NEC 314 Be Damned

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Natfuelbilll

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Came across a state job in progress where engineer (PE stamped drawings) specified 12"x12" pull boxes for 3" conduit straight pulled and 3" conduit angles pulls. The conductors installed are 4-350mcm with #1/0 equipment ground.

The cables look like twisted, barber shop sign and seem to be wringed out like an old rag.

I told the lead PE inspector that the cable should be removed and taken off the job and proper boxes installed. They'll probably just Megger test and use them. Thing is, the circuit provides power to a data center processing $100,000 per day. Crazy.

Pictures coming when I get back to the computer.

What are your thoughts?
 
It is interesting that wire size has nothing to do with box size. The box size minimum is either 6x or 8x the largest conduit. For 3" pipe you either 18" or 24" minimum depending on straight pull or angle pull and then other raceways will add to it.
 
Natfuelbilll said:
Skinny wire doesn't present a problem but this heavier stuff is totally suspect in my view.
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The sizing of the jbox is done by conduit size because that is what determines the largest conductors capable of being installed in it. The box you have is obviously too small even if #12 wires were installed in the 3" conduit
 
(couldn't edit previous post, posted on accident) Wires too big for conduit conduit too big for box I'd say the PE probably did load calculations multiple times and it kept going up and never got a chance to fully coordinate his drawings. If it's a data center there was probably no in depth permit or peer review so no one caught it

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Dennis Alwon said:
The box you have is obviously too small even if #12 wires were installed in the 3" conduit
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If they were pulled through and not spliced there is nothing wrong with what OP has NEC wise if the conductors were all 12 AWG. Not much difference then if a conduit body were used that likely isn't 6 or 8 times the raceway size in length.
 
Dennis Alwon said:
The sizing of the jbox is done by conduit size because that is what determines the largest conductors capable of being installed in it. The box you have is obviously too small even if #12 wires were installed in the 3" conduit
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This code section only applies to #4 and larger im pretty sure so you're incorrect. Smaller wires require a box fill Calc.

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Mea Cupa--- My post was meant to show that the conductors don't matter however they do need to be sized #4 or larger. The point is the wire size is not what determines the box size.
 
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