Exposed Romex on ceiling

[Rollie Meyers]

This is just plain wrong. Article 334.15(B) of the 2017 National Electrical Code reads as follows; "Protection from Physical Damage. [NM and NMS] Cable shall be protected from physical damage where necessary by ridgid metal conduit, intermediate metal conduit, electrical metallic tubing, schedule 80 pvc conduit, or other approved means."

You certainly can, and in some circumstances must, put NM cable (romex) in conduit.

The prohibition of NM cable "Romex®" in conduit is a major article in the Urban Legend Code, close to the no splices in electrical panels.

That being said, I don't like NM cable in conduit, but there are times it is necessary.

[Jim Becker]

Rollie, I agree...it's quite common in garages, for example, where the drop the box is surface mounted and the romex disappears into a piece of conduit at ceiling level to get down to the box. My shop building had several of these in it when we acquired the property and I've used the same technique since to add machine outlets. In fact, I'm soon to do it again for the CNC I'm acquiring as I need a four-wire, 30 amp circuit for that application and all my current machine circuits are three-wire.

[Rod Sheridan]

I personally used rubber 10 gage for this (the same stuff I use for machinery cords), but armored would be another option. But that's me...

Hi Jim, I'm curious as to whether that's legal where you live?

Where I live flexible cord is only allowed for portable devices or where motion is required, it cannot be used as a substitute for permanent wiring.........Regards, Rod.

[Jim Becker]

Rod, the heater is "technically" movable in its bracket to re-aim it, etc., so the connection to the J-Box needs to be flexible. I chose rubber coated for that application and I had some left over from a 30-amp machine cord. I guess one could use armored cable (not fun to work with) or a flexible conduit with THHN to accomplish that, too. Honestly, I didn't check on this further...

[Julie Moriarty]

Where I live flexible cord is only allowed for portable devices or where motion is required, it cannot be used as a substitute for permanent wiring.........Regards, Rod.

If you're talking about "cord" as in extension-type cord, no, that use is typically not allowed for permanent electrical connections. I have never seen it allowed anywhere.

Greenfield or Sealtite can be used when connecting to motors or other loads to reduce vibration. In the areas I worked, when hooking up a motor, flexible conduit was required. But there are limitations on length and there may be additional grounding required. For instance if you're using Sealtite to connect a motor and the motor is rated over 20A, a ground wire is required. Usually, the limit on length for any flexible conduit is 6 feet. (All this based on my personal experience working as an electrician in the Chicago area.)