I have a large service panelboard at a BP gas station and convenience store. All the conduits from the island dispensers run back to the open bottom floor mounted service panelboard on the inside, and the seal off fittings are the first fittings located just above the concrete slab. I can't find a code section that would not permit this installation.

1. The panelboard is not an explosionproof enclosure.
2. The panelboard is located in an unclassified area.

What code section will I use to reject the seal off's for being inside the panelboard in article 500 and 501?

Mike, I just got in from the field so I have to clean up and then I will go out and get my code book and take a stab on this one.

What is immediately coming to my mind is not in 500 or 501. It is somewhere in Switchboards and Panelboards. There can only be a 3" rise inside a switchboard or panelboard and I do believe that the code article stipulates that fittings are most definitely included in this measurement. You will have to double check me.

Just quick thinking. I could be wrong but that's my immediate thought. I will post back later as soon as I can.

I believe Nick is refering to Section 408.10

Yup, that's the one. I just looked it up and it applies to switchboards, floor-standing panelboards, or similar enclosures. The seal off is a fitting so I would take a measure and if it is more than 3" rise inside the enclosure, then I would tag the job. It might be close, I don't know. Also keep in mind that the minimum wiring space (assuming insulated busbars) shall not be less than 8" from the bottom of the enclosure and bussbars, their supports, or other obstructions, so that is something that might apply.

I will start looking in 500 and 501 also.

Well, I know I always say this, but first I would double check the approved set of plans. A gas station is usually done by an engineer who stamped the plans...see if the contractor complied with the approved drawing, or if he/she took it upon themselves to install the seal offs inside the panelboard on their own.

Then, I went to 500, 501 could find nothing.

Then, I went to 250 because the seal off fitting needs to be grounded in my opinion. 300.10 may also be useful. I don't think 250.86 would apply because one will argue that a seal off is not an enclosure or raceway. But, the term equipment by definition applies to fittings and, would not 250.110 condition 1 apply? I think this contractor screwed up because the only way to bond that fitting is with a short rigid nipple and a bonding bushing (MIG) and by that time they will exceed the 3" maximum rise.

Opinions....?


PS - (off the subject) Since this is a gas station a quick reminder to everyone that the car-vacs at gas stations usually have no listing whatsoever, so be sure to check for a listing at final inspection. A field listing may be in order.

Yep we agree about the 3" rise for the fittings in the panelboard, and the requirement for bonding. That is taken care of before final so they end up being ok.

But again, do we have a code section that would prohibit the seal off fittings from being inside the panelboard per article 500 or 501?

After much research I think that it’s ok.

Mike I am trying to upload the photos you sent but my server is not responding at the moment so I will try again later.


question:
how are they bonding the seal offs?

Here are some photos of the installation that Mike asked me to post:

A nipple will be installed with a bonding bushing and a bonding jumper.

I'm still scrounging around for something in 514 to prevent this installation, but for now how about using 300.15(F)

?