ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
May I backfeed 3 phase transformer?
by dsk - 10/22/21 04:37 AM
Wire sizing
by gfretwell - 10/21/21 10:12 PM
GFCI's pops in large numbers
by dsk - 10/21/21 02:03 AM
Need some info on Japanese outlets, 200V 15A
by andey - 10/20/21 08:05 AM
nec 110.3 (B)
by watersparkfalls - 10/19/21 07:09 AM
New in the Gallery:
240/208 to a house
240/208 to a house
by wa2ise, October 9
Now you know.
Now you know.
by Tom_Horne, September 7
Who's Online Now
1 members (HotLine1), 5 guests, and 18 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 3 1 2 3
#191397 12/27/09 01:29 AM
Joined: Aug 2007
Posts: 853
L
leland Offline OP
Member
Brain block and too lazy to look right now (sorry).
Now I know NM is not rated for 'WET' location,but ok for Damp.
I also understand anything in conduit under ground is 'wet'.

So to the point: IF I run NM across an open ceiling (not allowed above a drop ceiling),poke thru the out side wall with PVC,LB down into a bell box with a WR GFCI and an 'in use' cover.

Is that cool? Commercial application.

2017 / 2014 NEC & Related Books and Study Guides
leland #191398 12/27/09 01:43 AM
Joined: Aug 2001
Posts: 459
J
Member
Most seem to consider NM into the back of a disco or box ok. Running it thru a LB is not ok. You would need to switch wiring methods at the plane of the wall.

Jim M #191399 12/27/09 01:45 AM
Joined: Aug 2007
Posts: 853
L
leland Offline OP
Member
So if I install a change over connector,is that good?

leland #191400 12/27/09 02:11 AM
Joined: Jul 2004
Posts: 9,668
Likes: 6
G
Member
Why not just use UF?


Greg Fretwell
gfretwell #191402 12/27/09 03:03 AM
Joined: Aug 2007
Posts: 853
L
leland Offline OP
Member
mechanical protection Greg.

Install-
Straight from panel to outside wall location.With NM, all interior.
Now I drill a 1" hole from out side in,sleeve a piece of 1/2 pvc,inside out/mount an LB and drop down to the WP box.
The NM just slides in the conduit,thru the LB and terminates on the WR GFCI rec.

IMO,the conduit is a sleeve. BUT... Is it a wet location?

leland #191404 12/27/09 04:01 AM
Joined: Jul 2004
Posts: 9,668
Likes: 6
G
Member
It is certainly a wet location but UF will go anywhere NM will go plus being OK "wet". (run in in your RNC sleeve) If PP is important, pipe it all the way and use THWN.


Greg Fretwell
leland #191429 12/29/09 02:36 AM
Joined: Aug 2006
Posts: 356
Member
334.10(A)(1) states that the NM cable can be installed in NORMALLY DRY location. woudn't you agree that the interior of LB is NORMALLY DRY location? depending on the location, i can't think of any immediate time that i have opened a LB cover and it was wet inside.

Besides i think sometimes it is O.K. to not follow the code verbatim, and make some exception, because I know from experience that it will be a safe installation. just like leland's installation.
Of course it all depends on the AHJ.


Be kind to your neighbor, he knows where you live

Niko #191432 12/29/09 04:33 AM
Joined: Jul 2004
Posts: 9,668
Likes: 6
G
Member
I suppose the AHJ makes the rules but article 100 says wet locations are "... unprotected locations exposed to weather".
In 2008 they also removed the confusion about above grade wet location raceways
Quote
300.9 Raceways in Wet Locations Above Grade.
Where raceways are installed in wet locations above grade, the interior of these raceways shall be considered to be a wet location. Insulated conductors and cables installed in raceways in wet locations above grade shall comply with 310.8(C).




Greg Fretwell
gfretwell #191436 12/29/09 10:28 AM
Joined: Apr 2002
Posts: 7,283
Likes: 3
Member
Le:
Your proposed install would get another 'nay' from me.


John
HotLine1 #191437 12/29/09 11:59 AM
Joined: Jan 2005
Posts: 5,316
Cat Servant
Member
Please note that the latest code edition goes so far as to ban the use of ordinary NM in even damp locations. On another forum, home inspectors are even being urged to call out crawl space NM runs as being contrary to the NEC.

I don't say I agree with this - but that's the way the code reads. First they tell you that NM allowed in damp locations ... then a few paragraphs later tell you that NM-B, the stuff we actually use, can't go into even damp areas.

The law has a principle of not entertaining petty claims. It frowns upon $1 lawsuits and 1mph speeding tickets, for example. There's even a fancy latin name for this principle.
What I'm getting at is that I would not fault an installation that had a transition to a 'proper' wiring method as soon as possible, after entering a different environment.

NM ("Romex") is an amazing material. First they expand its' use, pointing to 70+ years of use as proof that it is safe. Then they tell us we can't put it in the one place where most of it goes (crawl spaces) and require us to use AFCI's to protect it. They tell manufacturers they have to use 'wet location' conductors (Thhn/Thwn) then tell us it can't even be in damp locations.

I can't speak for anyone else, but I'm confused!

Page 1 of 3 1 2 3

Link Copied to Clipboard
Featured:

Tools for Electricians
Tools for Electricians
 

* * * * * * *

2020 Master Electrician Exam Preparation Combos
2020 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
lil suzi
lil suzi
Midwest
Posts: 57
Joined: August 2003
Top Posters(30 Days)
dsk 7
Popular Topics(Views)
284,812 Are you busy
217,381 Re: Forum
203,722 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.5