Re: Why do we use facilities with EPO's?

>Seems like the EPO should be a logical AND with the fire
alarm system - 
>it only works AFTER you have an existing fire alarm in
the building.


No, no.  If the fire alarm system fails, the fire responders
need
to be able to hit the EPO and be sure that it works
anyways.
It has to be an absolute - firefighters have to know that
the
thing they hit was the only, and right, thing, and that
they
aren't going to die because they sprayed water on an
energized
but on fire electrical system backed by a 120 KVA UPS or
some
such.

Also, one should not wait for fire alarms to go off to
de-energize
a room in the clear presence of an electrical fire or major
short.
Preventing the fire is better than putting it out.


Telco central offices are somewhat of an exception in many
ways,
but just about anyone else should have a real live EPO.


-george william herbert
gherbertretro.com

On July 25, 2007 at 14:49 gherbertretro.com (George William
Herbert) wrote:
 > 
 > 
 > >Seems like the EPO should be a logical AND with
the fire alarm system - 
 > >it only works AFTER you have an existing fire
alarm in the building.
 > 
 > 
 > No, no.  If the fire alarm system fails, the fire
responders need
 > to be able to hit the EPO and be sure that it works
anyways.
 > It has to be an absolute - firefighters have to know
that the
 > thing they hit was the only, and right, thing, and
that they
 > aren't going to die because they sprayed water on an
energized
 > but on fire electrical system backed by a 120 KVA UPS
or some
 > such.

I worked three years with the boston fire dept, albeit quite
a few
years ago, and rode into many fires and don't generally
remember them
being much concerned about hitting *anything* with a
high-pressure
stream of water if it's on fire.

Remember all those rules you know about not using water on
electrical
or chemical fires? Doesn't really count if you have charged
fire hoses
and know what you're doing except in some special
circumstances (they
did foam things occasionally, very occasionally, foam costs
money!)

If they needed the power out, perhaps due to a gas hazard,
they
generally go for the power out in the street, calling in the
power co
if there's time or, well, one of the firefighters usually
knows how to
cut a building's power, between them they usually know just
about
everything they need to know about stuff like that.

I have no doubt if they saw an EPO and the room on fire
they'd hit it
immediately, why not, as you say it can only make things
safer (plus
or minus emergency lighting working but they should have
their own.)

But unless there was an explosion hazard I don't remember
there being
much concern. Water pressure and getting the equipment
positioned and
working was a concern (after life and limb of course.)

Put another way: Between a 120KVA UPS and a gang of
experienced
firefighters with charged hoses I'd put my money on the
firefighters
every time.

-- 
        -Barry Shein

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(snip)

> Put another way: Between a 120KVA UPS and a gang of
experienced
> firefighters with charged hoses I'd put my money on the
firefighters
> every time.
> 
> --
>         -Barry Shein

You realize the UPS systems we're speaking of are much
larger?  Usually 480
volt, many kVA.

Randy

On July 26, 2007 at 16:25 repsteinchello.at (Randy Epstein)
wrote:
 > (snip)
 > 
 > > Put another way: Between a 120KVA UPS and a gang
of experienced
 > > firefighters with charged hoses I'd put my money
on the firefighters
 > > every time.
 > > 
 > > --
 > >         -Barry Shein
 > 
 > You realize the UPS systems we're speaking of are much
larger?  Usually 480
 > volt, many kVA.

FWIW, do you imagine that's terribly large for urban
firefighters in
the big scheme of things, not just computer rooms?

My memory could be wrong but I remember the John Hancock
building, 60
stories, pulls about 1.5MW...I remember Boston Edison
mentioning this
in discussing a design I was working on of a supercomputer
facility,
that we were asking for more power than the hancock building
which was
ok but it presented..."challenges". Factories can
pull a lot of power
also (that room was never built.)

Anyhow, once you're beyond a pea-shooter I don't think
procedures for
firefighting vary a whole lot, other than some outliers.

	-b

> FWIW, do you imagine that's terribly large for urban
firefighters in
> the big scheme of things, not just computer rooms?
> 
> My memory could be wrong but I remember the John
Hancock building, 60
> stories, pulls about 1.5MW...I remember Boston Edison
mentioning this
> in discussing a design I was working on of a
supercomputer facility,
> that we were asking for more power than the hancock
building which was
> ok but it presented..."challenges". Factories
can pull a lot of power
> also (that room was never built.)
> 
> Anyhow, once you're beyond a pea-shooter I don't think
procedures for
> firefighting vary a whole lot, other than some
outliers.
> 
> 	-b

I guess my point was that it's safer to power off a UPS
system as best you
can before you shoot water at it.    Most
likely you are doing this at
somewhat close proximity, with step-down transformers
nearby, etc.

An EPO not only shuts down the power feed to the UPS, but
the UPS as well.
Which is a good thing.

A properly placed EPO and warning signs, as well as proper
training of your
customers and vendors should minimize the risks associated
with an EPO.

Look, if someone is hell bent to destroy your facility, EPO
or not, they
will succeed.

Randy

On Jul 26, 2007, at 6:59 PM, Randy Epstein wrote:
>
> I guess my point was that it's safer to power off a UPS
system as  
> best you
> can before you shoot water at it.    Most
likely you are doing  
> this at
> somewhat close proximity, with step-down transformers
nearby, etc.

Somewhat true.

> An EPO not only shuts down the power feed to the UPS,
but the UPS  
> as well.
> Which is a good thing.

The batteries still make pretty colors when you hit them and
start  
bridging things that shouldn't be bridged.  But if it's not
on fire,  
it is usually avoided by the fire department.
>
I'm posting on this as a 17 year volunteer fire department
member as  
well as a professional (albeit part-time, with the rest of
my time  
spent in network ops) fire marshal for a town in PA.

EPOs are great, and as a fire marshal I like them
(preventative) but  
they really don't figure in to the picture when I've got my 

firefighter hat (ok, helmet) on - because we just cut mains
to  
everything, and generally know what we're looking at and how
to  
handle it.  Any building in any reasonably juristiction that
has any  
"real" sized UPS most likely has not only a
pre-plan so the FD knows  
what is where, but also at least annual inspections. 
Chances are  
good the facility also has to hold a permit for the
number/capacity  
of the batteries in the unit (per IFC 105.7.2) and most
likely the  
fuel storage for the generators  (IFC 105.6.16).  Even in
your  
jurisdiction doesn't use that code, IFC and/or it's
ancestors provide  
the model code that most of the US operates on, so chances
are high  
there are similar restrictions/procedures/permitting
requirements.

Daryl

On July 26, 2007 at 18:59 repsteinchello.at (Randy Epstein)
wrote:
 > 
 > I guess my point was that it's safer to power off a
UPS system as best you
 > can before you shoot water at it.    Most
likely you are doing this at
 > somewhat close proximity, with step-down transformers
nearby, etc.

If you can stroll into the room and look around etc., sure,
why not. I
said that in the previous msg. We agree.

The note I was responding to asserted that it was necessary
to hit an
EPO before (direct) firefighting could commence, I wasn't
saying it
wouldn't be handy in some circumstances, just "not
entirely necessary"
(for firefighting.)

But getting to an EPO could be difficult if the room is
closed and
it's looking like it might be somewhere in excess of 450F
inside in
which case the usual approach is to smash/open a window or
door while
the others stand ready with a fully charged hose. Which is
why they'll
usually shut down power from outside the building if
needed.

By definition a room on fire is a room out of control*.

An important component of firefighting is working fast as
fires don't
usually get better by themselves. Well, actually they almost
all do
get better eventually on their own, when there's nothing
left to burn,
but that's not often an attractive option since the
available fuel
could be what you call your neighborhood.

Also, NOT TO BE TOO LITERAL MINDED, but isn't the point of a
UPS that
it has a lot of power even when it's not getting any
externally?

Doesn't hitting an EPO on a UPS at best only reduce the
electrical
hazard of hitting it with water a little bit?


* Interesting aside: In many venues, I know this is true in
Boston,
when a fire official declares a building on fire legal title
to that
building is automatically transferred to the fire dept
until
firefighting operations are declared ended.

-- 
        -Barry Shein

The World              | bzsTheWorld.com           | http://www.TheWorld.com
Purveyors to the Trade | Voice: 800-THE-WRLD        | Login:
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Software Tool & Die    | Public Access Internet     |
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On Fri, 2007-07-27 at 13:09 -0400, Barry Shein wrote:

> 
> Also, NOT TO BE TOO LITERAL MINDED, but isn't the point
of a UPS that
> it has a lot of power even when it's not getting any
externally?
> 
> Doesn't hitting an EPO on a UPS at best only reduce the
electrical
> hazard of hitting it with water a little bit?

Not an engineer, and not a firefighter, but I think I can
answer this
one.  

Yes, hitting the EPO would leave a lot of power potential
stored in the
batteries in the UPS.

The point of the EPO is to isolate those batteries from both
the
external (possibly high voltage) feed coming into the UPS
and to isolate
them from the inverters, transformers, power points (plugs)
and whatever
else is used in the build-out getting the power out of the
batteries and
to the equipment. 

This achieves a couple things. 

* It potentially removes one of the requirements of
combustion
(heat/energy input).  

* If the fire is not within/around the UPS itself, the
firefighters can
avoid the power that is still in the room.

* Removes the power from the wiring below your raised floor
so water
will not come in contact with the power present during
normal operation.

I'm sure that there are others out there that could give you
even more
reasons, but these are the ones that come to mind
immediately.

---
Tim Donahue