Fire suppression - Medium Voltage Gear

[sstock]

I am concerned about a BOCA code "requirement" according to a local inspector requiring water sprinkler fire suppression in a concrete block room at a Waste Water Plant containing 4160V Variable Speed Drive Equipment. 1) I do not think any "suppression" is required and 2) it sure as heck can't be water!

Please help!

 

[charlie tuna]

Re: Fire suppression - Medium Voltage Gear

once there is a fire in that room --- the electricity will be "off" --- the idea is to contain the fire at any cost --the cost of the gear replacement means nothing to the fire code.

 

[sstock]

Re: Fire suppression - Medium Voltage Gear

Charlie:

Thanks for the reply.

I agree with you. However, most fire suppression systems activate all of the sprinklers in a building no matter where the fire is. If, say, a fire breaks out in a work shop area that sets off the sprinkler system, the sprinkler in this Medium Voltage electrial room will also go off possibly endangering anyone in that room.

I geuss I am just an ole hard headed sparky! Does the electrical gear in a room with a sprinkler system have to meet any specific enclosure standards, ie. NEMA 3R or NEMA 4?? I really don't feel good about putting a NEMA 1 enclosure in a room with sprinklers.

Again, Thank you for your help. This is my first visit to this site today and I really have enjoyed it.

 

[jbwhite]

Re: Fire suppression - Medium Voltage Gear

Originally posted by sstock:
However, most fire suppression systems activate all of the sprinklers in a building no matter where the fire is.

What systems are these. Most I have been arround are activated by the individual heads that have a fuse link that has to melt before the head goes off. Some systems set off entire areas, but none that I have seen set off a whole building.

 

[don_resqcapt19]

Re: Fire suppression - Medium Voltage Gear

sstock,

However, most fire suppression systems activate all of the sprinklers in a building no matter where the fire is.

You have been watching too many movies. It is very rare for a sprinkler system to be designed to operate in that manner. Those that do are called deluge systems and are only installed in high hazard occupancies such as aircraft hangers and chemical processing or storage areas. Systems in most occupancies have a melting alloy link at each head. Some even use a bimetal element that opens the sprinkler head on high temperature and then stops the water flow when the area is cooled, although most of this type are used in dwelling units.
Here is some information on deluge systems.
Don
edited to add link.

[ December 21, 2005, 01:25 PM: Message edited by: don_resqcapt19 ]

 

[sstock]

Re: Fire suppression - Medium Voltage Gear

Thank you don, jb, for the replies. I am a firm belieiver in dispelling any doubt about my ignorance.

The Halon, CO2 and other types of gaseous systems are used in some telcom applications and some in switch gear applications. Is this technology preferrable to fire suppression using water??

Thanks again guys!

 

[ron]

Re: Fire suppression - Medium Voltage Gear

Sprinkler is generally the cheapest. If you install a double interlock pre-action system, then you get the benefit of the inexpensive water with the reliability of gas release.
Double interlock pre-action requires a detector in the room to go into alarm, and a sprinkler head to fuse (reaching 165 degrees in many cases). If a head fuses elsewhere, then the switchgear room remains inactive, until called upon.
The downside of pre-action, is that if there is a fire that activates the detection and melts the 165 degree sprinkler head, and somehow wouldn't have damaged the remainder of the switchgear in that room, you'll be out of luck. But consider for a fire to melt a 165 degree sprinkler head, things are pretty bad already in this isolated room. Be sure to install curbs to reduce collateral damage in the event of an activation.

 

[don_resqcapt19]

Re: Fire suppression - Medium Voltage Gear

One thing that you need to remember is that there is only one way to extinguish an electrical fire...stop the flow of current. All the suppression systems can do is help prevent the fire from spreading from the electrical room and to extinguish the combustible parts of the electrical equipment after the current flow has stopped.
Don

 

[sstock]

Re: Fire suppression - Medium Voltage Gear

Don,

The installation will be well grounded and fused appropriately.

The best of both worlds would be to shutoff the power to the room in the event of a fire alarm event. This could be accomplished through a shunt trip type of mechanism connected to an external (from the unit/building) disconnect.

Also, this is an unmanned facility so threat to human life is greater when responding to an event rather that the event itself.

 

[jbwhite]

Re: Fire suppression - Medium Voltage Gear

if the building is unmanned look into a halon system.

of coarse if the problem is electrical and is not removed, even the halon will not prevent a reflash.

 

[realolman]

Re: Fire suppression - Medium Voltage Gear

There are sprinkler systems that have glass capsules in each individual head. Them babies'll drown you. No matter what the system, seems there could be failures.

Having sprinkler heads in a concrete block electrical room housing 4160 v stuff seems like a bad idea to me, as there should be nothing to extinguish, but the potential to spray a bunch of water on some fairly nasty ( and expensive )electrical equip. However, being no authority, I have no jurisdiction.

Maybe you could hang up some shower curtains. ( but then you'd have some fuel for the fire )

 

[ron]

Re: Fire suppression - Medium Voltage Gear

Scott,
Are you sure of the code requirement? Not many jurisdictions follow BOCA anymore. Most building codes have exceptions for rooms such as electrical rooms that may cause additional danger.

 

[sstock]

Re: Fire suppression - Medium Voltage Gear

Ron,

I am not sure of the code requirement either, however the local bldg inspector seems quite sure of himself.

The argument here is not for or against fire suppression around electrical equipment, the argument is: does it make sense.

This is an unmanned site, the electrical room is in a concrete block room, concrete floors and I believe the roof is steel truss and metal roofing material. The room has no other fuel for a fire nor is attached to any room that does. The fuel for a fire in a piece of switch gear, I would think, would not be great enough to sustain an fire for very long.

Hey, I really appreciate your input as well as those from all of the other respondents. It has been very helpfull and educational for me.

 

[realolman]

Re: Fire suppression - Medium Voltage Gear

Originally posted by sstock:
Ron,

The argument here is not for or against fire suppression around electrical equipment, the argument is: does it make sense.

IMHO no