Running control wiring in power conduit for EV Charger amperage control. 725.26(B)(1).

[jaggedben]

Would this be suitable?

https://www.wireandcableyourway.com...tation-cable-w-overall-shield-type-tc-er-600v
18/1PR Type TC, Tray Cable, Overall Shield, 600V
Permitted use in Class 1, Division 2 industrial hazardous locations per NEC. Listed Type TC.
Rated at 90°C dry, 75°C wet

Any corrections to this code citation? Under 2020 NEC 725.48:

So this one is almost certainly code compliant (see Wayne's last post). But I'm unclear if it gives you the twisted pair you need for RS-485? (You need at least one twisted pair, right? That's my experience but I've only used RS-485 in a couple applications.)

Another source

https://www.mouser.com/c/wire-cable/multi-conductor-cables/?number%20of%20conductors=2%20Pair%20Twisted&voltage%20rating=600%20V

...

These do not appear to have NEC recognized ratings and would not be compliant.

 

[hbiss]

These do not appear to have NEC recognized ratings and would not be compliant.

I picked one and the one I looked at does but you are right. It's type CM. Just because it has 600V insulation does not make it suitable for this use. It has to be a cable that can be used at line voltage itself.

-Hal

 

[brycenesbitt]

So this one is almost certainly code compliant (see Wayne's last post). But I'm unclear if it gives you the twisted pair you need for RS-485? (You need at least one twisted pair, right? That's my experience but I've only used RS-485 in a couple applications.) These do not appear to have NEC recognized ratings and would not be compliant.

Three wires are required for RS-485, two of which must be twisted.
The twists are meant to balance out any received noise: they carry a differential signal.
Often four conductor cable is used, with one wire having no purpose:

In the case of optically isolated receivers the cable braid can be used as the ground, but.... it's better to run a dedicated ground then hook the cable braid to ground AT ONE END ONLY.

 

[hbiss]

Three wires are required for RS-485, two of which must be twisted.

1 twisted pair and ground. (Shield= foil, braid, etc.)

-Hal

 

[brycenesbitt]

1 twisted pair and ground. (Shield= foil, braid, etc.)
-Hal

For noise immunity it's best to have the braid/foil separate.
So wires plus minus ground and braid. The braid is connected at only one end. The A B or + - pair must be twisted, the more twists the better. The 18 gauge rule sucks, because that wire can't be twisted as much as 24 gauge.