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Fire Alarm -- Description

The sign above the fire alarm pull station says to call 911. That is because the fire alarm system will n0t do that automatically.
The sign over the pull station did say "Attention." The question is, "during an emergency, will a resident even notice the sign after going past it for years?"
Douglas Krantz -- Fire Alarm Engineering Technician, Electronic Designer, Electronic Technician, Writer






How good are those Call 911 signs above pull stations?

By Douglas Krantz

The Fire Marshal didn't have the authority to require the owner to upgrade the fire alarm system to use off-site monitoring. Because the building didn't have any off site monitoring, above each pull station was a sign saying "Attention -- When Fire Alarm Sounds -- Call Fire Department -- 911."

Delayed Dispatching of the Fire Department

  • Yes, the building did have a fire alarm system
  • Yes, the alarm system did sound off
  • Yes, this part of the building is a total loss
Any resident hearing the fire alarm was supposed to call 911. But when the fire alarm did sound off, the halls were full of smoke and the residents of this 8 unit apartment building weren't stopping to make phone calls; they were fleeing for their lives. The fire pretty much took all their belongings.

Will They Call?

It's common knowledge that fire alarm systems call the fire department automatically. That isn't always true, but people believe it anyway, and they're surprised when the system doesn't call. Did the residents here even know that the fire alarm system wouldn't call the fire department?

An even more burning question, when the halls were full of smoke and the residents were fleeing for their lives, could they remember to call 911?

Off Site Monitoring of the Fire Alarm

Those at the Central Monitoring Station (CMS) aren't near the fire so they don't have to run for their lives. From somewhere else, not on site, they professionally watch the building's fire alarm system. If the fire alarm system sounds off, they call the fire department on a timely basis.

As a method of redundancy, the residents should call 911 anyway. But when residents are fleeing for their lives, having the CMS call the fire department is the more reliable method.

Expense of Off Site Monitoring

Off-site monitoring for a small apartment building is a complicated and expensive proposition.

Most CMSs require monthly or annual charges, this is added to the cost of getting signals to the CMS in the first place.

In Addition:
  • If the building is out of range of fire alarm monitoring radio receivers, there's no help there
  • Cable internet isn't all that reliable yet, and there are few fire-certified cable modems
  • Cell phone type communication is even less reliable because of the automatic and constant shifting from one tower to another
  • Internet monitoring requires the building to use all fire-certified local internet equipment (fire-certified hubs, routers, servers, etc.)
  • If plain-old-telephone lines are used, monthly charges on 2 business lines are required
When deciding whether or not to monitor off-site, these cost factors affect the decisions made by the building owners. Sometimes it's considered just too expensive.

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Cost to Residents -- The Money Question

The cost of monitoring -- using phone lines, paying the CMS monthly charge, and maintenance -- may well be $90 a month. This is easily the cost whether there are 8 units (like here) or 80 units. Of course, because landlords aren't made out of money, costs like this have to be passed on to tenants.

Question -- to have the fire alarm system monitored off-site, if you were a resident here, would you be willing to pay an extra $12 to $15 a month ($144 to $180 a year) in rent?






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Douglas Krantz

Describing How It Works
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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
.