Pull Box in Class I, Div. 2 Building & Below Grade Conduit Duct Bank

scrub12

Member
Location
Cleveland, OH
Occupation
Electrical Engineer
Looking for some confirmation on a design:

I have a below-grade conduit duct bank from Pull Box #1 to another Pull Box #2 (Approx. 150'). Pull Box #1 is located in an unclassified area. Pull Box #2 will be in a Class I, Div. 2 rated building. I plan on running PVC Conduit between the pull boxes in a concrete-encased duct bank 24" below grade. Reading the Code I believe this is acceptable however I will need to transition to Rigid Conduit for the last 24" of the underground run to the emergence of Pull Box #2 (Since it is located in the Class I, Div. 2 area). Conduit seals would be required at the stub-up location in Pull-Box #2. A standard NEMA 1 enclosure would be acceptable for Pull Box #2. Is my code interpretation correct? I appreciate any help you can provide!
 

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
Looking for some confirmation on a design:

I have a below-grade conduit duct bank from Pull Box #1 to another Pull Box #2 (Approx. 150'). Pull Box #1 is located in an unclassified area. Pull Box #2 will be in a Class I, Div. 2 rated building. I plan on running PVC Conduit between the pull boxes in a concrete-encased duct bank 24" below grade. Reading the Code I believe this is acceptable however I will need to transition to Rigid Conduit for the last 24" of the underground run to the emergence of Pull Box #2 (Since it is located in the Class I, Div. 2 area). Conduit seals would be required at the stub-up location in Pull-Box #2. A standard NEMA 1 enclosure would be acceptable for Pull Box #2. Is my code interpretation correct? I appreciate any help you can provide!
Assuming Pull Box #2 is not subject to Section 501.15(B)(4), an enclosure otherwise recognized as suitable for the location is acceptable.

I am curious how the room's classification PB#2 is installed in was determined; but, if it is a legitimate determination, the above stands.
 

scrub12

Member
Location
Cleveland, OH
Occupation
Electrical Engineer
Assuming Pull Box #2 is not subject to Section 501.15(B)(4), an enclosure otherwise recognized as suitable for the location is acceptable.

I am curious how the room's classification PB#2 is installed in was determined; but, if it is a legitimate determination, the above stands.
Thank You!

As far as the area classification for the area in which Pull Box #2 is installed. It will be, in the future, considered a flammable storage room.
 
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