Do we really have to go to 725 to find out that we don't have to count the control wires as current carrying conductors? It looks to me like 310.15(B)(2)(a) tells us we don't have to count the control wires.
That is a good question. Here is my logic:
For the control wires to be allowed within the conduit with the power conductors, the control wires must be class 1.
Class 1 conductors are covered in
725.
90.3 Code Arrangement . ... Chapters 1 through 4 apply
except as
amended by Chapters 5, 6, and 7 for the particular conditions. ...
725.51 Amends
310.15(B)(2)(a) by adding two additional conditions:
725.51 Number of Conductors in Cable Trays and Raceway,
and Ampacity Adjustment.
(B) Power-Supply Conductors and Class 1 Circuit Conductors.
Where power-supply conductors and Class 1 circuit
conductors are permitted in a raceway in accordance
with 725.48, the number of conductors shall be determined
in accordance with 300.17.
The ampacity adjustment factors
given in 310.15(B)(3)(a) shall apply as follows:
(1) To all conductors where the Class 1 circuit conductors
carry continuous loads in excess of 10 percent of the
ampacity of each conductor and where the total number
of conductors is more than three
(
2) To the power-supply conductors only, where the Class
1 circuit conductors do not carry continuous loads in
excess of 10 percent of the ampacity of each conductor
and where the number of power-supply conductors is
more than three
You guys have been suggesting that I read the code carefully, in this case I tried to catch the additional conditions hidden in
725.
If there has been only three power conductors, then I would have needed to count the control wires.
If the control wires carried 2 amps, then I would have needed to count the control wires.
None of these rules are in
310.15(B)(2)(a).
