Separate phases in separate conduits.......and # wires per lug....

[dionysius]

1200 A to be run from 1000kVA 480Y/277 utility XFR SEC to SWBRD.
Breaking it up into 4 x 300A parallel runs.
So using 4 PVC Sched 80 conduits which will be located beside each other and underground.

Question A
Can the separate phases occupy same conduit???? :?

In other words:
Can all phase A be in first conduit?
All phase B in second conduit?
All phase C in third conduit?
All neutrals in fourth conduit?
​

I believe I have seen this allowed per NEC if conduit is plastic.
It would make for very neat and organized wiring.


Question B
Are two wires allowed per lug???:?

 

[jusme123]

 

[don_resqcapt19]

...
Question B
Are two wires allowed per lug???:?

Only the lug can tell you. Lugs suitable for use with more than one conductor must be identified as suitable for such use.

110.14(A) ... Terminals for more than one conductor and terminals used to connect aluminum shall be so identified.

 

[dionysius]

View attachment 15136

What a beautiful picture. Tres magnifique!!!!! Thank you Sir.

I will check with Inspector before I implement. From a technical standpoint I see no problem as long as the conduits are close together as in pic for electrical field containment.

When is firestop or water sealant required in such an installation???? Anybody know??? Any conduit termination bushings specified by NEC as shown here. Why not just the plain plastic cleanly cut in such a terrain vertical install.

 

[iwire]

What a beautiful picture. Tres magnifique!!!!! Thank you Sir.

I will check with Inspector before I implement. From a technical standpoint I see no problem as long as the conduits are close together as in pic for electrical field containment.

When is firestop or water sealant required in such an installation???? Anybody know??? Any conduit termination bushings specified by NEC as shown here. Why not just the plain plastic cleanly cut in such a terrain vertical install.

There are tight limitations on doing this.

Also keep in mind that four current carrying conductors in a single conduit requires derating.

 

[electrofelon]

View attachment 15136

Someday I will get to pull isolated phases....every time I pull traditional parallel runs I think this will be the time I can make it look super neat AND obey the same length rules....fail everytime

 

[lauraj]

300.3(B)(1) Exception allows this.

 

[iwire]

300.3(B)(1) Exception allows this.

Yes under very restrictive conditions.

 

[jumper]

Someday I will get to pull isolated phases....every time I pull traditional parallel runs I think this will be the time I can make it look super neat AND obey the same length rules....fail everytime

Never pulled these either. Plans never call for it.

 

[don_resqcapt19]

...Any conduit termination bushings specified by NEC as shown here. Why not just the plain plastic cleanly cut in such a terrain vertical install.

See 352.46.

 

[dionysius]

This may help re termination with PVC conduit:

http://www.electrical-contractor.net/forums/ubbthreads.php/topics/107262/Terminating_PVC.html