duct bank

[mannyb]

We have a set of drawings showing the load side of xfmr giving a detail for duct bank to service entrance gutter. 8-4'' conduits. There is no detail for anyother conduit run that laid underground. We have 6-4'' conduits from SE to MDP2 less than 50' or directly behind service gutter and 2-4'' conduit about 200' to MDP1 . There isnt a detail or notes for this mdp1 or 2 would it be ok to think we can just dig trench and throw in conduit or should we continue the duct bank for mdp1 and 2?

Question #2. If you had a chance to install conduit in foundation before poured concrete would to avoid running overhead? I sometimes find that helpful and PITA especially if I didnt do the work. If I end up on some else job they put to many 90s or didnt glue it right and I end up getting extra work.

 

[Cow]

If the detail showed 8-4" conduits, which we typically use for our 3000 amp services, we usually end up 2 high, 4 wide, using chair bases and intermediates.

To answer your second question, we do underground everywhere possible. I like the clean look of no exposed conduit. I also like getting from A to B as the crow flies, which is a heck of a lot easier to do underground, than following all the building lines when you run overhead. Plus it's faster and cheaper in my experience.

 

[mannyb]

If the detail showed 8-4" conduits, which we typically use for our 3000 amp services, we usually end up 2 high, 4 wide, using chair bases and intermediates.

To answer your second question, we do underground everywhere possible. I like the clean look of no exposed conduit. I also like getting from A to B as the crow flies, which is a heck of a lot easier to do underground, than following all the building lines when you run overhead. Plus it's faster and cheaper in my experience.

There is only a detail for load side of POCO xfmr to 3000a service. it doesnt showing any detail between service and feeders to MDP 1 or 2 would you say we can just install conduit as needed and doesnt necessary need to be a duct bank set up? I would like for it to be done as professiional as possible without to much of the details

 

[DAWGS]

I would send an RFI to the engineer before I guessed at anything. He may tell you how he wants it done or he may give you options.

 

[ron]

The layout of the 6-4" or 2-4" is important to how the ampacity of the conductors work out.

For example, if the ampacity is based on Detail 3 from Annex B, then that would tell you the spacing of the conduit and the max depth below grade.

You need to either figure it out yourself and make sure the ampacity works out or RFI the EOR.