Inspecter 507 and others, a wiring question

[GaryM]

It's my understanding, perhaps incorrect, that you are NOT supposed to run Romex inside of EMT. It's also my understanding that you are not allowed to strip the individual wires out of Romex and use those inside the EMT. You are supposed to use THHN, I think, wire. The wires inside the Romex sheath are not THHN wires, right.

The case is where you are running Romex up in the rafters, then coming down a concrete wall to a metal box. If I remember correctly you need a box in the rafters to transition from Romex to the THHN wire and the EMT. Then the EMT running across the hard surface wall to the surface mounted box.

Am I correct? That's what I remember being told in the past. But of course I might be misremembering, or been told worg!

[Stoneheartfarm]

I've always dropped ordinary romex down them. I guess I thought THHN was primarily for service entrances.

Steve

[GaryM]

I was told at the time, and this was a while back, that Romex was not to be used in EMT because of space issues. For example there's a chart that says you can run this many #12 or #14 etc in 1/2" EMT. But if the chart says for example, 6 #12 wires, I don't think you could run 3 runs of 12-2 in the same EMT.

I'm eager to learn though!

[Inspector507]

GaryM,
The correct way to install it, around here, is run your Type NM cable (Romex is a brand name) through the attic/joist space. Sleeve it down the wall with PVC or EMT with fittings and bushings on each end. Stop the pipe about an inch short of the box location, then mount the box with a cable connector in it.
The conductors inside of NM cable (fairly new cable) are THHN, but is not marked or identified with any markings, even though I KNOW it's THHN. Thats why we do not accept you stripping the cable jacket off and run it inside the pipe.
I have seen it done so many different ways in other areas, but this is acceptable here.

The space requirements DO come into play if you are sleeving NM cable in EMT. In your example of 6 #12 wires and 3 12/2 NM cables, you have to measure the diamter of the whole cable and chart it from there, not the individual wires.

[GaryM]

OK, I guess I was told wrong years back. My method works and is OK, but not required. I was at my BIL's tonight to make his connections.

We had two runs of 12-2 with ground in the EMT. I did use some short pieces of stripped out wire from the NM cable, yeah I know Romex is a brand but if you're not in the trade it's kind of like using Kleenex instead of tissue, to make connections between the receptacles and the switch.

Everything works.

Thanks for the clarification.

[Inspector507]

<font color="blue"> My method works and is OK, but not required. </font color>

Yep, that will work.......... [img]/forums/images/icons/grin.gif[/img]