AC and DC in Same Raceway (Derating Question)

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chukkyi

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Location
MD
Existing
I have power (#12's) and control wires (#14's) in the same RGS conduit feeding 4 signs. Power is off a 20A breaker at 120VAC 1PH (+120V, -120C, GND) (Non-continuous). Control is (+12VDC, +12VDC, -12VDC) (Continuous). All four signs are spliced into the same AC feed for their 5A motors, but have their individual control lines, which is 3-#12 & 12-#14's in one 1"C for over 100' before terminating into their individual JB's with (3-#12 & 3-#14) for each sign.

Proposed
I'm getting replacement signs with 20A Motors (worst case), and need to feed them through the same 1" conduit (embedded in structures and concrete). Control is remaining +12VDC. I am aware of the provision of NEC Article 725 class 1 or 2 which i believe covers this case for allowing both in same raceway.

Question
  1. Would the control wires be considered as current carrying conductors for the sake of derating?
  2. I'm looking to up the breaker size and pull new power wires (possibly control also) through that 1"C, how will derating affect this?
 
As far as I know if the control circuits carry current then they must be counted-- I don't know of any exception for them
 
chukkyi said:
All wires are THHN btw.
Click to expand...

What about the second paragraph of 310.15(B)(3)(a)...

Where conductors of different systems, as provided in
300.3, are installed in a common raceway or cable, the
adjustment factors shown in Table 310.15(B)(3)(a) shall
apply only to the number of power and lighting conductors
(Articles 210, 215, 220, and 230).


 
Dennis Alwon said:
As far as I know if the control circuits carry current then they must be counted-- I don't know of any exception for them
Click to expand...

What about the second paragraph of 310.15(B)(3)(a)...

Where conductors of different systems, as provided in
300.3, are installed in a common raceway or cable, the
adjustment factors shown in Table 310.15(B)(3)(a) shall
apply only to the number of power and lighting conductors
(Articles 210, 215, 220, and 230).
 
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