buck
Member
- Location
- California
Would derating apply if 12/3 MC is run inside PVC below floor for approx. 15ft? Code section?
Thanks in advance
Thanks in advance
Derating
- Thread starter buck
- Start date
- Status
bphgravity
Senior Member
- Location
- Florida
Re: Derating
Derating for what?
Derating for what?
buck
Member
- Location
- California
Re: Derating
Contractor installed PVC under floor in exam room of medical building and for redundant grounding requirements---instead of breaking out the jackhammer he now wants to run MC(hospital grade) through the PVC to serve a floor recepticle for equiptment.
Contractor installed PVC under floor in exam room of medical building and for redundant grounding requirements---instead of breaking out the jackhammer he now wants to run MC(hospital grade) through the PVC to serve a floor recepticle for equiptment.
pierre
Senior Member
- Location
- Westchester County, New York
Re: Derating
330.10 Uses Permitted.
(7) In any raceway
It is permitted, and I do not see a need to apply ampacity adjustment for 3 and less current carrying conductors.
330.10 Uses Permitted.
(7) In any raceway
It is permitted, and I do not see a need to apply ampacity adjustment for 3 and less current carrying conductors.
Re: Derating
Buck,
I agree with Pierre and Bphgravity that derating would not be an issue with the number of current carrying conductors but is it possible that this "hospital grade MC Cable" is actually AC cable?
If so, I do not see a similar provision to allow it to be installed in a raceway in article 320. Secondly if this PVC is installed in a slab (this being a wet location as defined in article 100) the AC cable, or MC cable for that matter unless 330.10(11) could be met, could not be used for the application.
Perhaps there is more to the story?????
Buck,
I agree with Pierre and Bphgravity that derating would not be an issue with the number of current carrying conductors but is it possible that this "hospital grade MC Cable" is actually AC cable?
If so, I do not see a similar provision to allow it to be installed in a raceway in article 320. Secondly if this PVC is installed in a slab (this being a wet location as defined in article 100) the AC cable, or MC cable for that matter unless 330.10(11) could be met, could not be used for the application.
Perhaps there is more to the story?????
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Re: Derating
Where is Paul Harvey when we need him?!
pierre
Senior Member
- Location
- Westchester County, New York
Re: Derating
330.10(11) In wet locations where any of the following conditions are met:
c. The insulated conductors under the metallic covering Are listed for use in wet locations.
That would be THHN/THWN type conductors
330.10(11) In wet locations where any of the following conditions are met:
c. The insulated conductors under the metallic covering Are listed for use in wet locations.
That would be THHN/THWN type conductors
Re: Derating
I agree with you 100% Pierre. Most of the "hospital grade MC" I have seen is actually AC cable. I had a similar situation in a dentist office in which PVC was ran in the slab and a similar "fix" was proposed to satisfy 517.13 although the same problems I listed in my previous post existed.
I agree with you 100% Pierre. Most of the "hospital grade MC" I have seen is actually AC cable. I had a similar situation in a dentist office in which PVC was ran in the slab and a similar "fix" was proposed to satisfy 517.13 although the same problems I listed in my previous post existed.
buck
Member
- Location
- California
Re: Derating
Great points guys. Also thought of how they would connect each end(to stay in compliance with redundant grounding) if run through PVC.
Anyway, thanks again for your help.
Great points guys. Also thought of how they would connect each end(to stay in compliance with redundant grounding) if run through PVC.
Anyway, thanks again for your help.
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