2005 code Article 300.20

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soccerdude

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From Article 300.20 is it saying I can run 4 parallel PVC conduits ( that is all all PVC. 90's everything) from a pad mount transformer to a free standing switch, going through no metal. In each of these PVC conduit can I just put one phase of conductors. Like all the A phase in one conduit? All B phase in another and so on?
Or is it addressed some where else. I thought I saw something about it years ago. Thank you
 
Induction

Induction

No, all phase conductors and where used the neutral shall be grouped.
Same conduit regardless whether metal or non metallic.
 
300.3(B)(1) Exception: Conductors installed in nonmetallic raceways run underground shall be permitted to be arranged as isolated phase installations. The raceways shall be installed in close proximity, and the conductors shall comply with the provisions of 300.20(B)

This is the exception that bdarnell referenced in his earlier post. This exception allows conductors to be paralleled in non-metallic raceways and arranged by phases ie. all the same phase conductors in one conduit.

Chris
 
Re: Induction

Re: Induction

Gmack said:
No, all phase conductors and where used the neutral shall be grouped.
Same conduit regardless whether metal or non metallic.
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gmack that is the general rule in 300.3(B).

But take a look at 300.3(B)(1) Exception as Brad mentioned.


300.3(B)(1)Exception: Conductors installed in nonmetallic raceways run underground shall be permitted to be arranged as isolated phase installations. The raceways shall be installed in close proximity, and the conductors shall comply with the provisions of 300.20(B).
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I have done this a couple of times from a pad mount transformer to the service gear.
 
Iwire

Iwire

Iwire, fair enough, I scanned that article for that, but missed. Tri foculs failed me again.

So educate me, why do this or do it this way?
 
G mack, when it's done this way your phase conductors are already the same length and it eliminates the looping at the terminations. Much easier to deal with.
 
So I gather the intent is to simplify the installation process. I suppose it would be up to the AHJ to determine what constitutes "close proximity"?
 
Re: Iwire

Re: Iwire

Gmack said:
Iwire, fair enough, I scanned that article for that, but missed. Tri foculs failed me again.

So educate me, why do this or do it this way?
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gmack I stumbled on this exception one day while reading the NEC, well it was odd and stuck with me.

Next thing I know I have to wire a 3000 amp service, the lugs for the gear where on the bottom close to the floor and the thought of criss crossing eight sets of 600s in the limited space was not interesting.

By going isolated phase the only criss crossing was done out at the pad mount where we had plenty of room.

Not more that a year or two later I ended up doing the same thing for the same reason.

Here is a picture of the gear, the incoming lugs are about 6" above my buddies left hand. (Its dead gear folks)

Service2.jpg
 
charlie b said:
I suppose it would be up to the AHJ to determine what constitutes "close proximity"?
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Both times the raceways where run on 'spacer chairs' that provide about a 2" space between the conduits.

The phase arrangement was like this.

N A B C

N A B C

Truthfully I did not hear until after these jobs where complete that this may not be have been a good decision on my part.
 
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