1 2 5 3 0 / 1 2 5 4 0 O W N E R ' S M A N U A L
P/N 447203 Issue I
XII-1
XII. APPENDIX-E: GLOSSARY
Alarm Signal
. A signal indicating an emergency requiring immediate action, such as an alarm for fire
from a manual station, a waterflow alarm, or an automatic smoke detector.
Alarm Silence Inhibit
. An option that prevents a human operator from silencing the notification
appliances for a preset period of time.
Alarm System
. A combination of compatible initiating devices, control units, and notification appliances
designed and installed to produce an alarm signal in the event of a fire.
Alarm Verification
. A preset option that causes the control unit to verify alarms originated by smoke
detectors before indicating an alarm.
Annunciator
. A remotely located, electrically powered display, separate from the control unit, containing
LEDs or lamps to indicate the states of the fire alarm system.
Audible Signal
. An audible signal is a sound made by one or more audible notification appliances, such
as bells or horns, in response to the operation of an initiating device.
Authority Having Jurisdiction (AHJ)
. The organization, office, or individual responsible for approving
equipment, installation or procedure.
Auto-Silence
. The capability of a control to automatically silence the notification appliances after a
preset period of time.
Auxiliary Relays
. Control relays that energize only during alarm conditions that are used to either apply
power to or remove power from other equipment during an alarm condition.
Class A Circuit
. An initiating device or notification appliance circuit within which all components remain
fully functional, even though a single open or ground exists in the circuit.
Class B Circuit
. An initiating device or notification appliance circuit within which some or all components
may be disabled with a single open or ground exists in the circuit.
Detector - Smoke, Ionization Type
. A detector employing the principle of smoke’s effect on an electrical
current flowing in an ionized air chamber.
Detector - Smoke, Photoelectric Type
. A detector employing the photoelectric principle of reflection or
obstruction of light by smoke.
End Of Line (EOL)
. A device used to terminate a supervised circuit.
General Alarm
. A term usually applied to the simultaneous operation of all the notification appliances on
a system.
Ground Fault
. A trouble condition in which a low resistance has been detected between the system
wiring and conduit ground.
Initiating Device
. A manually or automatically operated device such as a manual pull station, smoke
detector, heat detector, waterflow switch or tamper switch.
