multi conductor cables and various voltages

[jcraft]

We have a large piece of automated machinery in our facility that we will be rebuilding. To make the work easier we would like to run multi-conductor cables through the wireways instead of individual conductors to the main centralized junction boxes. These boxes will contain terminal blocks which will feed various 24VDC I/O from the PLC cabinet as well as 120 Volt. My question is should we mix 24VDC and 120 VAC on the same cable or would it be smart to run one cable for all the DC I/O and another cable for all the AC devices. Also, if we use a cable to pick up various motor devices do we need to derate the cable if there are more than so many wires in the cable. Thanks for the help.

 

[itsmoked]

It's always better to separate Low Voltages from Higher Voltages and the longer the run the more important this becomes. That said, 24VDC mixed with 120VAC is probably the least problematic after 24VAC and you likely won't have a problem.

You should do a rough analysis of the current>power>temperature the cables will see to make sure you aren't going to overheat things.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com