Why N7 junction box

[Howard Harris]

We have drawings for a storm pump station that show the following:
The drawings show installing (2) 2" underground rigid conduits, for pump cables, from a wet well with no sealoffs, then 30' into the bottom of (1) N7 junction box, then nipple out the top of the N7 JB, then sealoff, then nipple into the bottom of a N4X control enclosure. When the N7 JB is opened, the same classification of the wet well is now at the N7 JB, and at the control enclosure? Are there any NEC requirements placing the sealoffs to be the first fitting out of the ground? Is there any reason for the N7 JB at all?

 

[rbalex]

Re: Why N7 junction box

This does sound like an unusual design. My first question would be, ?Is the area classification properly documented, as required by Section 500.4(A)??

Where the seals then belong is largely a matter of how the area is classified; without that documentation, it?s hard to say.