Verifying required box volume for welding circuit

[vdotmatrix]

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

 

[Snoonyb]

And the ground?

 

[afjes_2016]

That receptacle is quite large and deep.
Although calculating the box fill you find it will meet code I would certainly suggest before installing the plastic box you try placing the receptacle in the box just as a quick reference to see how much room you will have for the conductors. The conductors are quite stiff and you may find it difficult to push the receptacle back into the box.

I would certainly entertain the thought of using a deep 4x4 metal box.