EPO in Data Centers, is it really needed???

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faresos

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Hello All,

Is an EPO system required for data centers? we have an existing building with three spaces designated as data centers that has already an EPO system to kill the power for electronic equipment and HVAC system serving this space. The UPS's (4)750KVA modules are located remotely but the PDU's and the remote power panels are located within data center space. The owner wants to remove the EPO system completely as he has a concern that it will cause more problem than providing any benefits, He is asking if there is any applicable code that will force us to keep the EPO system and prevent us from removing it? My thinking the NEC (Art. 645) doesn't require to have it but it tells you the requirement if you need to provide it.

Thanks,
 
faresos said:
Hello All,

Is an EPO system required for data centers? we have an existing building with three spaces designated as data centers that has already an EPO system to kill the power for electronic equipment and HVAC system serving this space. The UPS's (4)750KVA modules are located remotely but the PDU's and the remote power panels are located within data center space. The owner wants to remove the EPO system completely as he has a concern that it will cause more problem than providing any benefits, He is asking if there is any applicable code that will force us to keep the EPO system and prevent us from removing it? My thinking the NEC (Art. 645) doesn't require to have it but it tells you the requirement if you need to provide it.

Thanks,
Click to expand...
If you want my opinion NEC doesn't define what art 645 applies to very well.

My single computer sitting on my desk in my office could possibly fall under 645. Now maybe 645 takes it one step further - I may need to put same computer in a room which the main purpose of the room is to house that computer, then I may have an art 645 application. :roll:

BTW my computer sitting on my desk in my office is a fairly simple notebook computer - not the most basic, not the most advanced either though.

645 doesn't really give us any limitations on equipment details necessary before 645 rules kick in. Equipment with information technology capabilities exist everywhere these days as well. Does that mean every room in any occupancy is potentially a 645 application? Without clarification I think we are moving closer to that all the time.
 
faresos said:
Hello All,

Is an EPO system required for data centers? we have an existing building with three spaces designated as data centers that has already an EPO system to kill the power for electronic equipment and HVAC system serving this space. The UPS's (4)750KVA modules are located remotely but the PDU's and the remote power panels are located within data center space. The owner wants to remove the EPO system completely as he has a concern that it will cause more problem than providing any benefits, He is asking if there is any applicable code that will force us to keep the EPO system and prevent us from removing it? My thinking the NEC (Art. 645) doesn't require to have it but it tells you the requirement if you need to provide it.

Thanks,
Click to expand...

645 allows you to do wiring and place cables in locations that are not allowed under the general rules of the NEC. 645 also requires you to do several things (remote disconnect controls, for instance) to provide a balance to the increased "hazard" of these lessened requirements.

You need not use the methods allowed under 645, then it is just a normal space and you are not required to do the special things.

It's an engineering balance.
 
fmtjfw said:
645 allows you to do wiring and place cables in locations that are not allowed under the general rules of the NEC. 645 also requires you to do several things (remote disconnect controls, for instance) to provide a balance to the increased "hazard" of these lessened requirements.

You need not use the methods allowed under 645, then it is just a normal space and you are not required to do the special things.

It's an engineering balance.
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Makes sense. I never use 645 so am not all that familiar with it's application.

Based on that I'd also say - and to help with OP's question - if you take advantage of what 645 allows you to do, then you must follow up with other requirements of 645 like the questioned disconnecting means, otherwise treat it like any other chapter 1-4 application and the disconnecting means wouldn't be required.
 
In short article 645 is opitional.

If you choose to use the leniency allowed by 645 than you also must have EPOs, smoke dampers etc.

Best bet is to forget 645 exists and wire the space as a normal space.
 
Thanks all for the reply...

From reading the replies above, I have concluded the following; since the existing space has a raised floor (which also used for air handling through the CRAC's, plenum space) and has used under floor flexible power whips from the the Remote power panels to the server racks (which means took advantage of Art. 645) then we have to have the EPO system. For some reason I thought we don't need it all and it's an optional but if we need to install it then it needs to be done per 645 requirement.
 
iwire said:
In short article 645 is optional.
If you choose to use the leniency allowed by 645 than you also must have EPOs, smoke dampers etc.
Best bet is to forget 645 exists and wire the space as a normal space.
Click to expand...

First, I agree with iwire's position as a default in this situation.

faresos said:
Thanks all for the reply...
From reading the replies above, I have concluded the following; since the existing space has a raised floor (which also used for air handling through the CRAC's, plenum space) and has used under floor flexible power whips from the the Remote power panels to the server racks (which means took advantage of Art. 645) then we have to have the EPO system. For some reason I thought we don't need it all and it's an optional but if we need to install it then it needs to be done per 645 requirement.
Click to expand...

Raised Floor and flexible wiring does not necessarily take advantages of leniencies in 645. If the space complies with 300.22(C), then you are ok for those items. 645 offers relaxed rules as compared to the mandatory articles in the NEC, but if you choose to use the leniencies, you have to provide other reliability killing items such as EPO.
 
faresos said:
Hello All,

Is an EPO system required for data centers? we have an existing building with three spaces designated as data centers that has already an EPO system to kill the power for electronic equipment and HVAC system serving this space. The UPS's (4)750KVA modules are located remotely but the PDU's and the remote power panels are located within data center space. The owner wants to remove the EPO system completely as he has a concern that it will cause more problem than providing any benefits, He is asking if there is any applicable code that will force us to keep the EPO system and prevent us from removing it? My thinking the NEC (Art. 645) doesn't require to have it but it tells you the requirement if you need to provide it.

Thanks,
Click to expand...
Obviously I'm not in a position to comment on NEC requirements. So I won't.
I dealt with a few data centres here in UK. They have all had UPS systems supplying them. And an EPO system to kill those - in the event of an emergency. Maybe a fire or something like that. You wouldn't want the servers continue chuntering merrily in such circumstances.
Just a passing thought.
 
Forgot one more thing, I just need to make sure that there are no other codes such as Fire Protection Code will require us to use the EPO system in Data Centers. Also, to make sure I understand it correctly, in order that a data center to be exempt from an EPO button requirement then it must meet these criteria : the absence of cables underneath a raised floor and not disclosing that you're following NFPA 75.

Thanks in advance for your help
 
faresos said:
Also, to make sure I understand it correctly, in order that a data center to be exempt from an EPO button requirement then it must meet these criteria : the absence of cables underneath a raised floor and not disclosing that you're following NFPA 75.
Click to expand...

A code official can only require you to follow NFPA 75 if it has been adopted as a referenced standard by a code or is brought in as a code itself. I know of no such jurisdiction in the US.

Cables are permitted below a raised floor without EPO as long as they are compliant with the regular articles of the code, such as 300.22(C) or 800 or 801 etc.

645 is optional if you want to use the leniencies shown in 645.
 
faresos said:
Forgot one more thing, I just need to make sure that there are no other codes such as Fire Protection Code will require us to use the EPO system in Data Centers. Also, to make sure I understand it correctly, in order that a data center to be exempt from an EPO button requirement then it must meet these criteria : the absence of cables underneath a raised floor and not disclosing that you're following NFPA 75.

Thanks in advance for your help
Click to expand...
Though you bring up some points that may make 645 kick in, the basic rule is in 645.4.

This article shall be permitted to provide alternate wiring methods to the provisions of Chapter 3 and Article 708 for power wiring, Parts I and III of Article 725 for signaling wiring, and Parts I and V of Article 770 for optical fiber cabling where all of the following conditions are met:
Click to expand...
If you don't use any of the alternate methods permitted in 645, you revert back to chapter 3, art 708, 725, and 770. Having the raised floor may be pointless if you don't use alternate methods permitted in 645, but you either comply with all of 645 or you don't use 645 at all, you don't mix and match where it is convenient for you.
 
I think that one of the items that drives the optional nature of the article is the very loose definition of information technology room.

When you look at the UL general directories definition of information technology equipment you quickly see it covers a very wide array of equipment, from servers to pencil sharpeners, from computers to phone answering machines, from UPSs to copy machines.

My point is that almost any business has these items in many rooms that we would never treat as a 645 room.

645 does not tell us at what square footage, or quantity of equipment, or what VA load, or what the use of equipment requires us to use 645. It is just an option, one that in my opinion is a poor one.

EPOs are much more likely to cause an unwanted outage than save any property and one of the requirements of a 645 room is limited access making it less user friendly.
 
I think the definition of an information technology room is irrelevant to the use (or not) of 645 . It looks different to different people.

For a small office it might look like a coat closet with an IT rack and a shared AHU, or it might look like thousands and hundreds of thousands of sq-ft with IT racks. 645 just offers you some leniencies to the rest of the code if you want it. The pre-requisites in 645 are a big deterrent.

I use a raised floor to transport chilled water piping, air and power ..... no 645. Just follow the rest of the code as if it is a office building and the space below the raised floor is the space above a suspended ceiling and the raised floor is 300.22(C).
 
ron said:
I think the definition of an information technology room is irrelevant to the use (or not) of 645 . It looks different to different people.
Click to expand...

I think we are saying pretty much the same thing.

If the article was mandatory the definition would have to be much more definitive to be enforceable.
 
Just got another question with regards of the EPO system, can we place the EPO sytem inactive when necessary?
 
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