Fred if these circuits are 20 amps you just made it. [Linked Image]

In the pipe you describe you have 8 current carrying conductors of 12 AWG.

Apply the 70% adjustment required and you end up with a 21 amp rated conductor.

If you had not used MW circuits you would have had a problem, once you get to 10 current carrying conductors it would be a 50% adjustment resulting in 15 amp rated 12 AWG.

I asked because I see these derating rules forgotten about often.

Bob

Bob Badger
Construction & Maintenance Electrician
Massachusetts