310-16
- Thread starter jociha
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Re: 310-16
John, the column used is the rating of the terminations. There are very few 90deg rated terrminations. Look at article 110.14(C)(1) for general rules.
Now with that said, HVAC equipment and Motors are not "rule of thumb". Look at articles 430 and 440. Conductors in these articles can be protected much higher than 310.16 would seem to allow.
Roger
John, the column used is the rating of the terminations. There are very few 90deg rated terrminations. Look at article 110.14(C)(1) for general rules.
Now with that said, HVAC equipment and Motors are not "rule of thumb". Look at articles 430 and 440. Conductors in these articles can be protected much higher than 310.16 would seem to allow.
Roger
Re: 310-16
Okay,i am not sure i understand if the temp. rating is for the termination point why are certain wire types listed under each column. Reading 430-6 it calls for using 310-15b or c. 315-15b tells me to use 310-16. FPN note 1 states temp. compatability but must we follow a FPN.I understand the 125% rule, and the mocpd, just not the wire sizing after i have my mca. john
Okay,i am not sure i understand if the temp. rating is for the termination point why are certain wire types listed under each column. Reading 430-6 it calls for using 310-15b or c. 315-15b tells me to use 310-16. FPN note 1 states temp. compatability but must we follow a FPN.I understand the 125% rule, and the mocpd, just not the wire sizing after i have my mca. john
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- Massachusetts
Re: 310-16
It's both the wire and the termination which ever is less. If you had a terminal for 90C you would chose by the wire type alone, but as your terminal is 75C you can not go above that temp.
It's both the wire and the termination which ever is less. If you had a terminal for 90C you would chose by the wire type alone, but as your terminal is 75C you can not go above that temp.
jmc
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- Massachusetts
Re: 310-16
Table 310.16 has distinct columns by temperature rating of the specific conductors, 60,75, and 90 degrees C. The ampacities listed under each column is the amount of current the conductor can carry continuously without exceeding the temperature rating of the conuctor under the specific column. The limiting factor as to how much current the conductor can carry when it is connected to an overcurrent device and a load termination, is the temperature rating of the termination. See Section 110.14(C), it is the weak link in the chain.
Table 310.16 has distinct columns by temperature rating of the specific conductors, 60,75, and 90 degrees C. The ampacities listed under each column is the amount of current the conductor can carry continuously without exceeding the temperature rating of the conuctor under the specific column. The limiting factor as to how much current the conductor can carry when it is connected to an overcurrent device and a load termination, is the temperature rating of the termination. See Section 110.14(C), it is the weak link in the chain.
jmc
Member
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- Massachusetts
Re: 310-16
The different temperature values for conductor insulation allows the conductor to be used in elevated temperature and the temperature correction factors can be applied under the specific column. For example #10awg, cu, THHN has 90 degree C insulation has an ampacity of 40 amps.You are permitted to use the correction factors under the 90 degree column, however, if you have 60 degree terminations, the maximum load cannot exceed 30 amps or the new value arrived at after applying correction factors. Hope this helps.
The different temperature values for conductor insulation allows the conductor to be used in elevated temperature and the temperature correction factors can be applied under the specific column. For example #10awg, cu, THHN has 90 degree C insulation has an ampacity of 40 amps.You are permitted to use the correction factors under the 90 degree column, however, if you have 60 degree terminations, the maximum load cannot exceed 30 amps or the new value arrived at after applying correction factors. Hope this helps.
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