Correction Factors 310.16

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jca0108

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I understand what 110.14(c) says. It says that if its under a 100 amps , I can use a higher temperature rated conductor(THHN), as long as I size it with the 60c column in table 310.16. For example, I have a 50A range receptacle with 60c terminals. If I use THHN, you go to 310.16 and size that wire according to the 60c column because of the terminals, and its a 6 AWG.
Now my question is, what if that receptacle was located in an ambient temperature 100F? Which correction factor column at the bottom of 310.16 would I use, the 90c because of the THHN or 60c because of the terminals?
 
Dennis Alwon

Dennis Alwon

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As the others have said you would use the 90 C for derating or correction factor but you cannot use OCP based on anything other than the 60C rating.

For example, if the amperage after derating would allow OCPD based on the 75C column you could not use that number. You would have to use the 60C column because that is your weakest link.
 
J

jca0108

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Dennis Alwon said:
As the others have said you would use the 90 C for derating or correction factor but you cannot use OCP based on anything other than the 60C rating.

For example, if the amperage after derating would allow OCPD based on the 75C column you could not use that number. You would have to use the 60C column because that is your weakest link.
Click to expand...

what is ocp, ocpd?
 
J

jca0108

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But that means that after the correction,that 75 x .91 = 68.25, that now the conductor is rated at 90c column. How do I know what the ampacity now under the 60c column?
 
augie47

augie47

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In one respect, you really don't care. The purpose is to prevent insulation damage and if you are dealing with 90? insulation, you need only to worry about the values in the 90? column. The 60? rating covers the limits for the termination based on the termination rating.
 
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