De-rating when there is very little current

[winnie]

The two travelers of a three way count as a single current carrying conductor, because one or the other carries current at any given time.

I claim that we have an analogous situation here.

Just reread the code section. I am forced to agree, as written these conductors count as cccs. However the physics of the situation argues that they should not count.

Jon

 

[I_am_STILL_learning]

Maybe it would be better to go with 10AWG THHN. With the ground they would fit in the EMT. That would give the whole 20A--well 16A continuous. That might be helpful instead of 12A continuous.

 

[kwired]

The two travelers of a three way count as a single current carrying conductor, because one or the other carries current at any given time.

I claim that we have an analogous situation here.

Just reread the code section. I am forced to agree, as written these conductors count as cccs. However the physics of the situation argues that they should not count.

Jon

But for the OP's case they are still carrying less than the conductor ampacity even after adjustments are made - that leaves us with plenty of conductor and just possible overcurrent protection rules issues, OP probably should have 15 amp OCPD instead of 20, but his conductors have plenty of capacity to carry the load.

 

[wwhitney]

How about something like "where two or more current carrying conductors are protected by a single overcurrent device, and the currents in them are additive at the overcurrent device, they may be counted as a single current carrying conductor."

OK, I submitted a PI for the above.

Cheers, Wayne