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#170435 - 11/02/07 06:22 PM 12/4 in computer rooms
frank Offline
Member

Registered: 05/29/01
Posts: 373
Loc: windsor ontario canada
Can 12/4 be ran from three phase panels for normal and standard emergency recepticals in a computer room?
thanks

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#170440 - 11/02/07 07:50 PM Re: 12/4 in computer rooms [Re: frank]
SP4RX Offline
Member

Registered: 10/01/07
Posts: 56
Loc: Edmonton, Alberta, Canada...eh
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.

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#170441 - 11/02/07 08:22 PM Re: 12/4 in computer rooms [Re: SP4RX]
wacked Offline
Member

Registered: 12/19/06
Posts: 33
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?

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#170471 - 11/03/07 05:52 PM Re: 12/4 in computer rooms [Re: wacked]
frank Offline
Member

Registered: 05/29/01
Posts: 373
Loc: windsor ontario canada
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

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#170517 - 11/04/07 09:06 PM Re: 12/4 in computer rooms [Re: frank]
wacked Offline
Member

Registered: 12/19/06
Posts: 33
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)

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#170536 - 11/05/07 09:31 AM Re: 12/4 in computer rooms [Re: frank]
jay8 Offline
Member

Registered: 07/28/05
Posts: 183
Loc: Vancouver, BC
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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