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Fire Alarm -- Installation

I have a question on how something works.
Douglas Krantz -- Fire Alarm Engineering Technician, Electronic Designer, Electronic Technician, Writer







I have a Question

Firstly,

Thanks Mr. Douglas for your excellent website.

I wrote to you to ask about the relay contacts of a Conventional Fire Alarm Control Panel. Can we use these contacts to shut down the elevator in case of fire?

Waiting your answer

Signed W E

Answer

Usually those contacts activate with any alarm. To keep the elevator from being captured when a smoke detector in any part of the building goes into alarm, the smoke detectors in the elevator lobbies have to be wired to the elevator using relay bases on the smoke detectors.

Another person to ask about this is the elevator inspector. The elevator inspector will be able to tell you what each smoke detector should do about capturing the elevator, and the inspector will also be able to tell you if the detectors are supposed to be alarm sounding detectors or supervisory detectors. (Supervisory Detectors are really alarm detectors, but they show a yellow light on the panel and don't sound the horns and strobes in the building.)

Douglas Krantz

Reply

Thanks a lot. Hope to you good health.







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Douglas Krantz

Describing How It Works
facpdoug@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
.