My father in law recently wired in a 50amp rv hookup in our garage. He used a double pole 50amp breaker and ran new 10/2 wire from breaker box to 50amp receptacle approximately 20ft. From my research a 220 3 wire hookup is not code. What problems or hazards could arise wired like this instead of the correct way with a 4 wire setup. From my understanding the camper gets 220 and converter knocks it down to 110 where it’s needed. We have 2 a/c units, fridge, washer/dryer....thanks in advance!
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Wiring rv hookups From garage
- Thread starter cstrode55
- Start date
My father in law recently wired in a 50amp rv hookup in our garage. He used a double pole 50amp breaker and ran new 10/2 wire from breaker box to 50amp receptacle approximately 20ft. From my research a 220 3 wire hookup is not code. What problems or hazards could arise wired like this instead of the correct way with a 4 wire setup. From my understanding the camper gets 220 and converter knocks it down to 110 where it’s needed. We have 2 a/c units, fridge, washer/dryer....thanks in advance!
RV 50A outlets are 120/240 volts, nothing uses 240 volts, all loads are 120 volts, the receptacle is a 4-wire device, requiring a neutral, grounding conductor, and 2 hot legs, 10 AWG is 30 ampere wire, not 50A, 10/2 is good for a 30A 120V RV receptacle but does not work for a 50A RV circuit, needs 6/3 NM cable or 8 AWG, THHN/THWN if in conduit.
110V & 220V are obsolete voltages.
larry4406
Well-known member
RV 50A outlets are 120/240 volts, nothing uses 240 volts, all loads are 120 volts, the receptacle is a 4-wire device, requiring a neutral, grounding conductor, and 2 hot legs, 10 AWG is 30 ampere wire, not 50A, 10/2 is good for a 30A 120V RV receptacle but does not work for a 50A RV circuit, needs 6/3 NM cable or 8 AWG, THHN/THWN if in conduit.
110V & 220V are obsolete voltages.
Very timely thread. Our customer wants a 50A RV outlet put in his garage. I just started researching this. I have requested he provide the specifications for his hookup.
Looks like the 50A RV outlet for this is NEMA14-50R and uses 4-wire feed. I think these are normally fed with 6/3 and connected to a 50A double pole breaker.
https://www.garagejournal.com/forum/showthread.php?t=272579
Looks like some RVS and travel trailers also use a TT-30 which is 30A 120V. I think these are normally fed with 10/2 and connected to a 30A single pole breaker.
This is all I have learned so far and hopefully I have not been misinformed.
I am sure our resident sparkies will chime in!
AntonLargiader
Well-known member
If he used the right kind of receptacle (14-50) then how did he connect it with 3-wire? Jumpered the ground to the neutral?
Basically any 5th wheel RV, and some large TTs are going to have a NEMA 14-50 plug and require a 50A 4 wire outlet. They do not have any 240V usage, they simply have 2 sides of the distribution panel, one for each 120V leg.
Most TTs are going to have a 30A, 120V plug.
Virtually everything in the OP is wrong. 10AWG is not rated for a 50A connection, and should be upgraded to 6AWG.
Second, you need a 3 wire plus ground, so NM-b 6/3 for the correct plug.
If the 10/2 is wired to a 4 wire 50A outlet with a 50A breaker, that is a major hazard and needs to be fixed ASAP. The likelyhood of an RV drawing 50A on either leg is pretty low, but could still potentially happen, and cause a fire.
The other hazard is with the current installation, the ground is now acting as a neutral, which again is dangerous.
Most TTs are going to have a 30A, 120V plug.
Virtually everything in the OP is wrong. 10AWG is not rated for a 50A connection, and should be upgraded to 6AWG.
Second, you need a 3 wire plus ground, so NM-b 6/3 for the correct plug.
If the 10/2 is wired to a 4 wire 50A outlet with a 50A breaker, that is a major hazard and needs to be fixed ASAP. The likelyhood of an RV drawing 50A on either leg is pretty low, but could still potentially happen, and cause a fire.
The other hazard is with the current installation, the ground is now acting as a neutral, which again is dangerous.
I believe that is only per the 2020 code, so in most states it wouldn't be required yet.In addition to the lack of a neutral and wrong wire size, I believe the breaker needs to be a GFCI.
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In addition to the lack of a neutral and wrong wire size, I believe the breaker needs to be a GFCI.
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Not unless they are in Massachusetts, or if any other State has adopted the 2020 NEC.
Not unless they are in Massachusetts, or if any other State has adopted the 2020 NEC.
Even as far back as 1996 (my oldest code book) article 210.8 requires all non dwelling unit 15 and 20 amp outlets to be GFCI protected. The RV I ran power for last summer did not have GFCI outlets or breakers so I put the outlet on a GFCI breaker which protects all circuits down stream.
My take is that is the requirement unless the local AHJ says orhetwise
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Even as far back as 1996 (my oldest code book) article 210.8 requires all non dwelling unit 15 and 20 amp outlets to be GFCI protected. The RV I ran power for last summer did not have GFCI outlets or breakers so I put the outlet on a GFCI breaker which protects all circuits down stream.
My take is that is the requirement unless the local AHJ says orhetwise
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We are not discussing 15 & 20A receptacles, the 30&50A RV receptacles are the topic. They only require GFCI protection under the 2020 code.
I looked at article 551.4. C which requires GFCI for RVs but wants it at the RV. The RV Installed an outlet for did not have any GFCI protection so I put it on a GFCI breaker.
I have not seen the 2020 code
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I have not seen the 2020 code
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Terry D
Well-known member
We are not discussing 15 & 20A receptacles, the 30&50A RV receptacles are the topic. They only require GFCI protection under the 2020 code.
I believe he might be referring to the receptacles inside the RV. The bathrooms, kitchens and outside receptacles need to be GFCI protected. This doesn't mean that the 50 amp receptacle feeding the RV has to be GFCI protected, until the 2020 code is adopted in his area, but I guess its one way of doing it
zmotorsports
ALLIANCE MEMBER
My father in law recently wired in a 50amp rv hookup in our garage. He used a double pole 50amp breaker and ran new 10/2 wire from breaker box to 50amp receptacle approximately 20ft. From my research a 220 3 wire hookup is not code. What problems or hazards could arise wired like this instead of the correct way with a 4 wire setup. From my understanding the camper gets 220 and converter knocks it down to 110 where it’s needed. We have 2 a/c units, fridge, washer/dryer....thanks in advance!
It should be wired in like any 120/240 volt dryer in your home. You will need two 110-volt legs. They are not running 240VAC and stepped down, just two 110-volt legs. Keep in mind however, that if he's running one of the larger RV's with modern amenities he will possible have a 240volt dryer much like in your home so will need the amperage if doing more than convenience charging or needing a "buddy plug" wired in.
nadogail
Well-known member
IMHO, Poor judgement on the original installers part
dcg9381
Well-known member
I have no idea. Everything aeems to work in the camper.
Lighting is 12V, fridge function is 12V. I'm surprised it works with a 240V 3-wire hookup (no neutral). I wouldn't expect AC or microwave to work.
dcg9381
Well-known member
Very timely thread. Our customer wants a 50A RV outlet put in his garage. I just started researching this. I have requested he provide the specifications for his hookup.
Looks like the 50A RV outlet for this is NEMA14-50R and uses 4-wire feed. I think these are normally fed with 6/3 and connected to a 50A double pole breaker.
https://www.garagejournal.com/forum/showthread.php?t=272579
Looks like some RVS and travel trailers also use a TT-30 which is 30A 120V. I think these are normally fed with 10/2 and connected to a 30A single pole breaker.
This is all I have learned so far and hopefully I have not been misinformed.
I am sure our resident sparkies will chime in!
This is correct.
Look at installing an Siemens Talon sub-panel (about $150) - has two connections for RV (50A / 30A) and a 20A GFCI... Includes the breakers. Your customer will love you.
AntonLargiader
Well-known member
Lighting is 12V, fridge function is 12V. I'm surprised it works with a 240V 3-wire hookup (no neutral). I wouldn't expect AC or microwave to work.
The 240V recep could be wired so that ground is jumpered to neutral. A few pics would be great but the O.P. knows it needs to be fixed regardless.
wyliesdiesels
Well-known member
Wow what a mess
Should make the original installer come back and fix it
Should make the original installer come back and fix it
sberry
Banned
I say not,,, fix himself.
sberry
Banned
Lighting is 12V, fridge function is 12V. I'm surprised it works with a 240V 3-wire hookup (no neutral). I wouldn't expect AC or microwave to work.
It would work.
teamextreme
Well-known member
Wow what a mess
Should make the original installer come back and fix it
Original installer was his father in law. That could make for an awkward Thanksgiving dinner.
sberry
Banned
Guy doesn't understand it the first time,,, not much he gonna the second.
I ran wire to a garage a while back and the woman had a bud come hook it up. The fitting wasn't bad but he made the comment that he didn't know why I used 4 wires and he only hooked 3,,, ha
I ran wire to a garage a while back and the woman had a bud come hook it up. The fitting wasn't bad but he made the comment that he didn't know why I used 4 wires and he only hooked 3,,, ha
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wyliesdiesels
Well-known member
Original installer was his father in law. That could make for an awkward Thanksgiving dinner.
well thats even worse. Father in law want his daughter to die in a fire?
38Chevy454
Well-known member
The 50 amp 14-50 RV plug as Zmotorsports said has 2 legs of 120v at 50 amps each. 120v x 50A x 2 legs = 12000 watts available power. The 2 hot legs are 240v between them. But since the RV uses 120v, it has a neutral required for each leg. It is true some high end motorhome use 240v, but typical RV does not and the systems are independent 120vac, or 12vdc in case of lighting or some control pieces like slide motors. So it has 4 wires needed for it to work, unless the ground is connected to neutral and the ground us acting as the neutral. With no corresponding ground safety. 4 wires: 2 hot legs 180 degrees out of phase, 1 neutral, and 1 ground.
A 30 amp RV plug has 1 leg of 120v at 30 amps. 120v x 30A x 1 leg = 3600 watts available. Has 3 wires: 1 hot leg, 1 neutral, and 1 ground.
An adapter to run a 50A RV on a 30A circuit splits the power (3600 watts) between all uses in the RV. The adapter won't work for the high end motorhome that needs the 240v.
I suggest the OP have the circuit rewired to a 30A 120v RV type plug.
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A 30 amp RV plug has 1 leg of 120v at 30 amps. 120v x 30A x 1 leg = 3600 watts available. Has 3 wires: 1 hot leg, 1 neutral, and 1 ground.
An adapter to run a 50A RV on a 30A circuit splits the power (3600 watts) between all uses in the RV. The adapter won't work for the high end motorhome that needs the 240v.
I suggest the OP have the circuit rewired to a 30A 120v RV type plug.
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MikeinNorthWales
Well-known member
Let's step back just a bit and ask a few questions. It is in your garage- is the RV kept in the garage? Is this used just to keep the batteries charged and power the fridge? Will you run AC? Do you plan to stay in the RV while at home?
If you want to charge the battery and run the fridge before a trip, adapters down to 15A will work just fine. If you want AC, 30A will run one unit, and you can use the wires already in place with the correct outlet, wired correctly. The only cost will be a 50A-30A adapter.
If you are going to "live" in it and use every appliance, you need to rewire it correctly.
30A and 50A RV outlets have a wiring standard. If they didn't, you couldn't just plug in at any campground across the country. If 240VAC is used in a coach for an appliance, that is achieved downstream from the outlet and cord. It has nothing to do with the outlet, other that it must be a 50A (2 leg), not a 30A (1 leg).
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If you want to charge the battery and run the fridge before a trip, adapters down to 15A will work just fine. If you want AC, 30A will run one unit, and you can use the wires already in place with the correct outlet, wired correctly. The only cost will be a 50A-30A adapter.
If you are going to "live" in it and use every appliance, you need to rewire it correctly.
30A and 50A RV outlets have a wiring standard. If they didn't, you couldn't just plug in at any campground across the country. If 240VAC is used in a coach for an appliance, that is achieved downstream from the outlet and cord. It has nothing to do with the outlet, other that it must be a 50A (2 leg), not a 30A (1 leg).
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nadogail
Well-known member
Who is going to be responsible when the obviously improper wiring causes a fire?