The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!


2017 NEC and Related
2017 NEC
Now Available!

Recent Posts
Parking lot pole light swap....
by gfretwell
10/24/16 08:46 PM
International Wire Colour Codes
by Tjia1981
10/23/16 12:08 PM
Son of Sparky
by HotLine1
10/20/16 07:43 PM
Speaking of Plugmold ...
by gfretwell
10/17/16 02:37 PM
Broken battery charger? Check for cobwebs!
by gfretwell
10/17/16 02:30 PM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 14
HotLine1 7
ghost307 7
renosteinke 6
Potseal 4
Who's Online
0 registered (), 252 Guests and 5 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#214635 - 12/29/14 03:39 PM NM wire in commercial ceiling?
Trick440 Offline

Registered: 08/15/05
Posts: 248
Loc: Waterford, MI, USA
Can NM wire be used in a commercial building?

We have a suspended ceiling, that is going to be drywalled. Its steel framing and grid.

I just had 2 guys on a job working today and they ran NM for the recessed lighting?! They even fished it down a steel framed wall to the switch.

The Journeymen on site was assuring me its legal, cause its being drywalled and its not a 3 story building?

I have never tried running NM in commercial and never looked it up, but... Looking up 334.12, uses not permitted, (a)(2) says not permitted in, dropped or suspended ceilings.

Please confirm that these guys just wasted more than half a day doing it wrong. smile

Edited by Trick440 (12/29/14 03:42 PM)
Shake n Bake

2014 / 2011 NEC & Related Books and Study Guides
#214636 - 12/29/14 05:04 PM Re: NM wire in commercial ceiling? [Re: Trick440]
shortcircuit Offline

Registered: 06/27/04
Posts: 608
Loc: massachusetts
Depends on the construction type. Section 334.10(3) allows NM in type III, IV an V constructed buildings when concealed with a 15 minute fire rated assembly.

A dropped ceiling that is drywalled is different than a accessible grid type drop ceiling...


ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals