Parallel conductors in same conduit
- Thread starter lizzie14
- Start date
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- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Re: Parallel conductors in same conduit
Yes, in fact theoretically it's preferable. See Sections 300.3(B)(1) and 310.4 for specifics.
Yes, in fact theoretically it's preferable. See Sections 300.3(B)(1) and 310.4 for specifics.
- Location
- Massachusetts
Re: Parallel conductors in same conduit
Yes you can, I prefer not to as you have to derate the conductors.
Yes you can, I prefer not to as you have to derate the conductors.
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: Parallel conductors in same conduit
I am going to have to ask for a clarification, as I smell a miscommunication in the making.
When you mention parallel conductors in the same raceway, do you mean:
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What is the issue that you are trying to resolve?
I am going to have to ask for a clarification, as I smell a miscommunication in the making.
When you mention parallel conductors in the same raceway, do you mean:
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- <font size="2" face="Verdana, Helvetica, sans-serif">Three phase or single phase?</font>
- <font size="2" face="Verdana, Helvetica, sans-serif">Including a total of four or more current-carrying conductors in the same conduit?</font>
- <font size="2" face="Verdana, Helvetica, sans-serif">Putting only the parallel Phase A conductors in one conduit, all the parallel Phase B conductors in a second conduit, and putting all the parallel Phase C conductors in a third conduit?</font>
What is the issue that you are trying to resolve?
- Location
- Massachusetts
Re: Parallel conductors in same conduit
Charlie I am not trying to further confuse the original question but there is a place in the NEC that allow separate phases in separate raceways. I have taken advantage of when it helped me.
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 works well from a padmount transformer outside to the switch gear inside.
Charlie I am not trying to further confuse the original question but there is a place in the NEC that allow separate phases in separate raceways. I have taken advantage of when it helped me.
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 works well from a padmount transformer outside to the switch gear inside.
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Re: Parallel conductors in same conduit
***Sigh*** I still don't think it's all that clear; i.e., there are too many ways to interpret "... each portion of the paralleled installation..." without already knowing what it means.
Interestingly enough, I think Bob's reference to the exception is usually the first real clue that you need to do something "different" with parallel conductors in multiple metallic raceways. I think I'm going to propose bringing the 300.20 concepts more clearly into 300.2(B) somehow. I have a year or so to think about it
Yeah, I took the original question too literally with respect to the basic rule in 300.3(B).(Everything together) I probably should have referred to 300.20 too.
***Sigh*** I still don't think it's all that clear; i.e., there are too many ways to interpret "... each portion of the paralleled installation..." without already knowing what it means.Interestingly enough, I think Bob's reference to the exception is usually the first real clue that you need to do something "different" with parallel conductors in multiple metallic raceways. I think I'm going to propose bringing the 300.20 concepts more clearly into 300.2(B) somehow. I have a year or so to think about it
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