Fire Alarm Panel - Fire Department

[ElectDesigner]

I would just like to know how fire alarm control panel in a building communicates to the local fire department. Is it a dedicated phone line that sends a unique signal to the fire dept.? What were previous methods used ?

 

[iwire]

Many ways, Here are a few I know

Municple alarm circuit with master boxes (literally a hard wired circuit that runs all around town). http://plaws.net/fire/box.html

Radio master box

Phone

Internet

 

[nhfire77]

I would just like to know how fire alarm control panel in a building communicates to the local fire department. Is it a dedicated phone line that sends a unique signal to the fire dept.? What were previous methods used ?

Everything Iwire said, plus UL listed celluar communicators and the most common is a (DACT) Digital Alarm Communicator/Transmitter over analog phone lines. 99% of those call a privately owned central station that contacts the local FD. Some FD's monitor dacts in house, but rare.

DACT's require regular (POTS) telephone service, which is in decline. DACTs via POTS are declining s....l....o....w...l...y to radio boxes, IP communicators cellular etc.

 

[MichaelGP3]

Some old(er) technologies not yet mentioned:

Reversing relays. Varitech and Keltron were manufacturers that made equipment to monitor these dedicated circuits. In my limited experience, these were monitored by both fire departments, police departments, and private central stations.

McCulloh circuits. In wide use prior to the advent of 2 line DACTs being approved for fire alarm monitoring, around 1984, as I recall. I have seen these monitored by private central stations and police departments (for fire alarm) on large university campuses.

 

[MichaelGP3]

There is another technology, whose name I'm not recalling, where a dedicated pair of wires handles the transmission of up to 5 distinct zones, based on differing frequencies applied.

 

[ElectDesigner]

Thanks guys!

 

[MichaelGP3]

The transmission technology I referred to in post #5 was used by Dorado, among others, but I don't know who invented or patented it.