 30 amp but it would be worth the upgrade if the 30amp cord is getting hot.

John T · Jul 7, 2016

Stephen, I've used and bought and sold a ton of 30 amp RV's and I agree I've observed many many 10/3 cords run a bit "warm" if running a rooftop AC and other loads grrrrrrrrrrrrrrrrrrrr. Often the park pedestal has low voltage and/or the receptacles are worn out or loose or carboned. It would be a bit cumbersome to try and use the big fat four conductor 6 gauge 50 amp cord fit into the 30 amp 10 gauge plugs and receptacles if hard wired, they do make 30/50 and 50/30 adapters

Have a great day

John T

coshoo · Jul 7, 2016

I just bought the RV, and it came without a cord (it has a 50 amp socket, and the seller had a boat, so I suspect he just switched one cord between the RV and boat, as needed). I talked to my RV guru, and he suggested a 50 to 30 adapter at the coach, and a 30 amp cord, which I ordered from him.

Blackhole49 · Jul 7, 2016

I would just go on line or to an RV dealer and get a 30 amp cord with the correct ends. Get an adapter in case the area your using it at doesn't have the 30 amp plug. Most campgrounds have 30 and 50 amp plugs. I cary 2 25' 30 amp cords and an adapter in my RV.

BarnyardEngineering · Jul 7, 2016

Be careful with "just buy"ing something. Some supposed 30A cords are made with 12ga wire. They'll lure you in with a cheaper price.

John T · Jul 7, 2016

coshoo, thanks for the update " (it has a 50 amp socket, and the seller had a boat, so I suspect he just switched one cord between the RV and boat, as needed). "

NOW THAT CHANGES EVERYTHING!!!!!!!!!!!!!!!!! My answer bellow DOES NOT address that info I didn't have before. Boats and some RV's use a twist lock type of plug and receptacle so yes you can use appropriates adapters.

Best wishes, do it right and keep safe

John T

Power cord amperage

coshoo

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John T

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Stephen Newell

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John T

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coshoo

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Blackhole49

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BarnyardEngineering

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John T

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