I have a question about underground pull boxes. The engineer on the project has been no help. We have 12-4” sch 40 pvc with 4-750kcmil with one 500kcmil. This is feeding a 4000 amp switch. Any info would be great. I do understand the code on pull box sizing with the 8x rule. However, I feel that there should be a way larger underground pull box installed for any maintenance and or repair. Thanks again.
Underground pull box
- Thread starter JDW1307
- Start date
- Location
- New Jersey
- Occupation
- Journeyman Electrician
The 8X is the code minimum. It is useless for pulling in and out of that box. Even for splices within the box it's very tight with 750's. I would opt for a minimum of 48" unless you're 100% sure that you will just be pulling through the box.
Welcome to the Forum
Welcome to the Forum
- Location
- Bremerton, Washington
Ask the engineer to come assist on the pull.
Or bring donuts
Or bring donuts
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
Do they provide sizing? We have used them when the box is specified.
Roughly 300’
It's been awhile but I think Old Castle does, don't remember Quazite doing it, I think we specified sizes to them
- Location
- New Jersey
- Occupation
- Journeyman Electrician
And what is your intended use of the pull box (splicing, pull through) or is it just to satisfy the 360° rule?
There is a situation on the project where the first design was approved. Now the owners have decided to sell the adjacent land that are proposed route was running through. Trying to satisfy this design/owner mistake.