Cost of larger cable vs additional conduit in design consideration.

[Pitt123]

For a design consideration I am trying to determine what would be the cheaper cost between running one conduit with upsized (for de-rating) conducotrs or two sets of conduit for with the circuits split up between conduits.

So my two options are:

1) Run (1) 1-1/4" conduit with (4) circuits sized at #4 to account for de-rating with conduit fill and temp.

2) Run (2) 1" conduits with (2) circuits each sized at #8 to account for de-rating with conduit fill and temp.

I would think because of the cost of copper that running the two conduits in option #2 would be the least costly but I'm not exactly sure how the cost and labor for conduit factor into this?

Can anyone offer a suggestion?

By the way the 4 circuits are idential at 30A and in the same location.

 

[Dennis Alwon]

You need to do a cost analysis of the two. Don't forget the extra labor to run the extra conduit. Off the top of my head I would say choice one is cheaper.

 

[iwire]

I would (and have) done what Dennis suggests

In my case for 400 amp feeders two conduits and two sets worked out much cheaper than one conduit and one large set.

But I have no idea how it would play out in the sizes you are asking about.

 

[JWCELECTRIC]

Check out prices on AL vs Cu, may save you some.