Wiring codes/standards for small signal?
Wiring codes/standards for small signal?
(OP)
I wonder if there are any codes/standards out there to address industrial equipment, specifically the small-signal control circuitry and wiring they often utilize.
For instance, I know that it is good practice, but is there a code or standard out there that actually says to keep AC and DC signal wires separate? And when wiring small signals such as to PLCs, is there a code/standard that specifies what wire sizes to use? The NEC doesn't really show anything above 18 gauge, which handles 18 Amps. What about color? Does it matter? Or issues such as strapping the wire or harness properly when running to a hinged panel, to avoid stressing the cables.
There are a ton of little issues that arise for which I've never seen a comprehensive guide/standard. What to do?
For instance, I know that it is good practice, but is there a code or standard out there that actually says to keep AC and DC signal wires separate? And when wiring small signals such as to PLCs, is there a code/standard that specifies what wire sizes to use? The NEC doesn't really show anything above 18 gauge, which handles 18 Amps. What about color? Does it matter? Or issues such as strapping the wire or harness properly when running to a hinged panel, to avoid stressing the cables.
There are a ton of little issues that arise for which I've never seen a comprehensive guide/standard. What to do?






RE: Wiring codes/standards for small signal?
Also, NFPA publishes NFPA 79: Electrical Standard for Industrial Machinery that has a lot of useful information. If you're going to be manufacturing industrial equipment or control panels, I recommend it.
xnuke
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Wiring codes/standards for small signal?
How complete is NFPA 79 in addressing the numerous issues that arise in industrial machine design? Does it, for instance, have ampacity tables for smaller gauge wires? Does it address the issue of running AC and small signal lines near each other?
Thanks.
RE: Wiring codes/standards for small signal?
For a rough idea of what NFPA 79 contains, you can view a draft here www.nepss.org/NFPAtc79/draft_NFPA79_2002... but I highly recommend buying the 2002 standard. It's about $35 US.
xnuke
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Wiring codes/standards for small signal?