Upsized EGC

[charlie b]

I campaigned for a change to this rule for several cycles. My issue was with the language that said "where conductors are increased." It did not say "increased from what." If I install #10 wires, how could I know whether that was an "increase"?

The present language tells me that if I have five 20 amp single phase circuits in the same conduit, I could not legally use #12 AWG, because the ampacity of that conductor had to be derated to 50% of 30 amps. So the minimum size that has sufficient ampacity under these conditions of use is a #10. So using #10 is not an "increase." Result: #10 ungrounded and #12 EGC.

 

[RumRunner]

I campaigned for a change to this rule for several cycles. My issue was with the language that said "where conductors are increased." It did not say "increased from what." If I install #10 wires, how could I know whether that was an "increase"?

Increasing something must have some established bedrock reference in order to proceed from what we might call INCREASE.

Without this info we cannot say whether it is increase or decrease.

“If I install #10 wires, how could I know whether that was an increase”.

This borders on a philosophical question that only you can answer.

The language that said: “where conductors are increased” is the premordium of the dilemma that followed. . . after the missing reference.

You can't increase something from nothing.

 

[ggunn]

"sufficient ampacity" certainly includes ampacity corrections for ambient temperature though.

As is ampacity correction for CCCs in a raceway, which is, after all, another elevated temperature derate. I agree with others that in the example I posted the EGC need only be upsized between the two boxes and not between the box closer to the service and the service.