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Fire Suppression

Fire Alarm Panels are sometimes sold as Do Everything panels.
Combination Fire Alarm panels (and everything but cook dinner panels) are sold to accounting departments as a way of saving money because they are only buying and maintaining one system. The problem with combining systems is that when something goes wrong with one part of the system, nothing else will work.
Douglas Krantz -- Fire Alarm Engineering Technician, Electronic Designer, Electronic Technician, Writer






Should the Main Fire Panel Release the Fire Suppression?

By Douglas Krantz

According to NFPA Code, is it permissible to use the common area fire alarm control panel to release fire suppression systems?

A releasing fire alarm system is really just a specialized fire alarm system. It has been tested for use in the way it is intended, and then listed for that use.

If the common area fire alarm system has been tested and listed to release the different kinds of fire suppression systems, the answer is yes.

Common Fire Suppression Release Systems activated by Fire Alarm Panels:
  • Preaction System -- allows the sprinkler system to flood and spray water once it loses air pressure
  • Deluge System -- activates the sprinkler system so it will spray water everywhere
  • Dry Chemical Systems -- Releases FM200/CO2/Halon Type airborne chemicals to deny oxygen to a fire

Allowed Versus Should

The code says yes, combining the common fire alarm system with the release system is allowed -- but the real question is should the two systems be combined?

Consequences

If a common area fire alarm system has a false alarm, the consequence of a false alarm is that people go out into the parking lot and the fire department arrives when it is not needed. If it is a business, there is also a loss of productivity.

On the other hand, a false activation of the fire suppression system is still all of the above. But added to all of the above is the cost:
  • Of resetting the suppression system (sometimes very expensive)
  • Of repairs to the building (the damage may be extensive)
  • Of damaged equipment (including computer servers)
  • Of the loss of valuable paper records and materials (sometimes irreplaceable)
  • Of the loss of data stored in a computer system (banks and retailers get upset when this happens)
  • Of downtime for the business communications (some businesses have world wide issues)
  • Of... Well, the list goes on and on
The bottom line -- the damage incurred from false alarms on a common area fire alarm system is nothing compared to the damage that can be incurred from a false activation on a fire suppression system.

Two Separate Systems

There is very little that can go wrong with a stand-alone fire suppression control system.

There are a few smoke or heat detectors, there's the release apparatus, a small control panel, and the wiring is restricted to just a few rooms. The smoke or heat detectors are strictly involved with only that panel, and the only way to activate the fire suppression system is with that panel.

When activated, the fire suppression control panel may send an alarm to the main fire alarm panel, but the common fire alarm control panel cannot activate the fire suppression system.

The main disadvantage to installing separate systems is seen by those paying the bills and those calling for service.

Two separate systems do cost a little more to install -- when it comes to bidding, this is an issue.

Also, the two systems often require two different companies to test and service because one company specializes in fire suppression systems while another company specializes in large common area fire alarm systems.

There are, however, issues involved with combined systems that balance out the cost savings.

System Troubles

The release portion usually covers one or two rooms, while the common area fire alarm system is installed throughout the entire building. Just the sheer number of devices on the common area system is ten times, a hundred times, or even a thousand times the devices and wiring used for a stand-alone suppression release system.

Doubling or tripling the number of devices means the possibility of things going wrong is doubled or tripled.

When combined, if something goes wrong with the main system, the release system has the same problem. If the Common area fire alarm system is separate from the release system, there is just that much less to go wrong with the release system.

Of course, if the release system can't do any more damage to the business than the common fire alarm system, combining the two systems is not an issue. If, on the other hand, the suppression system can do a lot of damage, adding the building wide, common fire alarm system to the suppression system becomes a huge issue.

Troubles and Service

If combined, making repairs anywhere in the building to the common area fire alarm system can affect the release portion of the system.

Remember, all electronic systems eventually have breakdowns, including fire alarm systems. When the common area fire alarm system is having troubles, no one really knows just what it is going to do. Working on a smoke detector in another part of the building can potentially cause a release.

Accidental releases have huge consequences, possibly liability issues.

Choosing Service Companies

The service company may easily change over time because, to the accountants who do most of the choosing, one fire alarm service company is like another.
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Even though they're selected to do maintenance and testing (sometimes they're chosen because they're the low bidder), some service companies are not as well acquainted with the releasing system as other companies. Because they may not know about the release system or what to do about it, they can get into trouble.

Separate or Combined

When making the decision to combine systems, remember, combining the release system and the common area fire alarm system has long term consequences.







Douglas Krantz

Describing How It Works
writer@douglaskrantz.com
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612/986-4210

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Electrical Flow


On this website, most references to electrical flow are to the movement of electrons.

Here, electron movement is generally used because it is the electrons that are actually moving. To explain the effects of magnetic forces, the movement of electrons is best.

Conventional current flow, positive charges that appear to be moving in the circuit, will be specified when it is used. The positive electrical forces are not actually moving -- as the electrons are coming and going on an atom, the electrical forces are just loosing or gaining strength. The forces appear to be moving from one atom to the next, but the percieved movement is actually just a result of electron movement. This perceived movement is traveling at a consistent speed, usually around two-thirds the speed of light. To explain the effects of electrostatic forces, the movement of positive charges (conventional current) is best.

See the explanation on which way electricity flows at www.douglaskrantz.com/
ElecElectricalFlow.html
.