230V 30 amp receptacle

[vavet]

I had an electrician wire in a 230V 30 amp circuit for my lift when he was wiring the garage. I’ve changed my mind about where I want it thought. My 100 amp sub panel has plenty of space, so I’ve decided to run new 10/2 romex from the panel on a new breaker to the other side of the garage. Now I have an extra circuit that is simply terminated in a junction box with a blank cover plate.

What would be the best way to handle this? I plan to have the garage insulated and dry walled in the next year. I was thinking of adding a receptacle to this box so I could use it for whatever comes along- a bigger compressor, welder, etc.

Do these larger pieces of equipment typically require hardwiring inside the JB or can I install a plug? What type of plug? Twist lock or straight blade? The upside of using a plug and receptacle instead of hardwiring allows me some flexibility. What are the downsides of using a plug and receptacle?

 

[sberry]

Leave it till it's needed. Welders take 6-50.

 

[Crazyjake8493]

The upside of using a plug and receptacle instead of hardwiring allows me some flexibility.

Leaving it as it is for now gives you the most flexibility. Leave the blank cover on and if/when you find a piece of equipment to put there, then decide which outlet to use, or if you need to hardwire it.

 

[mike93lx]

Stationary equipment like a compressor need to be hardwired, but a welder would use a plug. Either way isn't a problem as you can do both feom the JB.

I agree, leave it unless it is in a really bad spot, like 15' up in the middle of the room.

 

[pattenp]

A welder will use a plug. A 30A circuit will limit you to about a 4HP compressor, 3HP and under can use plug, over 3HP should be hardwired.

 

[theoldwizard1]

Leave it till it's needed. Welders take 6-50.

True, but ... Few welders will ever come close to pulling the 50A that that plug is rated for. A 30A feed to a 6-50 is fine.

 

[sberry]

Correct especially new modern machines. It would serve most 50A machines too. There are only a couple exceptions to this and not super common to these type of garages.

 

[wyliesdiesels]

True, but ... Few welders will ever come close to pulling the 50A that that plug is rated for. A 30A feed to a 6-50 is fine.

Code does not permit a 50a outlet on a 30a circuit.

For a welder circuit, only the wire size can be reduced based on Table 630.11(A) but the breaker needs to be 50a if using a 6-50...

See table 210.21B(3)

EDIT: The above is wrong. I was commenting while drunk. Disregard. The correct application of the code for this is below in #10....

 

[sberry]

It does. We can't put a breaker larger than the outlet but no reason a guy can't do the reverse. The welder comes with instructions, says if the minimum wire is used it requires a smaller breaker, doesn't tell us to cut the end off and replace it.

 

[mm08822]

Code does not permit a 50a outlet on a 30a circuit.

For a welder circuit, only the wire size can be reduced based on Table 630.11(A) but the breaker needs to be 50a if using a 6-50...

See table 210.21B(3)

The first exception of 210.21B(3) permits otherwise.

For a welder ckt using reduced conductor sizing as permitted by 630.11(A), the cb for that ckt can only be 200% of welder FLC AND only 200% of the conductor ampacity. See NEC 630.12 A & B.

A welder with a 20A FLC and 30% duty cycle can be connected to a 6-50r using 14's with up to a 30A cb permitted.

A welder with a 20A FLC and 30% duty cycle can be connected to a 6-50r using 12's with up to a 40A cb permitted.

A welder with a 25A FLC and 30% duty cycle can be connected to a 6-50r using #10's with up to a 50A cb permitted.

 

[hichamaziz]

so thank you for thread

 

[pattenp]

Code does not permit a 50a outlet on a 30a circuit.

For a welder circuit, only the wire size can be reduced based on Table 630.11(A) but the breaker needs to be 50a if using a 6-50...

See table 210.21B(3)

You forgot the wording that table 210.21(B)(3) is used when there are two or more outlets on the circuit so if only one outlet for a welder it doesn't apply. Plus anyway there is an exception for welders as pointed out by mm08822.

 

[theoldwizard1]

Code does not permit a 50a outlet on a 30a circuit.

For a welder circuit, only the wire size can be reduced based on Table 630.11(A) but the breaker needs to be 50a if using a 6-50...

See table 210.21B(3)

Okay, explain that logic to me ! I can use #10 wire on a dedicated welding outlet (6-50) but I need a 50A breaker ?

While it is unlikely these days to find a welder that would pull 50A let alone one that would pull that much at a high duty cycle, why would NEC demand a 50A breaker with #10 wire ???

It does. We can't put a breaker larger than the outlet but no reason a guy can't do the reverse. The welder comes with instructions, says if the minimum wire is used it requires a smaller breaker, doesn't tell us to cut the end off and replace it.

That makes sense ! Undersizing a breaker, for the load or the wire, in inherently safer !

 

[sberry]

The 175-210 class migs actually require only 14. In fact the MVP come with a 14 cord, the 50A adapter is special and at 120 the circuit has ocpd , say 20A. The older or 240v only come with a 12 wire cord and 50A end for use on 50A welder circuits. They require and allow 14 but,,,, the breaker needs to be 30 for that wire.
Is that clear or do I need to work on it? A layman version could be, use wire 12 or better and it can use breaker 30 to 50.

 

[sberry]

My bud had a buzzer in garage with 8 wire in pipe to an outlet. No more spaces in the panel. He got 2 new machines. we jbox. Put 2 outlets on with a 12 and a 10. Put the new 211 on the 10and a 375 plas on the 12, could still plug the buzzer in if needed where the 211 is. This will run the 2 small machines,at once if it had to.

 

[wyliesdiesels]

You forgot the wording that table 210.21(B)(3) is used when there are two or more outlets on the circuit so if only one outlet for a welder it doesn't apply. Plus anyway there is an exception for welders as pointed out by mm08822.

yes yes i did. I knew specifically about that and forgot.

Thats what i get for commenting on here while drinking....

 

[sberry]

I get it worded wrong and am not drinking.

 

[2Big2Ride]

This thread is interesting and confusing. If I understand the previous posts correctly, a dedicated 240V circuit with a 30A breaker, 10/2 MC and a single 6-50r receptacle for use with a welder does not have the correct breaker because it doesn't match the receptacle. Did I get that correct?

Post #8
"Code does not permit a 50a outlet on a 30a circuit.

For a welder circuit, only the wire size can be reduced based on Table 630.11(A) but the breaker needs to be 50a if using a 6-50...

See table 210.21B(3)"

 

[pattenp]

This thread is interesting and confusing. If I understand the previous posts correctly, a dedicated 240V circuit with a 30A breaker, 10/2 MC and a single 6-50r receptacle for use with a welder does not have the correct breaker because it doesn't match the receptacle. Did I get that correct?

Not correct.

 

[wyliesdiesels]

This thread is interesting and confusing. If I understand the previous posts correctly, a dedicated 240V circuit with a 30A breaker, 10/2 MC and a single 6-50r receptacle for use with a welder does not have the correct breaker because it doesn't match the receptacle. Did I get that correct?

Post #8
"Code does not permit a 50a outlet on a 30a circuit.

For a welder circuit, only the wire size can be reduced based on Table 630.11(A) but the breaker needs to be 50a if using a 6-50...

See table 210.21B(3)"

Disregard my comment.

I was drunk and not paying attention.