IT Equipment in non-IT environment

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smccluer

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Situation: We are installing a data center. The equipment is a single system consisting of a couple cabinets of UPS and 14 equipment racks. Type SO interconnect cables between adjacent cabinets are run in troughs above the equipment that are part of each cabinet. Where necessary to cross aisles, cables are supported by overhead ladder rack. All equipment is provided by a single vendor, installed in accordance with the vendor's requirements, and listed under a single UL file per UL Std 60950 for IT equipment. The listing includes the UPS, cabinets, interconnect cables, and ladder racks.

The room meets all but one of the requirements of NEC Article 645 for IT environments, therefore fails to be Article 645-compliant.

The inspector claims that because the room is not Article 645-compliant, the equipment no longer qualifies under the exemptions allowed by 645. He has tagged the system because the interconnect cable are now considered premises wiring, and the NEC prohibits use of SO cord for permanent installations. He has demanded that all the interconnect cables be removed and replaced with either Type MC or TC cable or be run in conduit.

The vendor claims that the listing is for the equipment, not for the room. Per Article 90.7, "The factory-installed internal wiring or the construction of equipjment need not be inpected at the time of installation of the equipment, except to detect alterations or damage, if the equipment has been listed by a qualified electrical testing laboratory."

Question: I have searched through NFPA 70 and NFPA 75, and I can not find where it states that the UL listing for IT equipment is VOID if it is not installed in a room that complies with Article 645. Who is right?
 
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earlydean

Senior Member
Re: IT Equipment in non-IT environment

In the UL white book, under NWGQ, INSTALLATION:
"Some equipment has been evaluated for installation......Such equipment is provided with a marking..."To be installed only in a Restricted Access Location" or similiar wording"

I would get me a copy of the White Book.

Earl
 
ron

ron

Senior Member
Location
New York, 40.7514,-73.9925
Re: IT Equipment in non-IT environment

smccluer,
You've got a tough road ahead of you with this AHJ. UL lists many different types of IT equipment under their IT equipment standard, but does not necessarily mean that it is one assembly and tested as one assembly.
Typically I've found that if you will need the leniencies provided by Article 645, even if you use UL Listed IT equipment, it is still a different method than permitted by the first 4 chapters of the code, Hence requiring compliance with all aspects of 645.2 et al.
Good luck, you have a good point, but I'm not sure it will be concrete enough to convince an AHJ or his/her supervisors.

By the way, the environment being IT or non-IT doesn't matter, it is whether you need those 645 leniencies which determine whether you must conform to 645.2

[ October 09, 2003, 11:37 PM: Message edited by: ron ]
 
dereckbc

dereckbc

Moderator
Staff member
Location
Plano, TX
Re: IT Equipment in non-IT environment

smccluer,

I concur with Ron. I design data centers and have been in the same situation. You realistically probably only have two options open to you.

1. Upgrade the site to meet the requirements of 645.

2. Use tray cable or other approved wiring methods.

Good Luck

Dereck
 
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