4 Conventional Products—6424 Projected Beam Type Smoke Detector
Three Light Emitting Diodes (LEDs) at the receiver indicate the status of
the detector (see Table 1).
Table 1: LED Indication
Color
Status
Red
Alarm
Yellow
Trouble
Pulsing Green
Standby Operation
The alarm signal latches the alarm contact in the receiver. There are three
methods of resetting the receiver:
●
momentary interruption of power to the receiver
●
activation of the remote test/reset station model RTS451
●
the local reset button located behind the rear door in the receiver
A trouble signal automatically resets upon removing the cause of trouble.
In addition to these indicators, there are four LEDs on both the receiver
and the transmitter which are used as a beam alignment aid. No additional
equipment is needed for alignment of the beam.
Each detector contains one Form-A (normally open) contact for alarm
signals and one Form-B (normally closed) contact for trouble signals.
Supervision of power is accomplished by installing a power supervisory
End-of-Line (EOL) relay module (model A77-716B) at the end of the
detector power circuit. When power is applied to and through the
detectors, the EOL power supervisory module is energized. The relay
contacts, along with the detector’s trouble relay contacts, provide a closed
series circuit in the control panel’s Initiating Device Circuit (IDC). A loss
in power or a trouble condition at the detector causes the respective EOL
or trouble relay to open, resulting in a trouble signal at the control panel.
