Current Carrying Conductor Correction Factors

[czars]

For years I have believed that the correcton factors of Tables 310.16-20 were to be applied to the ampacities listed in the 75 degree columns. However, I can find no code reference to that effect. Am I confused or is there a reference somewhere?

 

[mcclary's electrical]

For years I have believed that the correcton factors of Tables 310.16-20 were to be applied to the ampacities listed in the 75 degree columns. However, I can find no code reference to that effect. Am I confused or is there a reference somewhere?

They are to be applied to the 90 degree chart for derating

 

[augie47]

actually, I believe you apply the correction to the applicable conductor insulation, 90? conductors such as THHN would use the factors listed below the 90? wire, 75? insulation, such as RHW, would use the factors in that column.

 

[mcclary's electrical]

actually, I believe you apply the correction to the applicable conductor insulation, 90? conductors such as THHN would use the factors listed below the 90? wire, 75? insulation, such as RHW, would use the factors in that column.

Good point Augie, I tend to forget that because almost everything I use starts at 90:roll:

 

[charlie b]

I don't have my book handy, but I believe the code reference is somewhere in the vicinity of 110.14(C).

 

[czars]

Current Carrying Current Correction Factors

Current Carrying Current Correction Factors

Thanks for the info. I always appreciate the help of those more experienced than me.