Feeder Run In Separate PVC Conduit

[PeteDMC]

A prior electrician (who was fired) ran a 200A 3phase feeder in two separate PVC conduits. (Hot, Hot, Ground) in one conduit and (Hot, Neutral, Ground) in the other. Looks like this may be allowed by 300.3(B)(3) as long as I cut slots in the panel between where the two conduits enter the panel as required by 300.20 B.

Seems crazy, but just want to make sure I am reading code correctly.

Kind Regards

 

[HEYDOG]

A prior electrician (who was fired) ran a 200A 3phase feeder in two separate PVC conduits. (Hot, Hot, Ground) in one conduit and (Hot, Neutral, Ground) in the other. Looks like this may be allowed by 300.3(B)(3) as long as I cut slots in the panel between where the two conduits enter the panel as required by 300.20 B.

Seems crazy, but just want to make sure I am reading code correctly.

Kind Regards

IMO 300.3(b). They all need to be in the same raceway!

 

[infinity]

If I remember correctly iso-phase conductors with PVC had to run into an open bottom switchboard.

 

[tom baker]

That installation will result in overheating of conductors as magnetic fields don’t cancell

 

[PeteDMC]

IMO 300.3(b). They all need to be in the same raceway!

Thanks for the response!

After re-reading the code section carefully noticed "300.3(B) 1 Exception 1" reads:
"Conductors installed in nonmetallic raceways run underground shall be permitted to be arranged as isolated phase, neutral, and grounded conductor installations...."

Still seems wrong, but I think this applies (the conduits are underground)...

 

[synchro]

The arrangement of the OP does not mention paralleled conductors, or isolate all of the phase and neutral conductors from each other, as is required for the 300.3(B)(1) Exception to apply.

 

[PeteDMC]

IMO 300.3(b). They all need to be in the same raceway!

Why doesn't 300.3(B)(3) apply?

Example of 300.3(B)(3)

Does anyone have a picture of an installation of 300.3(B)(3) in compliance with 300.20(B)? Thanks Underground Isolated Phase Installation Here we are looking at three, 4 wire feeders in MI cable using a non-ferris entry into a panel

forums.mikeholt.com

 

[winnie]

300.3(b) exception for NM raceway doesn't apply because this isn't an installation with parallel conductors.

But the physics basis of 300.3(b) does apply.

The issue is unbalanced currents in a raceway causing inductive heating of the raceway, enclosure penetrations, or surrounding rebar in a ductbank.

If you follow the rules for a non parallel isolated phase installation, induction shouldn't be a problem, even without parallel conductors.

 

[wwhitney]

Why doesn't 300.3(B)(3) apply?

It does by any plain reading. If the CMP intended something else, they missed the mark in the language by so much that the intentions are moot.

Cheers, Wayne

 

[don_resqcapt19]

It does by any plain reading. If the CMP intended something else, they missed the mark in the language by so much that the intentions are moot.

Cheers, Wayne

I tried to delete the exception to 300.3(B)(1) because 300.3(B)(3) makes it moot, but the panel did not agree with me.

 

[wwhitney]

I tried to delete the exception to 300.3(B)(1) because 300.3(B)(3) makes it moot, but the panel did not agree with me.

Yes, I saw the post in the thread linked to in post #7. The panel answer is sufficiently obtuse in not referencing 300.3(B)(3) at all that I don't think they really considered what 300.3(B)(3) says.

Cheers, Wayne

 

[synchro]

Perhaps the following in 300.5 Underground Installations might be applicable to the OP's installation. It doesn't seem to exclude more than one raceway on the same circuit as long as all of those circuit conductors are in close proximity in the same trench. I guess "close proximity" might be subject to interpretation.

300.5(I) Conductors of the Same Circuit.
All conductors of the same circuit and, where used, the grounded conductor and all equipment grounding conductors
shall be installed in the same raceway or cable or shall be installed in close proximity in the same trench.

 

[winnie]

Why doesn't 300.3(B)(3) apply?

Example of 300.3(B)(3)

Does anyone have a picture of an installation of 300.3(B)(3) in compliance with 300.20(B)? Thanks Underground Isolated Phase Installation Here we are looking at three, 4 wire feeders in MI cable using a non-ferris entry into a panel

forums.mikeholt.com

My error. 300.3(B)(1) does not apply. 300.3(B)(3) does.

-Jon