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Fire Alarm -- Description

Lights on a Fire Alarm Panel - Green for Power - Red for Fire Alarm - Amber or Yellow for Supervisory and Trouble
The green light indicates the panel has power and is working. The red light comes on when there is a Fire Alarm. Amber lights come on when a system the panel is Supervising is in Alarm or when there is trouble with the Fire Alarm System.
Douglas Krantz -- Fire Alarm Engineering Technician, Electronic Designer, Electronic Technician, Writer






What are those Lights and Buttons on the Fire Alarm System For?

By Douglas Krantz

You're now in charge of the building, be it an apartment building, office building, business complex, or industrial complex and now you have to deal with the fire alarm system. What is it, what does it do, and how do you deal with it?

Purpose of the Fire Alarm System

First off, a fire alarm system detects fire and tells people to get away from the fire, helps control the spread of smoke and fire, and usually notifies a monitoring company to call the fire department.

Instructions

A Fire Alarm Control Panel has lights to indicate its status:
  • Green Light Normal -- Power is on and the Fire Alarm System is operating normally.
  • Red Light Alarm -- A zone or device is in alarm. The lights will indicate zone or the display will show the location of the alarm. Building wide horns and strobes will activate. Call the fire department.
  • Yellow Light Supervisory -- The fire alarm system is indicating another system that is not normal and is in immediate need of attention. The panel is making an internal noise on its sounder. The fire department does not need to be called.
  • Yellow Light Trouble -- The fire alarm system itself has a problem that needs to be fixed. The panel is making an internal noise on its sounder. The fire department does not need to be called.
  • Yellow Light Monitor -- The fire alarm panel is showing that there may be a problem in the near future. The panel is making an internal noise on its sounder. The fire department does not need to be called.

Fire Detection

A Fire Alarm System detects a fire:
  • Automatically -- it looks for smoke, heat, or activation of a fire suppression system like water flowing in the building sprinkler system.
  • Manually -- it waits for someone to manually pull a pull station.

Actions of the Fire Alarm System

Once a fire is detected, a series of events occur:
  • The building wide horns, speakers, and fire strobes activate telling people to get to safety.
  • Smoke control goes into action, sometimes closing fire doors, shutting down air handling equipment, closing air dampers, capturing the elevator.
  • Usually, an outside monitoring company is automatically called about the alarm, and the monitoring company calls fire department. (Don't count on it though, if there is fire, and something may have gone wrong with the phone lines, the call to the monitoring company may not get through. Make sure you also call the fire department.)

What Should You Do When the Alarm Sounds?

What should you do once these events start?
  • Don't silence the alarms -- the fire alarm system is making the noise to tell people there may be a fire - let it do its job. Call the fire department -- you may think the fire alarm system will take care of calling, but it may not. Besides, the fire department likes extra calls.
At this point there are two possibilities:
  1. If you have not been given official company policy telling you what you should be doing -- leave the building with everyone else and let the fire department deal with the fire. (Also, no matter what you think the fire alarm system is going to do, remember to call the fire department yourself.)

  2. If you have official company policy telling you what to do -- follow that policy, and:
    • Call the fire department-- let them know the situation
    • Read the fire alarm panel-- it tells you where the fire is located
    • Don't breathe smoke-- it is toxic and it can kill you
    • Don't let the fire get between you and your way out

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Just a note -- fire alarm systems are life safety devices -- they work in absolutes:

You absolutely have to reset a red light alarm to return a fire panel to normal; a person has to be there to silence and reset.

You absolutely cannot reset a yellow light supervisory, trouble or monitor condition; the cause of the condition has to be repaired before the panel will reset.






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Douglas Krantz

Describing How It Works
writer@douglaskrantz.com
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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
.