Parallel conductors

[arnettda]

If I run 3/0 parrelled for a 400 amp service in a gutter for 15 ft can I drop down out of the gutter to the disconect in two pipes or do I need to use just one. Is there an advantage of using two pipes over 1 or vice versa? Derating?

 

[chris kennedy]

How long are the "pipes"?

 

[infinity]

One conduit over 24" long will trigger derating factors for the conductors. If more than 24" you should probably use two conduits.

 

[arnettda]

So for paralled conductors in EMT over 24" you should always use two pipes?
Where can I read this? Thanks

 

[infinity]

so for paralled conductors in emt over 24" you should always use two pipes?
Where can i read this? Thanks

310.15(b)(2).

 

[celtic]

So for paralled conductors in EMT over 24" you should always use two pipes?
Where can I read this? Thanks

310.15(b)(2).

It really has nothing to with PARALLELED....
The trigger is CURRENT CARRYING CONDUCTORS.

 

[arnettda]

One conduit over 24" long will trigger derating factors for the conductors. If more than 24" you should probably use two conduits.

Sorry I did not read it close enough. So derating and pipe size are really the only two concerns for having all conductors in one pipe.

 

[Cow]

Sorry I did not read it close enough. So derating and pipe size are really the only two concerns for having all conductors in one pipe.

I would think the cost of using larger wire would be a concern too when doing long pulls...

 

[infinity]

It really has nothing to with PARALLELED....
The trigger is CURRENT CARRYING CONDUCTORS.

That's true, but I don't think that I said paralleling has anything to do with it.

 

[augie47]

Sorry I did not read it close enough. So derating and pipe size are really the only two concerns for having all conductors in one pipe.

If you use two pipes, be sure you have each phase and the grounded conductor (if present) in each pipe (as opposed to both A phases in 1 pipe, etc).
also if you are installing an equipment grounding conductor, it must be in each raceway.

 

[hardworkingstiff]

If you use two pipes, be sure you have each phase and the grounded conductor (if present) in each pipe (as opposed to both A phases in 1 pipe, etc).
also if you are installing an equipment grounding conductor, it must be in each raceway.

And doesn't it need to be sized to the sum of the phase conductors (not just the conductors in the one conduit)?

 

[celtic]

That's true, but I don't think that I said paralleling has anything to do with it.

It was an unrequested mandatory Capt. Obvious appearance.:grin:

 

[benaround]

And doesn't it need to be sized to the sum of the phase conductors (not just the conductors in the one conduit)?

Good point, if using two conduits, a full sized EGC would be required in each.