Results 1 to 6 of 6

Thread: Riser Cable in Conduit

  1. #1
    Join Date
    Aug 2018
    Location
    Charlotte, NC, USA
    Posts
    2

    Riser Cable in Conduit

    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?)

  2. #2
    Join Date
    Feb 2003
    Location
    Illinois
    Posts
    23,747
    Looks like 411.6(D)(3) requires a Chapter 3 wiring method. CMR is not a Chapter 3 wiring method.
    Don, Illinois
    (All code citations are 2017 unless otherwise noted)

  3. #3
    Join Date
    Aug 2018
    Location
    Charlotte, NC, USA
    Posts
    2
    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.

  4. #4
    Join Date
    Jun 2003
    Location
    Hawthorne, New York NEC: 2014
    Posts
    3,887
    Quote Originally Posted by don_resqcapt19 View Post
    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

  5. #5
    Join Date
    Feb 2003
    Location
    Illinois
    Posts
    23,747
    Quote Originally Posted by hbiss View Post
    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, Illinois
    (All code citations are 2017 unless otherwise noted)

  6. #6
    Join Date
    Feb 2003
    Location
    Illinois
    Posts
    23,747
    Quote Originally Posted by Vinnyw View Post
    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.
    Don, Illinois
    (All code citations are 2017 unless otherwise noted)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •