DIY Home Improvement Forum banner
1 - 17 of 17 Posts

· Registered
Joined
·
105 Posts
Discussion Starter · #1 ·
I am installing a 240v 40a welding circuit using 8-2 8awg romex and respectfully ask someone to please verify my box requirement below.

The circuit will terminate in a plastic 18cu in box with a 50a/250v outlet.

I calculate a volume of 15cu in. box requirement and is within this plastic box limit.

Thanks in advance.

Alphatig 201xd welder
 

· Electrician
Joined
·
412 Posts
Are you the same individual from another site asking about the receptacles?

15 cubic inches should be accurate.

I would use a 2 gang box, install the welder receptacle, and a cover plate that would cover it.

If you're using something like this the instructions will state it needs a 2 gang box or similar, and not to be installed in a single gang box.


Sent from my new phone. Autocorrect may have changed stuff.
 

· Registered
Joined
·
3,257 Posts
I have put in several hundred of those same receptacles. I recommend using a deep 4² box since if you cut the #8's to provide the correct length per code, all that mass is hard to get in a standard depth box. The receptacle also requires quite a bit of force to pull it up properly so a plastic box is asking for failure.

The industry standard nomenclature for the box 4-SDW-FB-SPL which gets you a 4" square box that is 2 1/8" deep and has a side mounting bracket and both 1/2 and 3/4 knock outs. It has 30.3 in³ and the mud ring or surface mount ring (whichever you decide to use) will add a bit more. If you use anything smaller, you're just intentionally making it hard on yourself. A small box also puts a lot of stress on the receptacle terminals when you cram it into the box and those receptacles can be damaged that way.
 

· Registered
Joined
·
105 Posts
Discussion Starter · #4 · (Edited)
Are you the same individual from another site asking about the receptacles?

15 cubic inches should be accurate.

I would use a 2 gang box, install the welder receptacle, and a cover plate that would cover it.

If you're using something like the instructions will state it needs a 2 gang box or similar, and not to be installed in a single gang box.


Sent from my new phone. Autocorrect may have changed stuff.
Yes, i am one in the same and asked the moderator to delete that account and registered here.

So yes, that is the exact outlet.

There is another black self contained outlet that i cannot upload an image of here for some reason. The reason i chose this one and the need to get the right box for it, is i am also running electrical pvc down the wall to it and that fixture only has one way conduit will attach to it except from behind.

The welder’s cord points down and the cable would point up and by putting the other in a 2-gang box, i can rotate it 180 degrees to accommodate the power cord how i want it so it would hang down properly. Hard to describe.

I Did read somewhere that this outlet needed a 2-gang box. Now that i think of it, I should have a larger box because of the 8awg monster wire and the need to have perhaps 6-10” extra wire in the box to work with in the future. I bought both sized boxes while at Lowes, the 2-gang similar to this:

CARLON-2-Gang-Gray-PVC-Weatherproof-New-Work-Old-Work-Standard-Square-Exterior-Electrical-Box

(It wont let me post a link or images)

I pulled permit for this job but just want to pass the first time. Thanks for your help man!
 

· Registered
Joined
·
105 Posts
Discussion Starter · #5 ·
I have put in several hundred of those same receptacles. I recommend using a deep 4² box since if you cut the #8's to provide the correct length per code, all that mass is hard to get in a standard depth box. The receptacle also requires quite a bit of force to pull it up properly so a plastic box is asking for failure.

The industry standard nomenclature for the box 4-SDW-FB-SPL which gets you a 4" square box that is 2 1/8" deep and has a side mounting bracket and both 1/2 and 3/4 knock outs. It has 30.3 in³ and the mud ring or surface mount ring (whichever you decide to use) will add a bit more. If you use anything smaller, you're just intentionally making it hard on yourself. A small box also puts a lot of stress on the receptacle terminals when you cram it into the box and those receptacles can be damaged that way.
I wanted to avoid a metal box because i will have to pigtail a ground to it. Thank you for responding. Btw, how extra wire should i have in there? I fergit how much extra but there should be some .
 

· Registered
Joined
·
3,257 Posts
Code is 6" minimum but many electricians will tell you 8" makes dressing the wires easier. I always used my hand fully spanned out for measuring it.
 

· Electrician
Joined
·
412 Posts
I would use a metal box as suggested by surferdude2.

You wouldn't have to pigtail it to the box per say, just land the ground wire under the screw provided in the box before connecting it to the receptacle.

Iberville and other manufacturers make a "shoebox" cover for a 4x4 box. I believe the cover is iberville part #BC8366. I'll have to confirm this.

The 8/2 NMD cable I buy has a solid ground wire. This makes landing the ground wire one metal box easy. (I'm in canada, and our boxes, even the plastic ones, have a ground screw we need to connect to. Fun fact).

Tomorrow I can get a photo of how clean the install would look this way.

Sent from my new phone. Autocorrect may have changed stuff.
 

· Registered
Joined
·
105 Posts
Discussion Starter · #8 · (Edited)
https://www.lowes.com/pd/CARLON-2-G...e-Interior-Exterior-Electrical-Box/1000975776

Whadaya know it let me post a link.

https://www.lowes.com/pd/Utilitech-Black-50-Amp-Round-Industrial-Outlet/4013829

So here is the ready to go outlet...

wellllllll, I am in a hotel room in Portsmouth heading home in the morning and I just noticed that the plug on my welder from this picture will actually fit the black ready outlet if it were mounted on the wall upside down and the conduit going in to it from it’s bottom!

This changes everything.
 

Attachments

· Electrician
Joined
·
412 Posts
Here are some images of a 6-50/welder plug installed in a 4x4x2 1/8" box with a "shoebox" cover.

I would do this long before using an all-in-one plug cover box all in one.

The all-in-one would work too as long as the cord is actually as pictured.

Sent from my new phone. Autocorrect may have changed stuff.
 

· Registered
Joined
·
105 Posts
Discussion Starter · #10 ·
Very nice!
Here are some images of a 6-50/welder plug installed in a 4x4x2 1/8" box with a "shoebox" cover.

I would do this long before using an all-in-one plug cover box all in one.

The all-in-one would work too as long as the cord is actually as pictured.

Sent from my new phone. Autocorrect may have changed stuff.
 

· Registered
Joined
·
105 Posts
Discussion Starter · #12 ·
Mine is a 39 foot run into my shop across the ceiling in some grey electrical pvc, down the adjacent wall to the proposed outlet. I want to keep metal off this block wall because of humidity that comes through masonry, and why i used the pvc boxes. Your work is nice looking.
 

· Electrician
Joined
·
412 Posts
Mine is a 39 foot run into my shop across the ceiling in some grey electrical pvc, down the adjacent wall to the proposed outlet. I want to keep metal off this block wall because of humidity that comes through masonry, and why i used the pvc boxes. Your work is nice looking.
Well if you want to keep metal off the block wall, I would avoid the all-in-one receptacle. The back side is metal. Alternatively you can mount a piece of either treated wood or cedar against the block first.

A PVC box will work fine, it's just not my first choice.

And thank you, I like to make things look good. I know that the red cable needs a strap...

Sent from my new phone. Autocorrect may have changed stuff.
 

· Electrician
Joined
·
412 Posts

· Ret. Elec. Contractor
Joined
·
798 Posts
I am installing a 240v 40a welding circuit using 8-2 8awg romex and respectfully ask someone to please verify my box requirement below.
I calculate a volume of 15 cu in. box requirement

#8 has a volume requirement of 3.0 cu in.
2X3.0 =6
Receptacle takes twice the wire volume
2X3.0 =6
The #10 ground has a volume requirement of 2.5 cu in.
6+6+2.5=14.5 cu in.
 

· Registered
Joined
·
105 Posts
Discussion Starter · #16 ·
This is exactly what i planned to do.i will use a piece of wood to keep it off the block. Last night i couldnt find the one pipe box to as an example, and used the two box. That #8 cable is going to suck to work with. I would complain alot using the #12.
Well if you want to keep metal off the block wall, I would avoid the all-in-one receptacle. The back side is metal. Alternatively you can mount a piece of either treated wood or cedar against the block first.

A PVC box will work fine, it's just not my first choice.

And thank you, I like to make things look good. I know that the red cable needs a strap...

Sent from my new phone. Autocorrect may have changed stuff.
 

· Electrician
Joined
·
412 Posts
This is exactly what i planned to do.i will use a piece of wood to keep it off the block. Last night i couldnt find the one pipe box to as an example, and used the two box. That #8 cable is going to suck to work with. I would complain alot using the #12.
#8 is definitely not that bad to work with... especially if you use the all-in-one plug. With those, you cut them to the right length, strip them, and the terminals actually open up to lay the wires into the lugs (unless they changed the design).

250mcm is much worse to work with.

Sent from my new phone. Autocorrect may have changed stuff.
 
1 - 17 of 17 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top