T-Stat Wire with 14/2 in Same Conduit for 18"

[Spudland_Dave]

Getting ready to install power to my Hot Dawg....ASTHETICALLY, I'd love to run my T-Stat wire...which is this exact wire:

http://www.southwire.com/ProductCatalog/XTEInterfaceServlet?contentKey=prodcatsheet240

..14/2 home run from the panel into the heater...Just 18" Of ENT Conduit on the interior of the shop from the ceiling to the heater itself. In researching it, I'm getting confused...my T-Stat wire is rated for 150v, SOME links I've read state is the T-Stat wire is rated for more then the line voltage, its ok...some say its not ok at all, under any circumstances.

Some justifications provided that I read (I'm no sparky, so don't shoot me for saying it)...because the 14/2 is Romex and sheathed...its essentially its own raceway...Running the T-Stat in a conduit with THHN would be a no-go, but T-Stat Wire + 14/2 Romex in a conduit is OK as long as it does not max out the fill %.

 

[sberry]

To the heater run it, the worst thing would be some interference, I doubt its an issue.

 

[rlitman]

The thermostat wire needs an insulation rating higher than the 120V the Hot Dawg uses since it is in the same enclosure as the line voltage anyway once it enters the heater. 150V thermostat wire, and you're GTG.

 

[Slowgsr]

Unless the tstat wire is also 120v which I doubt it is then absolutely not! You cannot run wires of different voltages in the same conduit/raceway.

 

[sberry]

Service entrance has different voltage in the same cable. ha

 

[rlitman]

Service entrance has different voltage in the same cable. ha

Lots of things do. I've got a number of Form 9s meter pans here. The metering cable (I think it is 10 wires from memory), has 480V on some wires, and CT connections carrying millivolts on others.

 

[n8n]

standard practice would be to zip tie thermo wire to outside of ENT

 

[EdT]

Insulating and voltage requirements aside, it's generally better to separate power wires from signal wires if possible. Sometimes the power leads can induce a signal in the control wires and cause problems. It depends a lot on the control system. If it's a simple electromechanical control there should be no problems since they are pretty immune to this kind of thing. If the control is "electronic" or "digital" has any blinky lights, LCD display or LED display then it's probably more sensitive and there could be a problem. If you find it aesthetically more appealing to run the control wire inside the conduit with the power wire, go ahead and do it. If there's a problem it doesn't sound like it would be hard to retrofit the ugly solution.

 

[rockwithjason]

Unless the tstat wire is also 120v which I doubt it is then absolutely not! You cannot run wires of different voltages in the same conduit/raceway.

that is patently false. you can run any voltage level together in conduit and the code doesn't care. What the code does care about is that the voltage ratings of the wires are the same. you could use tstat wire if the voltage rating is the same as the other wires in the conduit. some jurisdictions will cut you a break and allow you to run it with the feed wires but it's not technically kosher. most tie the tstat cable on the outside of the conduit as stated before.

 

[LS6 Tommy]

Not saying it's code, but we were always taught you can't run line and control wires together in the same conduit...

Tommy

 

[alfredeneuman]

Yes, you can run it in the same conduit.

Class1 low voltage conductors (which is what you have) can be run in the same conduit if it's running the same equipment.

Class2&3 are Limited Power Circuits, and not allowed with the power conductors.

Double check the voltage limit on the cable just to be safe

 

[LS6 Tommy]

Yes, you can run it in the same conduit.

Class1 low voltage conductors (which is what you have) can be run in the same conduit if it's running the same equipment.

Class2&3 are Limited Power Circuits, and not allowed with the power conductors.

Double check the voltage limit on the cable just to be safe

Thanks for the clarification!

Tommy