Plugging 20 amp a/c into 50 amp outlet

Jr70895 · Nov 12, 2023

Mobile home outdoor power supply is a pedestal that power to the mobile home plugs in much like an RV. The main power supply into the mobile home plugs into a 50 amp outlet to the breaker box inside the trailer.

The central a/c unit was an add on that was installed before I bought the trailer. It has a separate power supply cable that runs from the pedestal and wired directly into the a/c central unit. The cable also plugs into a 50 amp outlet on the pedestal.

The central unit went out and adding a 220 volt 20 amp window unit for now. Need to run 220 wire and install outlet below the window as currently don't have an outlet there.

Hired electrician who's ran 10/2 wire in conduit from the 50amp outdoor pedestal to a new 20amp breaker box attached to the side of the trailer. He will then pigtail inside to new wall outlet.

Several people have since told me that you can't use 10/2 wire and plug it into the 50 amp outdoor pedestal power supply to the breaker box then into the trailer. I'm not an electrician that's why I hired someone.

Was told it should be 6/2 wire from the outdoor pedestal to 20 amp breaker box then pigtail to indoor outlet with 10/2 wire. Right now the 10/2 wire and conduit has been installed but not connected to new breaker box etc. He will be back one day next week to complete.
I'm confused......
I did see online they sell a 50amp to 20amp adapter that could be used to convert 50 amp outlet to 20 amp a/c 220 volt plug.

James · Nov 12, 2023

@Megawatt is probably the best person to answer this,

Jr70895 · Nov 13, 2023

I guess no one can answer my question....Thanks

Megawatt · Nov 13, 2023

Jr70895 said:
I guess no one can answer my question....Thanks

Thank you for the picture.

Jr70895 said:
Mobile home outdoor power supply is a pedestal that power to the mobile home plugs in much like an RV. The main power supply into the mobile home plugs into a 50 amp outlet to the breaker box inside the trailer.

The central a/c unit was an add on that was installed before I bought the trailer. It has a separate power supply cable that runs from the pedestal and wired directly into the a/c central unit. The cable also plugs into a 50 amp outlet on the pedestal.

The central unit went out and adding a 220 volt 20 amp window unit for now. Need to run 220 wire and install outlet below the window as currently don't have an outlet there.

Hired electrician who's ran 10/2 wire in conduit from the 50amp outdoor pedestal to a new 20amp breaker box attached to the side of the trailer. He will then pigtail inside to new wall outlet.

Several people have since told me that you can't use 10/2 wire and plug it into the 50 amp outdoor pedestal power supply to the breaker box then into the trailer. I'm not an electrician that's why I hired someone.

Was told it should be 6/2 wire from the outdoor pedestal to 20 amp breaker box then pigtail to indoor outlet with 10/2 wire. Right now the 10/2 wire and conduit has been installed but not connected to new breaker box etc. He will be back one day next week to complete.
I'm confused......
I did see online they sell a 50amp to 20amp adapter that could be used to convert 50 amp outlet to 20 amp a/c 220 volt plug.

I really don’t see why it wouldn’t work since the electrician installed a sub panel and the AC is protected by a 20 or 30 amp breaker. According to the picture I’m going to assume that the middle receptacle is the one that’s going to be used. If it is used for any other loads then yes it should be #6 wire

Megawatt · Nov 13, 2023

James said:
@Megawatt is probably the best person to answer this,

@James the OP sent me a picture through the PM. Thank you for the heads up.

Jr70895 · Nov 14, 2023

Megawatt said:
Thank you for the picture.

I really don’t see why it wouldn’t work since the electrician installed a sub panel and the AC is protected by a 20 or 30 amp breaker. According to the picture I’m going to assume that the middle receptacle is the one that’s going to be used. If it is used for any other loads then yes it should be #6 wire

Yes, the center outlet will be used. This is all part of the original power supply that the trailer plugs into. You can see the main power cable from the pedestal that runs into the trailer that’s plugged in. The old cable is lying on the ground. Will use that outlet and run 10 gauge wires from the 50 amp outlet to the 20 amp breaker then pigtail into the trailer.
Several folks said you can’t do that. That you can’t use the 30 amp rated wire.
50 amp outlet, 30 amp wire being used, ran to a 20 amp outdoor breaker then pigtailed inside to the 20 amp outlet.
Was told wire must be 50 amps to the breaker box.
That’s why I’m so confused. If in fact it’s changed to 50 amp 6/3 wire from the outdoor existing pedestal to the new breaker box can it be wired to a 20 amp breaker box then pigtailed into the trailer?
I’m assuming the electrician has a handle on it and knows what he’s doing.

RetiredNY · Jan 5, 2024

Jr70895 said:
Yes, the center outlet will be used. This is all part of the original power supply that the trailer plugs into. You can see the main power cable from the pedestal that runs into the trailer that’s plugged in. The old cable is lying on the ground. Will use that outlet and run 10 gauge wires from the 50 amp outlet to the 20 amp breaker then pigtail into the trailer.
Several folks said you can’t do that. That you can’t use the 30 amp rated wire.
50 amp outlet, 30 amp wire being used, ran to a 20 amp outdoor breaker then pigtailed inside to the 20 amp outlet.
Was told wire must be 50 amps to the breaker box.
That’s why I’m so confused. If in fact it’s changed to 50 amp 6/3 wire from the outdoor existing pedestal to the new breaker box can it be wired to a 20 amp breaker box then pigtailed into the trailer?
I’m assuming the electrician has a handle on it and knows what he’s doing.

Will it work? Yes. Will the trailer burst into flames? No. But code allows a remote structure (trailer) to be powered with ONE circuit, which could be a 120 volt feeder (like to a detached garage from a house for a couple of lights, outlets, etc...) or a 240/120 volt multi-wire branch circuit like from a house (or pedestal) to a garage sub-panel for multiple 120v/ 240v circuits... but not TWO circuits. As the central a/c condenser previously fed from a separate pedestal circuit was located outside the structure I suppose most inspectors would allow it since the 2nd circuit does not enter the structure. But now you are entering the structure with a second feeder which technically, according to NEC is a violation.