[mm1602]

I am completing some 347V wiring and I am being asked to use 4"x4" boxes (junction, pull, and device) which are stamped with 347v. These are available but other that having four less knockouts on the side there is nothing different. The steel gauge appears to be the same. There appears to be no differences to justify using them and I can not find anything in the code mandating this. Please clarify if possible. Thank you


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[Speedy Petey]

If you can't find it in the code book then it's not required.
What did the inspector say? Did he cite a reference? If not ask for one.
Where are you located?

 

[darren79]

I assume you are doing lights if you are working with 347V. We always use regular 4x4. 6x6 etc with no special markings. Device boxes for light switches need to be a special 347V box since the switch is a different size.

 

[Vintage Sounds]

You can't have side knockouts on a box used for a switch on a 347v circuit. For a regular JB that doesn't apply.

 

[mm1602]

You can't have side knockouts on a box used for a switch on a 347v circuit. For a regular JB that doesn't apply.

Where does it state in the code book that it needs to be a special 347V box for switches. I am located in Canada and I understand that the box needs to be compatible for the 347V switch but in a 4x4 situation just the cover needs to be compatible, not necessarily the box

 

[309a]

I recently installed a 600v 30a 3 wire Hubble twist lock. The screws align with a standard 1110 box. a 347 style 1110 box wouldn't align.

 

[LGLS]

Don't they make stamped 347V covers? Or stickers?

 

[Big John]

Help a non-Canadian out. What's the logic behind having different boxes for different voltages?

 

[KDC]

Less about the boxes and more about the switch in 347V circuits. They require a different strap length so they're not readily interchangeable with standard switches.

I guess it comes down to the "readily interchangeable" part of 14-512. If they consider the cover to be a readily interchangeable part, I can see where they're coming from.

 

[Aegis]

Also you'll need a divider between 2gang (and up) boxes for 347v switches even if it's the same cct.

14-514

 

[Vintage Sounds]

Where does it state in the code book that it needs to be a special 347V box for switches. I am located in Canada and I understand that the box needs to be compatible for the 347V switch but in a 4x4 situation just the cover needs to be compatible, not necessarily the box

I'm on my phone and not near my CEC but I think it's either in section 14 or 30. The rule does say that any box used for a 347v switch can't have knockouts on the side though. In this case if you wanted to put your switch in a 4x4 box, regardless of which coverplate you use it won't be legal to use a regular one because it has knockouts on all sides. 347v utility boxes also come with only top and bottom knockouts.