Riser Cable in Conduit

[Vinnyw]

I have a system which operates at 56V, but has 600W (foldback current limited by a solid-state device) of capability per output channel, so this is not any of Class 1, 2 or 3. It is a Listed UL 2108 system.

For an installation where the cable will be concealed behind construction materials, is it permissible to use 300V riser (CMR) cable that is in conduit (EMT or flexible metallic?)

 

[don_resqcapt19]

Looks like 411.6(D)(3) requires a Chapter 3 wiring method. CMR is not a Chapter 3 wiring method.

 

[Vinnyw]

What type of cable can be used? There is both the 56VDC, 600W power conductors and an RS-485 twisted pair in the proposed riser cable.

 

[hbiss]

Looks like 411.6(D)(3) requires a Chapter 3 wiring method. CMR is not a Chapter 3 wiring method.

Is that 2014 or 17 Don? I'm not seeing that in the 2011 which seems to indicate CL2 but I'll take your word for it.

OP- The protocol here is that if the power supply does not indicate via its label that it is CL2 or CL3 then you must assume that you have to use a Chapter 3 wiring method.



-Hal

 

[don_resqcapt19]

Is that 2014 or 17 Don? I'm not seeing that in the 2011 which seems to indicate CL2 but I'll take your word for it.

OP- The protocol here is that if the power supply does not indicate via its label that it is CL2 or CL3 then you must assume that you have to use a Chapter 3 wiring method.



-Hal

It is from the 2017 code, but even in 2011, you could only use the CL2 cable if the power supply was a Class 2 power supply. The OP seems to indicate that the power supply is not a Class 2 supply. Chapter 9, Table 11A limits the maximum power of a Class 2 power supply to much less than the 600 watts the OP says he has.

 

[don_resqcapt19]

What type of cable can be used? There is both the 56VDC, 600W power conductors and an RS-485 twisted pair in the proposed riser cable.

You need two conduits the way I read the code rules.