EPO Button @ Mantrap in Data Center

[ed downey]

I am currently working on a Data Center that is being designed around Article 645.

I have multiple exits out of the space that are double doors that have an EPO at the exit.

I have one location that has a mantrap (door from data center to small room then another door to the corridor). Per 645.10 it requires an EPO at the Principal exit doors.

Would we be required to add an EPO at the Mantrap door since it is exiting into another room and not an exit corridor?

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,

Ed

 

[tkb]

I would say, no EPO required.
Like you highlighted, the EPO is only required for the principal exit doors.

 

[benaround]

I would say, no EPO required.
Like you highlighted, the EPO is only required for the principal exit doors.

or,

The 'mantrap' could be the principal exit and it won't have one ?

 

[e57]

This mantrap may be a security short cut - and very well may be the principle exit in a sistuation were the EPO would actually be needed...

 

[ron]

Mantraps are typically the primary pedestrian exit and thus the principal.

 

[dbuckley]

Given the mantrap room is within the secure area, then you should fit an EPO button in there too, however anyone chooses to interpret code.

Standard note about not using series contactors for data centre EPOs, as when the fail (and eventually they always do) they take out the data centre. Use shunt trips.

If the fire spressent boys are putting in holdoffs, they should think about what they want in this room too.

 

[DataCenterGuy]

Totally agree. The Mantrap is there because it's THE Principle Entrance, which in my mind makes it also a Principle Exit since in most high-end Data Centers people are required to card in AND out. In an emergency, supposedly the Mantrap will unlock so that the fire department can get in easily. They're the ones who most want the EPO, so I don't see any question about this at all. It gets an EPO.

 

[e57]

Now why is it - would anyone want all eggs in the same basket and put the UPS - it's batteries, and the data equipment in the same room anyway? One would assume some minor seperation by fire rated partition would solve some serious issues... Cooling for one would be reduced. And furter limited access to UPS, and actual data center security as well. Since much of the reasoning for wanting an EPO is the second source of power, and the caustic and flamable batteries with it. Since some of them can be set up to use a - door bell button if you really wanted to seriously cheese out - if it's not in the room no need to EPO it... Then if you still wanted to '645' the Data Center proper you could use something more 'difficult' to shut off... Like a hook-stick... "What's this broom handle in the ceiling for???" - Noooooo!





(Kidding a hook-stick may not be considered readily accessible....)

 

[dbuckley]

Now why is it - would anyone want all eggs in the same basket and put the UPS - it's batteries, and the data equipment in the same room anyway?

That one puzzles me every time too.

Why do I (as an IT person) want power engineers stalking around my fragile electronics carrying posh car batteries? Same goes for cooling - do I really want an CRAC engineer with a blowtorch or drill putting metal filings into the air?

These nasty things should all be outside the computer space. Then the IT space can be secured to fewer people.

 

[DataCenterGuy]

Modern Data Center Design

Modern Data Center Design

That's the direction we try to go today, with the major Cooling outside of the computing area. Not only keeps trades and their stuff away from the computers, but improves cooling efficiency as well if its done right. But it takes more space, which is always a problem. Power is another matter. Distributed UPS designs (at the end of each cabinet row) are promoted to provide more flexible growth, but they haven't really caught on. Poor economy of scale. But even with a big UPS outside of the room (as it should be, but sometims can't because of space again), today's power demands are making PDU's, or at least Breaker Panel Cabinets, at the ends of each row the common approach to reduce wire lengths for the huge number of circuits. That still puts electricians in the room, and with the Arc Flash concerns, perhaps even in a suit as well. (Scares the Hell out of IT folks!) And now we're also doing more cooling right at the equipment, which puts Mechanics in the room as well. We solve one problem, and the demands of the industry create another !!

 

[dbuckley]

And now we're also doing more cooling right at the equipment, which puts Mechanics in the room as well. We solve one problem, and the demands of the industry create another !!

yaas, a single rack that goobles 30KW+ of juice, unheard of just a few years ago...