Article 645 Information Technology Equipment

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Does anyone know when Article 645 first came into being?? Ive run into to some of these rooms where they got the uninteruppted power sources etc. and their own ac unit to help keep the area cool, but it doesn't appear to wired correctly.

The hvac unit doesn't disconnect power then the epo button is pushed. Nor does the dampers closed for this area (NEC 645.4 2008). This are doesn't seem that old when it was wired.

For fire safety reasons, I would think this wouldve been required for a long time, but Im not certain. Any help would be appreciated.
 

e57

Senior Member
In either '96, or '99 - I think - I'm not sure...

But anyway the wording of it makes it sound like a "requirement" - but the way it has been explained to me is that it is actually conditions to be met if the room is allowed to be used as such... (And trust me it took quite a brow beating here to get me to re-think that.) ;)

Anyway here's an article that touches on the topic....
http://ecmweb.com/nec/code-basics/electric_exploring_requirements_information/
 

e57

Senior Member
I should also mention - the local Fire Department wants the EPO for the UPS anyway... Due to some nasty experiance they had in the past...
 
In either '96, or '99 - I think - I'm not sure...

But anyway the wording of it makes it sound like a "requirement" - but the way it has been explained to me is that it is actually conditions to be met if the room is allowed to be used as such... (And trust me it took quite a brow beating here to get me to re-think that.) ;)

Anyway here's an article that touches on the topic....
http://ecmweb.com/nec/code-basics/electric_exploring_requirements_information/

Its my understanding that since the room is 'used' as such, then they must comply with all the requirements of 645.
 

iwire

Moderator
Staff member
Location
Massachusetts
Its my understanding that since the room is 'used' as such, then they must comply with all the requirements of 645.

No, that is a common misconception.

The NEC does not require us to use 645 at all, we can choose to use it and by doing so it allows us some latitude in wiring methods
 

DataCenterGuy

Member
Location
New York
Right. 645 is optional. If you declare it an Article 645 ITE (Information Technology Equipment) Room (the NEC terminology for what we commonly call a Data Center, Computer Room or Server Room), you can use unsecured Power Whips under the raised floor (something IT people almost always want for "flexibility") and you can use PVC Cable under the floor rather than Plenum Rated Cable (a small cost advantage). But to do this you must meet ALL the requirements of 645, which includes the hated EPO (Emergency Power Off) Switch by every door, which scares most IT people to death because so many have been pushed in error or maliciously, downing the entire data center. APC, as an example, makes a whole marketing case on using their overhead wiring system to provide "flexibility" while avoiding Article 645 and the EPO. 645 existed in 1993 (I don't have books older than that), but only recently have inspectors seemed to be aware of it, so there are many, many rooms built in recent years that violate it in lots of ways.
 

wireguru

Senior Member
Right. 645 is optional. If you declare it an Article 645 ITE (Information Technology Equipment) Room (the NEC terminology for what we commonly call a Data Center, Computer Room or Server Room), you can use unsecured Power Whips under the raised floor (something IT people almost always want for "flexibility") and you can use PVC Cable under the floor rather than Plenum Rated Cable (a small cost advantage). But to do this you must meet ALL the requirements of 645, which includes the hated EPO (Emergency Power Off) Switch by every door, which scares most IT people to death because so many have been pushed in error or maliciously, downing the entire data center. APC, as an example, makes a whole marketing case on using their overhead wiring system to provide "flexibility" while avoiding Article 645 and the EPO. 645 existed in 1993 (I don't have books older than that), but only recently have inspectors seemed to be aware of it, so there are many, many rooms built in recent years that violate it in lots of ways.

yep. much better to leave the underfloor space for air, and use overhead cable trays for wiring.
 
Right. 645 is optional. If you declare it an Article 645 ITE (Information Technology Equipment) Room (the NEC terminology for what we commonly call a Data Center, Computer Room or Server Room), you can use unsecured Power Whips under the raised floor (something IT people almost always want for "flexibility") and you can use PVC Cable under the floor rather than Plenum Rated Cable (a small cost advantage). But to do this you must meet ALL the requirements of 645, which includes the hated EPO (Emergency Power Off) Switch by every door, which scares most IT people to death because so many have been pushed in error or maliciously, downing the entire data center. APC, as an example, makes a whole marketing case on using their overhead wiring system to provide "flexibility" while avoiding Article 645 and the EPO. 645 existed in 1993 (I don't have books older than that), but only recently have inspectors seemed to be aware of it, so there are many, many rooms built in recent years that violate it in lots of ways.

This room doesnt have any wires under a floor. its all on a rack with cables ran and from a cable tray. I still think the 645 applies for them to use the advantages there.
 

iwire

Moderator
Staff member
Location
Massachusetts
This room doesnt have any wires under a floor. its all on a rack with cables ran and from a cable tray. I still think the 645 applies for them to use the advantages there.

Given the fact all cables are above the floor they do not have to use 645.
 
Let me ask you this.

What characteristic of this space leads you to think 645 must be used?

Well, for one, they are using cords as fixed wiring of a structure, violating 400.8. IMO. Not to mention NFPA 75 concerning definition of IT rooms.

It appears they are trying to use the 'flexibility' of article 645, but do not want to adhere to all the stipulations. If they are not going to do that, then ALL the rest of the NEC will apply to these wiring methods.

Why install a EPO, if they are not going to wire it correctly??
 
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