ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
Canada for the win
by gfretwell - 12/06/22 08:28 PM
Tiny Homes and the NEC
by gfretwell - 12/06/22 01:43 AM
EMC Glands on Motors
by Trumpy - 12/01/22 06:12 AM
Ground Rods: Installation and Hook-Up
by Trumpy - 12/01/22 05:54 AM
Happy Thanksgiving all!
by gfretwell - 11/30/22 05:55 PM
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
0 members (), 36 guests, and 12 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
#170435 11/02/07 08:22 PM
Joined: May 2001
Posts: 376
F
frank Offline OP
Member
Can 12/4 be ran from three phase panels for normal and standard emergency recepticals in a computer room?
thanks

Joined: Oct 2007
Posts: 56
S
Member
What exactly are "normal and standard emergency receptacles"? And I don't think I've seen any reference to computer rooms in the code book.


Shawn.

Joined: Dec 2006
Posts: 33
W
Member
Are you referring to two different sources ( normal from hydro and standby, from say a UPS or a genset) inside a common piece of cable such as 12/4 bx cable?

Joined: May 2001
Posts: 376
F
frank Offline OP
Member
It's a hospital so the equipment is on both generator and UPS.Would 12/4 or any 4 conductor ac90 be legal on general purpose recepticals from 3 phase panels.I have only used it for 3 phase 4 wire equipment not plugs.I'm thinking the neutral could possibly end up being to small.The 12/4 comes from the panel to a j-box where they split into circiuts.Not the way i would do it but if it passes so be it.
thanks

Joined: Dec 2006
Posts: 33
W
Member
What you have is an emergency panel feeding a UPS that feeds to outlet in a server room??? Three hots and a neutral for plugs. I don't think it is illegal as per the Canadian Electrical Code to do that unless the circuits are in a intermediate and critical care area (24-110) That said, any recent wiring I have seen done in healthcare facilities all seem to use a hot and a dedicated common labelled as such for each hot. (two wire circuits)

Joined: Jul 2005
Posts: 183
J
Member
You can do it, but with harmonic producing loads such as that found in computer rooms, you are better off with a separate neutral for each circuit. Certain harmonics can load up the neutral beyond the ampacity of a single circuit.


Link Copied to Clipboard
Featured:

Tools for Electricians
Tools for Electricians
 

* * * * * * *
2023 National Electrical Code (NEC)
2023 NEC Now Available!
 
* * * * * * *

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

 

Member Spotlight
JoeKP
JoeKP
Berkley, MA
Posts: 144
Joined: March 2008
Top Posters(30 Days)
Trumpy 6
NORCAL 3
Popular Topics(Views)
300,608 Are you busy
230,284 Re: Forum
215,066 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.5