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
Yesterday at 09:52 PM
International Wire Colour Codes
by Texas_Ranger
Yesterday at 08:24 AM
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 12
renosteinke 6
HotLine1 6
ghost307 5
Potseal 4
Who's Online
0 registered (), 242 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#95391 - 09/08/05 06:03 AM Under floor wiring
em3sw Offline
Junior Member

Registered: 01/14/05
Posts: 1
The company I work for manufacturers pre-fab steel shelters for various utilities and recently we had a request I've never dealt with before.....two 240vac 1 phase, AC panels, on exact opposite walls (400amp MB in each), with one feeding the other through feedthru lugs. The customer doesn't want to use the cable tray to get across the room, but rather go through the floor. It's a steel floor, roughly 10" deep (C-channel) and insulated with 1/4" steel plates on top for the finished floor. The run would be apprx. 15' under floor. Originally, we planned on setting PVC in an open channel, before installing the floor,90 degree elbows coming out of the floor below each panel. I say originally because it was going to be 225amps. Now with the 400amp requirement, we're looking at parallel runs of 4/0 and a larger conduit. My question is, can (6) 4/0 wires be bundled up and set to lay loose in the channel in the floor, with either a PVC pipe or wireway coming down from the panels to the 1/4" steel floor for entry into them? (I'd put a wireway adapter or a coupling on the underside of the deck plate to protect the wires as they came up through the floor, we're just trying to avoid an elbow since a 3" pipe would have a rather large radius coming up from the floor if we ran continuous pipe). Sorry for the novel, those still awake, I'd appreciate any suggestions! Thanks!

2014 / 2011 NEC & Related Books and Study Guides
#95392 - 09/18/05 08:45 AM Re: Under floor wiring
tdhorne Offline

Registered: 03/22/01
Posts: 344
Loc: Maryland, USA
Install a listed wireway beneath a removable floor channel cover.
Tom Horne
Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous for general use" Thomas Alva Edison

#95393 - 09/18/05 04:15 PM Re: Under floor wiring
frenchelectrican Offline


Registered: 02/06/03
Posts: 938
Loc: Wi/ Paris France { France for ...
i dont know why not use large " LR and LL " ell for each side so that way it will not produte [ get in ] the interoir wall ..

i done this way before and i used large LL and LR but if you can reach it from " outside " area you can use over sized LB fitting for this

Merci, Marc
Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)


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