CharlieSW
Member
- Location
- Annapolis, MD
In situations where contrete encased duct banks enter into a below grade structure or vault that is a classified hazardous location - where do the seal fitting go?
duct bank entrance into buildings
- Thread starter CharlieSW
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kingpb
Senior Member
- Location
- SE USA as far as you can go
- Occupation
- Engineer, Registered
Try 501.15, exception #2.
Try 501.15, exception #2.
I see the exception as a call-out for cable blocking kits. I view the question as a conduits entering an enclosure.
Can the OP post a drawing or explain how it is these conduits enter the space, and where they are going to? Thanks in advance.
I see the exception as a call-out for cable blocking kits. I view the question as a conduits entering an enclosure.
Can the OP post a drawing or explain how it is these conduits enter the space, and where they are going to? Thanks in advance.
CharlieSW
Member
- Location
- Annapolis, MD
This is for a wastewater treament plant. Generally the conduits penetrate a below grade valve vault (C1, D2) and go into a junction box. Or in the case where it is building serving as a service to a panelboard, I would guess that the seal woudl go 18" upstreams of the conduit entrance?
I'm envisioning something like an MCC at the non classified end of the run on one end (with raceways out the bottom). At the other end , can you convert from PVG to GRC for last for last two feet of UG and up the wall into bottom EYS's , (or EYD's depending upon condensation potential in raceway)? Don't forget 25% fill rule for the seal offin sizing fitting.
Stick a factory nipple (GRC) in between EY and box/panel bottom.If it is extremely wet area, perhaps a myers hub at the box. I see this as low risk area in regard to explosion potential, but it looks pretty safe from a keyboard. With consideration to the environment are you just running into the bottom of 4x box/panel?
Beauty of this forum is that there are others here for serious brainstorming this problem. As a matter of fact, a moderator with the handle of rbalex that is an EE professional engineer I believe might have some possible solutions in regard to this. Just a good guess, but fair one I should hope.
Stick a factory nipple (GRC) in between EY and box/panel bottom.If it is extremely wet area, perhaps a myers hub at the box. I see this as low risk area in regard to explosion potential, but it looks pretty safe from a keyboard. With consideration to the environment are you just running into the bottom of 4x box/panel?
Beauty of this forum is that there are others here for serious brainstorming this problem. As a matter of fact, a moderator with the handle of rbalex that is an EE professional engineer I believe might have some possible solutions in regard to this. Just a good guess, but fair one I should hope.
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