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#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.


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