30 amp trailer plugged into 50 amp outlet

[TNFSolitude]

My neighbor's trailer is an older 5th wheel with a 30 amp power cord. He has an adapter 30 to 50 and has it plugged into the 50 amp receptacle. A resort handyman stated that could be a problem. His biggest draw would be a single AC. He also has a microwave. Unknown on space heater use during colder weather. No washer or dryer.
Is there an issue using the 50 amp receptacle?
He says it's been that way for years, and looks it. He said he was told it would supply a better feed to his trailer.
Does it?

[Second Chance]

No issue at all - don't know where that "handyman" got that notion. 50 amp outlets are actually two legs of 50 amps on separate phases for a total of 100 amps of service. The 30 amp RV will have a 30 amp main breaker to protect it should anything overdraw.

Rob

[howson]

My neighbor's trailer is an older 5th wheel with a 30 amp power cord. He has an adapter 30 to 50 and has it plugged into the 50 amp receptacle. A resort handyman stated that could be a problem. His biggest draw would be a single AC. He also has a microwave. Unknown on space heater use during colder weather. No washer or dryer.
Is there an issue using the 50 amp receptacle?
He says it's been that way for years, and looks it. He said he was told it would supply a better feed to his trailer.
Does it?

I don't know about "a better feed". That makes no sense to me.

Assuming the neighbor's trailer has a 30A main breaker on his power distribution panel (the one inside the trailer) and hasn't modified the OEM wiring of his camper, it shouldn't make a difference that he's hooked into a 50A outlet. If he exceeds 30 amps the trailer's c/b will open.

[Cate&Rob]

Hi Tom,

I agree with SC Rob that this is a common situation and should present no problems. The only slightly "unusual" thing about this (from a wiring perspective) is that the circuit breaker is usually upstream from what it is protecting. In this situation, the 30A breaker in the RV is "protecting" a 30A cord that is upstream from the breaker and plugged into a 50A outlet. It would take some unlikely wiring fault to draw more than 30A through this cord before the RV circuit breaker opened.

(another) Rob

[Country Campers]

I have done this plenty of times with our previous TT , it was 30 amp. Some times there were lots of folks using the 30 amp and very few using the 30 amp. Other times the 30 amp breaker at the post would trip and the 50 amp would not. The adaptor used only allows the use of 1 leg of 50 amp thru to the RV. I agree if an overload was to occur that the on board 30 amp breaker should trip , hopefully before the 30 amp cord melts.

Brian

[Jkwilson]

There can be a problem doing this. If you were to have a short in the shore power cable, the shore power connector or the wiring from the shore power connector to the breaker panel, you have the potential for overloaded wiring. All of that wiring is protected by the breaker at the pedestal. Since the wiring was intended for 30A service, but is being protected by a 50A breaker there is an opportunity for a problem to occur.

[Second Chance]

There can be a problem doing this. If you were to have a short in the shore power cable, the shore power connector or the wiring from the shore power connector to the breaker panel, you have the potential for overloaded wiring. All of that wiring is protected by the breaker at the pedestal. Since the wiring was intended for 30A service, but is being protected by a 50A breaker there is an opportunity for a problem to occur.

In this case, the 50 amp breaker would still trip - not a reason to worry.

Rob

[JCR GD]

No different than plugging a light weight lamp cord into a 15 or 20 amp plug. Lots of lighter load cords get plugged into higher amp plugs/breakers.

[Jkwilson]

In this case, the 50 amp breaker would still trip - not a reason to worry.

Rob

I agree it’s not much of a worry, but a short may not be carrying the full 50A or could bypass the onboard breaker allowing users to draw up to 50A with equipment in the RV.

Cords are treated differently because the are largely visible. Cables and hidden wiring have much greater risk.

[howson]

Jkwilson -- Couldn't this be solved very easily? Have the park replace the 50A breaker in the pedestal with a 30A one. Should take all of 5 minutes, right?

[TNFSolitude]

Thanks all for the helpful info. I'll pass it on to my neighbor.