50 Amp RV Outlet vs. 50 Amp Welding Outlet

[sbosecker]

I'm specifying the electrical requirements of my upcoming build.

One of the three bays is designed to accommodate an RV. I don't have an RV but might store one for somebody in the future.

So I've been researching RV electrical requirements. I had assumed, prior to this research, that an RV could probably just use a NEMA 6-50R 50 amp Welding receptacle via an adapter of some sort. It turns out that will not work and, due to my research, I understand why. For 50 Amp service an RV needs a NEMA 14-50R receptacle.

So it looks to me that a welder - using a proper adapter such as a Hobart 770674 Adapter Cord - can use power from a NEMA 14-50R receptacle but an RV cannot use power from a NEMA 6-50R receptacle.

With that in mind, does anyone see a problem with specifying a 50 amp RV receptacle (NEMA 14-50R) and then using the appropriate adapter when I need to weld?

Scott

 

[CoopVA]

As long as the adapter is rated at the same voltage as the circuit, I see no problem with it.


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[The Cobbler]

RV is 120 volt, welder is 240 volt

 

[wyliesdiesels]

I'm specifying the electrical requirements of my upcoming build.

One of the three bays is designed to accommodate an RV. I don't have an RV but might store one for somebody in the future.

So I've been researching RV electrical requirements. I had assumed, prior to this research, that an RV could probably just use a NEMA 6-50R 50 amp Welding receptacle via an adapter of some sort. It turns out that will not work and, due to my research, I understand why. For 50 Amp service an RV needs a NEMA 14-50R receptacle.

So it looks to me that a welder - using a proper adapter such as a Hobart 770674 Adapter Cord - can use power from a NEMA 14-50R receptacle but an RV cannot use power from a NEMA 6-50R receptacle.

With that in mind, does anyone see a problem with specifying a 50 amp RV receptacle (NEMA 14-50R) and then using the appropriate adapter when I need to weld?

Scott

Do u know why? Its because a 6-50 has no neutral, a 14-50 does. A welder only needs 240v(and ground) 3-wire, whereas anRV needs 120v/240v which is 4-wire...

Look at nema config here:

http://en.m.wikipedia.org/wiki/NEMA_connector

So if u put in a 14-50R, then u could make or buy 14-50P to 6-50R adapter!

RV is 120 volt, welder is 240 volt

Not so black and white. While yes most if not all RVs are 120v, the bigger ones actually have a 120v/240v 4-wire plug, despite having all 120v devices/appliances. So technically, not ALL RVs are 120v...

 

[CoopVA]

RV is 120 volt, welder is 240 volt

Then no. You will need a separate dedicated circuit for both. If the RV was 240v, then you possibly could.


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[The Cobbler]

Then no. You will need a separate dedicated circuit for both. If the RV was 240v, then you possibly could.


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just to clarify...I was replying to OP

 

[W_A_Watson_II]

If your camper uses the NEMA 14-50 (240V-50A), then have the Garage wired to accommodate that. Then it's just a matter of purchasing or creating a pig-tale adapter to go from a NEMA 14-50 Plug to a NEMA 6-50 Receptacle.

 

[wyliesdiesels]

Here ya go, something like this:

http://www.amazon.com/dp/B003J8NMF0/?tag=atomicindus08-20

EDIT: whoops above one isnt available. Heres one on fleabay

http://m.ebay.com/itm/121509966207

Might be able to make a cheaper one yourself!

 

[sbosecker]

OK...

Maybe my understanding of the situation is incorrect but I don't think so.

Yes, an RV uses 120 volt service.

Yes, a welder uses 240 volt service.

The RV plug/receptacle (NEMA 14-50) uses 4 wires: Two 120 Volt “Hot” wires (normally red & black); A “Neutral” wire (normally white); A ”Ground” wire (normally bare copper).
This provides two 120 volt "supply lines" to the RV.

The Welder plug/receptacle (NEMA 6-50) uses 3 wires: Two 120 Volt “Hot” wires (normally red & black); A ”Ground” wire (normally bare copper).
This provides 240 volt service to the welder.

I think by looking at the above one can see that a welder - via an adapter - should be able to use the RV receptacle but not the other way around.

By using the Hobart adapter that I mentioned in my post, it is advertised to have the RV outlet provide 240 volt - 50 amp power to a welder and that makes perfect sense to me.

The RV outlet - with the proper adapter - would seem to allow the best of both worlds but I was wondering if I was missing something.

Best regards,

Scott

 

[sbosecker]

Here ya go, something like this:

http://www.amazon.com/dp/B003J8NMF0/?tag=atomicindus08-20

Yes sir.

I posted that link in my original post.

Best regards,

Scott

 

[sbosecker]

If your camper uses the NEMA 14-50 (240V-50A), then have the Garage wired to accommodate that. Then it's just a matter of purchasing or creating a pig-tale adapter to go from a NEMA 14-50 Plug to a NEMA 6-50 Receptacle.

Agreed.

Can you see any downside to this versus a dedicated circuit for both the RV and the welder?

My thinking is that the NEMA 14-50 with an adapter would be the most efficient way to wire this and have the ability to serve two masters.

Sometimes my thinking is wrong. Hence this post.

Best regards,

Scott

 

[CoopVA]

Well, that may work if the RV was 240v. Everything I've read from the OP says the RV is 120v. If that's the case, it won't work.

It's not a good idea to tap a 120v branch off of a 240v dedicated circuit. I'm pretty sure it would not be code compliant.



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[wyliesdiesels]

OK...

Maybe my understanding of the situation is incorrect but I don't think so.

Yes, an RV uses 120 volt service.

Yes, a welder uses 240 volt service.

The RV plug/receptacle (NEMA 14-50) uses 4 wires: Two 120 Volt “Hot” wires (normally red & black); A “Neutral” wire (normally white); A ”Ground” wire (normally bare copper).
This provides two 120 volt "supply lines" to the RV.

The Welder plug/receptacle (NEMA 6-50) uses 3 wires: Two 120 Volt “Hot” wires (normally red & black); A ”Ground” wire (normally bare copper).
This provides 240 volt service to the welder.

I think by looking at the above one can see that a welder - via an adapter - should be able to use the RV receptacle but not the other way around.

By using the Hobart adapter that I mentioned in my post, it is advertised to have the RV outlet provide 240 volt - 50 amp power to a welder and that makes perfect sense to me.

The RV outlet - with the proper adapter - would seem to allow the best of both worlds but I was wondering if I was missing something.

Best regards,

Scott

Yes thats true because the 6-50r is 3 pin. But backup. If a a x/3 NM-b cable or 4-wire feed was run to the j box of the 6-50r then the neutral is there and only a recepticle change is in order.

Yes sir.

I posted that link in my original post.

Best regards,

Scott

I didnt notice that earlier. Whoops.

I did find one on ebay! See my edit in #8...

Well, that may work if the RV was 240v. Everything I've read from the OP says the RV is 120v. If that's the case, it won't work.

It's not a good idea to tap a 120v branch off of a 240v dedicated circuit. I'm pretty sure it would not be code compliant.



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Who are u responding to?

And the OP did say 14-50 which is NOT just 120v...

 

[W_A_Watson_II]

I must be missing something. The OP never states the camper he might store is/needs 120V. He states that in his research "For 50 Amp service an RV needs a NEMA 14-50R receptacle". If he's going to install power for use by both a potential Camper and Welder, then he should install the NEMA 14-50P and use the adapter to connect his welder. If it turns out the camper only needs 120v then he should also be able to get by with the camper adapters, as it's not the ideal solution but should suffice to keep the camper batter charger and other storage appliances operational.

 

[sbosecker]

I must be missing something. The OP never states the camper he might store is/needs 120V. He states that in his research "For 50 Amp service an RV needs a NEMA 14-50R receptacle". If he's going to install power for use by both a potential Camper and Welder, then he should install the NEMA 14-50P and use the adapter to connect his welder. If it turns out the camper only needs 120v then he should also be able to get by with the camper adapters, as it's not the ideal solution but should suffice to keep the camper batter charger and other storage appliances operational.

W_A_Watson,

God bless you.

Best regards,

Scott

 

[CoopVA]

Yes thats true because the 6-50r is 3 pin. But backup. If a a x/3 NM-b cable or 4-wire feed was run to the j box of the 6-50r then the neutral is there and only a recepticle change is in order.



I didnt notice that earlier. Whoops.

I did find one on ebay! See my edit in #8...



Who are u responding to?

And the OP did say 14-50 which is NOT just 120v...

See post #9. He says the RV service is 120v.


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[CoopVA]

I must be missing something. The OP never states the camper he might store is/needs 120V. He states that in his research "For 50 Amp service an RV needs a NEMA 14-50R receptacle". If he's going to install power for use by both a potential Camper and Welder, then he should install the NEMA 14-50P and use the adapter to connect his welder. If it turns out the camper only needs 120v then he should also be able to get by with the camper adapters, as it's not the ideal solution but should suffice to keep the camper batter charger and other storage appliances operational.

See post #9.. He says the RV service is 120v...


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[wyliesdiesels]

See post #9. He says the RV service is 120v.


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He also said 14-50r. RVs ARE 120v because ALL the appliances are 120v only, however bigger RVs use a 120v/240v recepticle(14-50) so they can be fed more 120v power for things like dual or triple AC units.

The bottom line is the OP is asking about adapting a 14-50r to a 6-50r which IS possible and code legal!

Also, if all he needed was a 120v outlet for an RV, he could make an adapter that does 14-50r to 5-30r or TT-30R!

 

[CoopVA]

He also said 14-50r. RVs ARE 120v because ALL the appliances are 120v only, however bigger RVs use a 120v/240v recepticle(14-50) so they can be fed more 120v power for things like dual or triple AC units.

The bottom line is the OP is asking about adapting a 14-50r to a 6-50r which IS possible and code legal!

Ok, then that means he does have a 240v service to the RV and not a 120v service like he said. Right?


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[W_A_Watson_II]

Scott, you are welcome, and God Bless you as well. No down side, you just have a Neutral Wire in the outlet that the welder doesn't need/use. As the only leads going thru a breaker are the two hot leads, and as long as the Ground is properly sized, you will be all set.

Will

 

[wyliesdiesels]

Ok, then that means he does have a 240v service to the RV and not a 120v service like he said. Right?


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Correct but in the RV world it isnt considered 240v service. RVs are a weird breed. I use to have a trailer with a 14-50r but the label on the side said 120v shore power...go figure....yes it should be called 240v service but it isnt done...

 

[CoopVA]

Correct but in the RV world it isnt considered 240v service. RVs are a weird breed. I use to have a trailer with a 14-50r but the label on the side said 120v shore power...go figure....yes it should be called 240v service but it isnt done...

Ah! Well, no wonder I was confused... Thanks for straightening me out...

Learn something new every day. With that, I must then concur, and it will work with an adapter...


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[Tronyadorable]

Congratz on not owning a dual axle porta-potty.
Change out the receptacle.Tell whoever want you to store one to buy a barn( I know--he can't cause he pissed all his money away on gas, tolls and TV dinners).

 

[Milton Shaw]

The RV plugs I have seen have both the hots off the same buss bar on the panel, hence the 120 volt and 120 volt supply. Nothing in the RV is supposed to be 240 volt and they did not want 240 volt to the plug and to the RV that you would get from a L1, L2 way that you conventionally wire a 4 wire outlet. This was the custom on the 30 am RV plugs and continued to the 50 from what I saw at a neighbors RV wiring he had put in.

 

[CoopVA]

The RV plugs I have seen have both the hots off the same buss bar on the panel, hence the 120 volt and 120 volt supply. Nothing in the RV is supposed to be 240 volt and they did not want 240 volt to the plug and to the RV that you would get from a L1, L2 way that you conventionally wire a 4 wire outlet. This was the custom on the 30 am RV plugs and continued to the 50 from what I saw at a neighbors RV wiring he had put in.

Both hots off the same bus? Really? I don't think that's correct....


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[Norcal]

All the loads on a RV w/ a 50A plug are 120 volts, a 50A to 30A adapter just jumpers both hot legs in order run things, just can't run everything.

As said by others, just make a adapter.

 

[wyliesdiesels]

The RV plugs I have seen have both the hots off the same buss bar on the panel, hence the 120 volt and 120 volt supply. Nothing in the RV is supposed to be 240 volt and they did not want 240 volt to the plug and to the RV that you would get from a L1, L2 way that you conventionally wire a 4 wire outlet. This was the custom on the 30 am RV plugs and continued to the 50 from what I saw at a neighbors RV wiring he had put in.

Thats not right. So many things wrong with that. And just how would u hook up 2 wires to the same buss in a panel? With 2 separate breakers and no handle tie?

Maybe your friends wiring is like that but the RV recepticles Ive done and have seen have 240v at the recepticle...

And your talking 30a RV recepticle. Which would be a TT-30r. Which IS 120v...were talking 50a...

http://m.homedepot.com/p/Eaton-50-A...Temporary-RV-Power-Outlet-Box-CHU1S/100565603

Notice its rated 120v/240v...and its a 14-50r...

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

My BS meter is ******* on this one!!

 

[CoopVA]

All the loads on a RV w/ a 50A plug are 120 volts, a 50A to 30A adapter just jumpers both hot legs in order run things, just can't run everything.



As said by others, just make a adapter.

They still have to be on seperate bus if it's a 50 amp with two hots going into it. The 50 amp RV distribution panels I just googled have two hots feeding it. I'm pretty sure they are not on the same bus.


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[wyliesdiesels]

All the loads on a RV w/ a 50A plug are 120 volts, a 50A to 30A adapter just jumpers both hot legs in order run things, just can't run everything.

As said by others, just make a adapter.

What do mean by jumper? Combine?

 

[W_A_Watson_II]

An adapter to plug a 240V-50Amp camper into a 120V-30Amp receptacle does place both of the campers legs on the one load side, and yes you only have 30 Amps available for the total load.

An adapter to plug a 120V-30Amp camper into a 240V-50Amp receptacle doesn't jumper both legs together, it only uses one leg.

Most campers that run on 240V will try and split the load between the two legs, but some just run the 2nd AC only on the other leg.

 

[CoopVA]

I think we may be talking about a couple different things here.

From my tiny bit of research, it looks to me like it should go this way....

You need a 50amp 240v circuit to feed a welder. You also want to use this 50 amp 240 volt circuit to feed an RV distribution feed when you are not using the welder.

I think you may want to go ahead and set up your receptacle for the welder, then set up a cord with the same type of 50a plug you have for your welder on one end and a 50a outlet for the 50a RV to plug into on the other end. Then, you can plug in a 50a RV. If you have to plug in a 30a RV, then you get the adapter for a 50a to 30a...




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[W_A_Watson_II]

I think you may want to go ahead and set up your receptacle for the welder, then set up a cord with the same type of 50a plug you have for your welder on one end and a 50a outlet for the 50a RV to plug into on the other end. Then, you can plug in a 50a RV. If you have to plug in a 30a RV, then you get the adapter for a 50a to 30a...

Nope, you want it the other way. The NEMA 14-50P is a 4 wire, as it needs both hots, Neutral and Ground while the Welder is a 3-wire and don't use the neutral.

If he installed a 3 wire welder plug, the camper won't work as it needs the neutral.

Install the NEMA 14-50 and use an adapter for the welder.

 

[CoopVA]

Nope, you want it the other way. The NEMA 14-50P is a 4 wire, as it needs both hots, Neutral and Ground while the Welder is a 3-wire and don't use the neutral.

If he installed a 3 wire welder plug, the camper won't work as it needs the neutral.

Install the NEMA 14-50 and use an adapter for the welder.

Yep... That's right... I gotta stay off this thing when I'm on cold medicine...


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[wyliesdiesels]

wew. Glad we got things straightened out. Now that were done repeating, is there anything left unanswered??

 

[Norcal]

What do mean by jumper? Combine?

Yes, both L1, & L2 are combined, when the RV has 50A service there is 240V in the panel but loads are all 120 volts, when a 30A adapter is used only 120 volts is available in the panel.

 

[Syberia]

Don't most 240v welders come without cord/plug? Instead of messing with adapters, the OP could just put a 14-50p on the end of the welder and not hook up the neutral. It will work just fine.

 

[wyliesdiesels]

Thats another option!

 

[wyliesdiesels]

OP heres the stuff to make your own adapter...

http://www.amazon.com/gp/aw/d/B000PGVZ30/ref=mp_s_a_1_2?qid=1418623305&sr=8-2&pi=AC_SY200_QL40

http://www.amazon.com/gp/aw/d/B003X4338G/ref=mp_s_a_1_3?qid=1418623432&sr=8-3&pi=AC_SX200_QL40

http://m.homedepot.com/p/Southwire-6-3-SOOW-Black-600V-By-the-Foot-55809299/204632934/

Will cost ya just under $50 and take maybe an hour!

 

[Speedy Petey]

Wow! This thread is a prime example of why folks who don't know exactly what they're talking about should refrain from giving out advice. Two pages of assumptions and confusion.

Bottom line:
A 50A RV circuit is a 120/240V, 4-wire circuit. It's not "120", and it's NOT "240". It's 120/240V, using two hots, a neutral and a ground.

A welder is typically a straight 240V circuit. Two hots and a ground.

I'm specifying the electrical requirements of my upcoming build.

One of the three bays is designed to accommodate an RV. I don't have an RV but might store one for somebody in the future.

So I've been researching RV electrical requirements. I had assumed, prior to this research, that an RV could probably just use a NEMA 6-50R 50 amp Welding receptacle via an adapter of some sort. It turns out that will not work and, due to my research, I understand why. For 50 Amp service an RV needs a NEMA 14-50R receptacle.

So it looks to me that a welder - using a proper adapter such as a Hobart 770674 Adapter Cord - can use power from a NEMA 14-50R receptacle but an RV cannot use power from a NEMA 6-50R receptacle.

With that in mind, does anyone see a problem with specifying a 50 amp RV receptacle (NEMA 14-50R) and then using the appropriate adapter when I need to weld?

Scott

YES, you are correct. You can use your welder on your RV circuit using that exact adapter. You can also just replace the plug with a 14-50P plug and ignore the neutral prong.

 

[RickP]

Personally, I'd run 4 wires and swap out the 14-50r for a welding receptacle, then cap the neutral wire in the box. It's pretty easy to swap the receptacle if you ever decide to store an RV in there. I ran 4 wires to my 6-50r "just in case" and then I decided to install a subpanel a few years later.