EPO Question

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ed downey

Senior Member
Location
Missouri
I have an owner that has a large Data Center that is a co-location facility (multiple tenants lease the space in a Data Center). Some of the tenants are concerned about the EPO button being accessible to other people in that come in to work on their equipment.

I am trying to think of any way that an AHJ would allow a change to this and wanted to know if anyone has had any luck in the location of the EPO.

My idea is to install and EPO in the Main Security Office (Manned 24 hours a day) that basically has the has the functionality of the EPO for each computer room.

You could also make the EPO buttons in the Computer room only operational after a fire alarm event in the area has happened.

Looking for any thoughts on the above before I present it to the local AHJ.

645.10 Disconnecting Means A means shall be provided to disconnect power to all electronic equipment in the information technology room. There shall also be a similar means to disconnect the power to all dedicated HVAC systems serving the room and cause all required fire/smoke dampers to close. The control for these disconnecting means shall be grouped and identified and shall be readily accessible at the principal exit doors. A single means to control both the electronic equipment and HVAC systems shall be permitted. Where a pushbutton is used as a means to disconnect power, pushing the button in shall disconnect the power.
Thanks,
 

chris kennedy

Senior Member
Location
Miami Fla.
Occupation
60 yr old tool twisting electrician
I have an owner that has a large Data Center that is a co-location facility (multiple tenants lease the space in a Data Center). Some of the tenants are concerned about the EPO button being accessible to other people in that come in to work on their equipment.

Anyone working in that room needs to have access to the EPO.



My idea is to install and EPO in the Main Security Office (Manned 24 hours a day) that basically has the has the functionality of the EPO for each computer room.
What does this mean?

You could also make the EPO buttons in the Computer room only operational after a fire alarm event in the area has happened.
An individual is working in this room when the UPS starts smoking. He/she runs out the door and hits the EPO on the way out, nothing happens. 30 seconds later F/A is actuated by the smoke and the EPO is operational. Oops, no one in the room to hit the button!

Looking for any thoughts on the above before I present it to the local AHJ.
I think you will be hard pressed to sell this to any AHJ, good luck, let us know if it flies.
 

jumper

Senior Member
I agree with Chris. I do not think this will fly. We have EPOs, in a variety of places including data centers, and the big red button must be accessible at each door.

Is there a chance that someone will hit it or lean up against it on accident, yes, been there, done that, oh well.

Lives are important than data and temporary shut downs.
 

chris kennedy

Senior Member
Location
Miami Fla.
Occupation
60 yr old tool twisting electrician
Is there a chance that someone will hit it or lean up against it on accident, yes, been there, done that, oh well.

Glass break or shroud protected OPO's will eliminate the bump/shutdown scenario and still meet the requirements of 645.10.
 

cadpoint

Senior Member
Location
Durham, NC
Why not turn the panic button into a fire alarm pull station where a glass rod needs to be broken ? IE to be activitaved! (sp)
 

benaround

Senior Member
Location
Arizona
The rule does not say that the epo has to be uncovered, and prone to accidently getting

bumped off, imo. What do you guys think of a 'clear' hinged box of some sort over the epo

that could be easily tapped down to allow use of the epo.
 

Volta

Senior Member
Location
Columbus, Ohio
The rule does not say that the epo has to be uncovered, and prone to accidently getting

bumped off, imo. What do you guys think of a 'clear' hinged box of some sort over the epo

that could be easily tapped down to allow use of the epo.

I think it's a good idea. You can get them with sounders inside so there is a local audible alarm that would get people's attention before the EPO has been actuated.

Commonly used to reduce prank fire alarm pull station activity.
 

e57

Senior Member
I think it's a good idea. You can get them with sounders inside so there is a local audible alarm that would get people's attention before the EPO has been actuated.

Commonly used to reduce prank fire alarm pull station activity.
I like it! It should also take a series of pictures - if not for evidence - just for fun...
 

DataCenterGuy

Member
Location
New York
If this room is taking advantage of features or options that require it to be an Article 645 Room, then disconnecting the EPO's and re-wiring per Chapter 3 is not an option. 645.10 refers only to "Approved Disconnecting Means", but I have never heard of anything but a Pushbutton being used. And it clearly states that it must be "readily accessible at the principal exit doors". No ambiguity here. Take a look at the STI (Safety Technology International, Inc.) Covered Buttons. They can be provided with an integral Horn that sounds if the cover is lifted. But the "Break Glass" button may be a problem. 645.10 refers to a "pushbutton", and I have been told (though I don't know where it might say it) that the common "Break Glass" button does NOT qualify as an Approved Disconnecting Means for an EPO because it Releases the plunger when the glass is broken and is, therefore, not a "Pushbutton". Can anyone confirm that?
 

Volta

Senior Member
Location
Columbus, Ohio
If this room is taking advantage of features of options that require it to be an Article 645 Room, then disconnecting the EPO's and re-wiring per Chapter 3 is not an option.
Sure it is. If the rooms were rewired to Ch. 3, they would not be taking advantage or the features or options allowed under Article 645, thus the EPO would not be required. I'm not claiming that is a good solution, just that it is one.

Chicken or egg? ;)
645.10 refers only to "Approved Disconnecting Means", but I have never heard of anything but a Pushbutton being used. And it clearly states that it must be "readily accessible at the principal exit doors". No ambiguity here. Take a look at the STI (Safety Technology International, Inc.) Covered Buttons. They can be provided with an integral Horn that sounds if the cover is lifted. But the "Break Glass" button may be a problem. 645.10 refers to a "pushbutton", and I have been told (though I don't know where it might say it) that the common "Break Glass" button does NOT qualify as an Approved Disconnecting Means for an EPO because it Releases the plunger when the glass is broken and is, therefore, not a "Pushbutton". Can anyone confirm that?

Other than a pushbutton can be installed. Any means must be approved by the AHJ as shown in the first sentance of 645.10. The second to last offers a pushbutton as a method, and specifies how it shall act where used.

NEC would allow a pull station, or a "Break Glass", IMO, if ok with the AHJ. The ADA specifications may preclude the use of devices that must be grasped, however. But I feel that any of those methods meets the intent and letter of 645.4(1).
 

iwire

Moderator
Staff member
Location
Massachusetts
Ed, there is no reason to have an EPO at all if you were to wire the room using only Chapter 3 wiring methods and do not use the leniences given by 645.
 

jap

Senior Member
Occupation
Electrician
It always interested me that these are indicated to be placed near the exit doors as if the people inside would take the time to Power the units off is something went wrong.

If the UPS Unit catches on fire, I dont think most would spend the time to stop and hit the EPO Button or break the glass and push a button on the way out,,,, They'd probably just run out and let the Firemen hit it on the way in.
:)
 

James13

Member
You need an EPO in the exit of each computer room by code, not the front desk. I assume you are going to shunt trip the circuit breaker via a contactor feeding the hvac unit, UPS and fire damper (NO contact)
 

ed downey

Senior Member
Location
Missouri
Unfortunately the room is already wired to Article 645.

I was just looking for a way to help the owner more easily lease space inside the Data Center. The rooms are ~40,000 SF each and he has had potential occupants ask if the EPO could be moved or disabled.

I told him no the EPO could not be disabled as he would be opening himself up to additional liability.

But then I started thinking that if you left the EPO in its location and also added one on the Security Office (which is manned 24 hrs / Day). Once the EPO in the Data Center is Pushed it will alarm the Security Office but not shut down power. Then the Security officer will have 2 minutes to either initiate the EPO or Disable its operation. If no action is taken within the 2 minutes all power will be shut down.

The EPO is currently Sending a signal to the Shunt trip breakers which feed the Power Distribution Units and the Panel feeding CRAC Units.

-Ed
 

e57

Senior Member
Unfortunately the room is already wired to Article 645.
~~
But then I started thinking that if you left the EPO in its location and also added one on the Security Office (which is manned 24 hrs / Day). Once the EPO in the Data Center is Pushed it will alarm the Security Office but not shut down power. Then the Security officer will have 2 minutes to either initiate the EPO or Disable its operation. If no action is taken within the 2 minutes all power will be shut down.
If they want it gone - rewire it to avoid the EPO... DONE.

As for your solution... The letter of the NEC 'implies' little in the way it performs the function. It 'implies' it must be 'automatic' with the use of the word "cause" (meaning it lacks human interaction past iniation - and also note I am paraphasing... ) - but IMO doesn't say it can't be delayed with a warning signal and abort... And the NEC doesn't say it can't be reset... You know - like a self destruct button. "The UPS will shut down unless aborted by pulling the button back out in 5 - 4 - 3 - 2 - 1...."

But then again - if there was a need to shut somthing down - you want it to be immediate - say if you were the sucker locked on to a circuit watching your arm cook.... Would you be concerned about the safety of some bloggers musings? Or the many other very unimportant data uses that people protect with UPS systems.

Anyway I find this topic facinating - I once thought the EPO was always required - but in learning that - I found that some - particularly the local Fire Dept. want the EPO anyway for large UPS systems due to some trouble they had with a UPS battery fire.

And I have also learned there are a few other codes and standards on the topic... And a huge number of papers written on the topic. Here's a good one...
 

tkb

Senior Member
Location
MA
I have seen an EPO required by the FD because they wanted it and no other reason.
This was a room that didn't comply with 645.
 
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