Wiring a 50A Outlet

[SpdSurfn]

I'm looking at installing a 50A outlet at home and would like confirmation/feedback as to whether or not the following links are the right direction I need to follow.

http://www.myrv.us/electric/Pg/50amp_Service.htm

http://www.myrv.us/Imgs/PDF/50-amp%20Service.pdf

http://www.myrv.us/electric/index.htm

[Calbar]

If you are not sure about what you are doing I would have an electrician wire it for you. May be a lot cheaper than missing something and damaging the trailer, house or a fire. JMHO.

Rob

[Chiefblueman]

I'm looking at installing a 50A outlet at home and would like confirmation/feedback as to whether or not the following links are the right direction I need to follow.

http://www.myrv.us/electric/Pg/50amp_Service.htm

http://www.myrv.us/Imgs/PDF/50-amp%20Service.pdf

http://www.myrv.us/electric/index.htm

If you are using NM-B cable to wire this circuit you need to use #6/3 with ground. A couple of your links refer to using #8 if under 25ft. This is only good for 40 amps in NM-B configuration.

[RVRunners]

NEMA 14-50R is the correct receptacle to purchase. #6-3 copper wire with a 50 Amp double pole breaker. The wiring diagrams shown in the attachments you posted are correct. As someone else suggested before if you are uncertain about what you are doing you should hire an electrician to complete the work. This may be a good opportunity to invest in a power management/surge protector. I never plug our fifth wheel in without one. I have the 50 amp SurgeGuard portable unit by Southwire. When I first installed our home 50amp receptacle I knew that if I had something screwed up the SurgeGuard unit would catch it and prevent a power issue causing problems with the RV electrical system. Good luck!

[RobM]

I'm trying to have a 50A at the house also. I have read about the errors even electricians make by treating the 50A RV receptacle like a 240V dryer receptacle. I just got off the phone with an electrician that told me that the 50A is 240V and is separated at the breaker box IN the trailer to two 120V legs. He is incorrect, no? I told him I'd let him know.....
I have found this "somewhere" on the internet...
• Do not confuse the 14-50R with the 240-volt household outlet familiar from its use in powering clothes dryers and cookers. They are “common” outlets, meaning the two 120-volt supplies work together to deliver 240 volts to a 240-volt appliance. The 14-50R is an “uncommon” outlet, meaning it delivers two 120 volts currents. Your RV must be thought of as one very large 120-volt appliance. Even certified electricians who are unfamiliar with RVs can mistakenly assume an enormous RV is a 240-volt appliance, but plugging it into a 240-volt supply will destroy all appliances and accessories, and can cause fire. A wrongly-wired 50-amp service can introduce 240 volt electricity to your RV with the same results.

[Jerryr]

I'm trying to have a 50A at the house also. I have read about the errors even electricians make by treating the 50A RV receptacle like a 240V dryer receptacle. I just got off the phone with an electrician that told me that the 50A is 240V and is separated at the breaker box IN the trailer to two 120V legs. He is incorrect, no? I told him I'd let him know.....
I have found this "somewhere" on the internet...
• Do not confuse the 14-50R with the 240-volt household outlet familiar from its use in powering clothes dryers and cookers. They are “common” outlets, meaning the two 120-volt supplies work together to deliver 240 volts to a 240-volt appliance. The 14-50R is an “uncommon” outlet, meaning it delivers two 120 volts currents. Your RV must be thought of as one very large 120-volt appliance. Even certified electricians who are unfamiliar with RVs can mistakenly assume an enormous RV is a 240-volt appliance, but plugging it into a 240-volt supply will destroy all appliances and accessories, and can cause fire. A wrongly-wired 50-amp service can introduce 240 volt electricity to your RV with the same results.

Your electrician is correct. There is nothing in the RV that uses 240 volts. The 240 volts are separated in the RV breaker box to feed 2-120 volt legs.

Your home breaker box does the same. The home main breaker is a double pole 240 volt breaker that feeds 2-120 volt legs. Appliances at home that require 240 volts utilize a double breaker to feed the 2 out if phase 120v legs to the 240 volt appliance like a range, AC or water heater.

A14-50R receptacle is not unusual. Many oven ranges use that receptacle.

Older dryers were 3 wire receptacles, which didn’t have a neutral. 50 amp RVs REQUIRE a Neutral. Newer homes use a 4-wire dryer receptacle.

[Jerryr]

If you are using NM-B cable to wire this circuit you need to use #6/3 with ground. A couple of your links refer to using #8 if under 25ft. This is only good for 40 amps in NM-B configuration.

Correct for NM-B, UF etc Romex. . If you run separate stranded THHN or THWN in a raceway (PVC conduit, EMT or Non Metallic Conduit) you can run 8AWG up to about 100 ft by code. 4 each #8 THWN wires easily fits into 3/4 inch PVC conduit.
https://www.cerrowire.com/products/r...pacity-charts/

[boyscout]

@Chiefblueman / @RVRunners I was surprised to read on the site linked by @SpdSurfn above that a Progressive EMS would not necessarily protect against an open Neutral situation.

The "Open Neutral" article at the index link below reports that someone's appliances were destroyed because the park's pedestal had a weak neutral connection, resulting in 200+ volts appearing on one of the 120V legs in the trailer. In the Q&A the author asserts that the EMS won't respond fast enough to this condition to prevent damage and says that load-testing the pedestal every time we hook up is required.

Do you guys have an opinion on that?

[LV Naturist]

Your electrician is correct. There is nothing in the RV that uses 240 volts. The 240 volts are separated in the RV breaker box to feed 2-120 volt legs.

Your home breaker box does the same. The home main breaker is a double pole 240 volt breaker that feeds 2-120 volt legs. Appliances at home that require 240 volts utilize a double breaker to feed the 2 out if phase 120v legs to the 240 volt appliance like a range, AC or water heater.

A14-50R receptacle is not unusual. Many oven ranges use that receptacle.

Older dryers were 3 wire receptacles, which didn’t have a neutral. 50 amp RVs REQUIRE a Neutral. Newer homes use a 4-wire dryer receptacle.

Jerry, I don't claim to be an electrician, but i do have a working knowledge. Maybe I'm misunderstanding your response but I interpreted RobM's electrician telling him that the 50 A to the RV is 240 volts (L1, L2, G (no neutral)) and the rv breaker box separates that into 2 120V legs (L1, L2, N, G). "50A is 240V and is separated at the breaker box IN the trailer to two 120V legs". If that's what he is saying, wouldn't that be incorrect? Unless I mis-read, his electrician is wanting to wire the plug at the house like an old dryer...

John

[Jerryr]

Jerry, I don't claim to be an electrician, but i do have a working knowledge. Maybe I'm misunderstanding your response but I interpreted RobM's electrician telling him that the 50 A to the RV is 240 volts (L1, L2, G (no neutral)) and the rv breaker box separates that into 2 120V legs (L1, L2, N, G). "50A is 240V and is separated at the breaker box IN the trailer to two 120V legs". If that's what he is saying, wouldn't that be incorrect? Unless I mis-read, his electrician is wanting to wire the plug at the house like an old dryer...

John

If the electrician was considering wiring as an old 3-wire dryer he is incorrect. A 3 wire dryer does not have a neutral which is required to provide 120 volts.

I am not an electrician but in my previous employment we sold equipment that required a 50 amp 14-50R receptacle. We would provide the receptacle to the customer and their electrician would wire it. I’ve checked 100’s of 14-50R receptacles for proper wiring. About 10% of the time professional electricians had wired them incorrectly.

This is the correct wiring of a 14-50R