Applying different voltages in Multicore Cables

[NickParker]

1. Can different AC voltages (24V AC, 120V AC, 230V AC) be passed through the different cores of the same multicore cable?
2. Can both AC & DC voltages (24V AC, 120V AC, 110V DC, 24V DC) be passed through the different cores of the same multicore cable?
Should I run shielded cables if I do both (1) & (2)?
I think this is not a NEC code violation, as NEC 300.2(C)(1) permits it, I would like to know, what are the consequences of it?

 

[JG2828]

Here is a similar thread from 2005.

http://www.eng-tips.com/viewthread.cfm?qid=133963

 

[itsmoked]

Hi JG. Consider copying and pasting the thread number instead of the link as it {usually} has more info.

Note above the thread 238-433422 (a space added to prevent titling)

thread238-133963


Nick: You can run anything you like thru various wires in a cable with the requirement being all wires must be voltage rated to the highest voltage present.

Should you do this? Usually not! The most important point is to keep control lines away from power conductors and keep signal lines, as in sensor wires, away from both control and power conductors or you will pay for being cheap over and over and over again, with the resulting flaky performance the system will demonstrate. You don't even want these three classes in the same conduit in different cables. You really don't even want them running the same path unless they are metallicly isolated.

Certain systems do require sharing all these signals in a single cable. However, those systems must embrace the mix from a fundamental position in the system design. The system design will focus a lot of engineering specifically on dealing with the resulting interference. This is on the level of constraining signals, carefully filtering them, and only reading sensor signals at specific times when switching transients are forced not to occur or are known not to be occurring. This kind of system design is not usually available in typical commercial or industrial system integrations but only in engineered systems where one controller is in-charge of everything passing into and out of a cable.

Keith Cress
kcress -

http://www.flaminsystems.com