Re: Ampacity column in NEC 310-16 -- The discussion forum of theTennessee Chapter

[ Show ]

Support VoyForums

[ Shrink ]

VoyForums Announcement: Programming and providing support for this service has been a labor of love since 1997. We are one of the few services online who values our users' privacy, and have never sold your information. We have even fought hard to defend your privacy in legal cases; however, we've done it with almost no financial support -- paying out of pocket to continue providing the service. Due to the issues imposed on us by advertisers, we also stopped hosting most ads on the forums many years ago. We hope you appreciate our efforts.

Show your support by donating any amount. (Note: We are still technically a for-profit company, so your contribution is not tax-deductible.) PayPal Acct: Feedback:

Donate to VoyForums (PayPal):

[ Login ] [ Contact Forum Admin ] [ Main index ] [ Post a new message ] [ Search | Check update time ]

Subject: Re: Ampacity column in NEC 310-16

Author:
john

[ Next Thread | Previous Thread | Next Message | Previous Message ]

Date Posted: 11:06:22 09/30/04 Thu
In reply to: Monte Mason 's message, "Re: Ampacity column in NEC 310-16" on 15:25:10 10/05/02 Sat

>My opinion would be that it would sound like the 75
>degree column would be the one, unless the load on the
>conductors exceeded the amount calculated on derating
>in note #8. The derating of conductors may start at
>the higher temperature rating before you start
>derating for heat, load, etc. However it must be
>protected with "the weakest link" taken into
>consideration. After derating, the conductor must be
>calculated at the 75 Degree column unless the amperage
>exceeds the amount in that column. In that event, the
>conductor would have to be increased in size.
>>To install 9 conductors in a single raceway 8 of which
>>are current carrying, to supply power and lighting
>>loads. The copper conductors will have THHN insulation
>>and be fused at 20 amps. Considering the note to
>>article 240.4(D) which limits the overcurrent
>>protection on 14,12,and 10AWG conductors, and the fact
>>that these conductors will be terminated to 75 degree
>>C terminals or lugs. Table 310.15(B)(2)(a) requires an
>>adjustment factor of 70% for7-9 current carrying
>>conductors. Ambient temperature is not a factor in
>>this case.
>>Which column of table 310-16 is allowable to use to
>>caluculate the wire size?

[ Next Thread | Previous Thread | Next Message | Previous Message ]