System Sensor PDRP-1001 User Manual

System Events

3. System Operation

PDRP-1001 Instruction Manual  PN 50734:D0  04/06/01

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Upon actuation of a single-zone initiating device, a red alarm LED will illuminate to indicate whether 
Zone 1 or Zone 2 is in alarm.

In addition to the LED, a single-zone alarm will activate the Alarm Relay; the piezo and NAC #1 will start 
sounding. In alarm condition, the piezo will generate a steady tone. The piezo can be silenced by pressing 
the trouble silence switch. If the fire is extinguished before a second zone alarm is activated, return the 
system to normal standby condition by pressing the reset switch inside the panel and holding it for three 
(3) seconds.

When the first alarm occurs, the panel will function as described above.

Upon the occurrence of a second alarm, the second alarm LED will illuminate, NAC #2 will energize, and 
the solenoid valve(s) will energize to activate releasing devices.

The total power being provided to the system’s power supply should not exceed the current draw during 
fully loaded panel operation. Brownout circuitry annunciates degradation of the incoming AC voltage 
supply. A brownout condition is annunciated when the AC power decreases. When the brownout threshold 
is reached, the system reacts as if AC power is totally lost:

• Battery backup begins supplying power to operate the control panel
• General Trouble Relay contact transfers
• Green AC Power LED turns off
• Yellow System Trouble LED illuminates
• The piezo will sound one second on, one second off, and repeat until the Trouble is cleared.

When the AC voltage returns or increases above the brownout threshold, the green AC Power LED will 
illuminate. The power supply circuitry will return to primary power functions and begin to recharge the 
backup battery supply.