NFS2-640/E Installation Manual —
P/N 52741:P2 7/10/14
39
Backup-Alarm Switches
Installation
3.10 Backup-Alarm Switches
Backup alarm switches are provided that enable NACs
and the alarm relay to activate during a backup alarm
condition. If the main board’s microcontroller fails and
an alarm is reported by any detector or a monitor
module that has backup reporting enabled, the NAC
will turn on if the corresponding switch was enabled.
The alarm will activate during microcontroller failure
regardless of the settings of switches SW1–SW4.
•
SW1 - NAC#1
•
SW2 - NAC#2
•
SW3 - NAC#3
•
SW4 - NAC#4
So, for example, if SW1 and SW4 were enabled at the time of an alarm during microcontroller
failure, NAC#1 and NAC#4 would activate. Follow sequence of steps in Section 3.2 “Installation
Checklist”, Table 3.1; this is Step 7.
!
WARNING:
Do not enable the BACKUP option switch for any of the four Notification Appliance Circuits (NACs) if
they are used for releasing functions!
Figure 3.22 Backup Alarm
Switches
CP
U2
-6
40
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