System Options Menu
Page 99
Once mains power is restored, the control unit deactivates any AC Fail outputs and
logs the mains restore. A user can reset the alert and deactivate any General Fault
outputs by pressing the navigation and entering the access code again.
External PSUs
If the system has an EXP-PSU fitted, or if an external PSU is connected to a zone with
type External PSU AC Fail, the control unit treats a mains fail at the external PSU in the
same way as a mains failure at the control unit, with one difference concerning reporting to
the ARC:
If the control unit and external PSU both experience individual mains failures, but starting
at different times, as long as those mains failures overlap and together last for more than
the
Mains Fail Delay
period, the control unit will activate any AC Fail outputs and report a
mains fail to the ARC. If the mains failures do not overlap, and are both individually shorter
than the
Mains Fail Delay
period, the control unit logs the events and activates any
General Fault outputs, but will not send a report to the ARC.
If the external PSU is allocated to a partition, and mains power at the external PSU is off
for longer than the Mains Fail Delay period, the report to the ARC can show that the
partition experienced a mains fail. This report is additional to any report the control unit
might send concerning a mains fail at the control unit.
The control unit provides different methods of reporting to the ARC. For mains fail
reporting each method differs in the detail that it can send:
SIA/CID reports can indicate mains failure in individual partitions.
Fast Format reports cannot show details of mains failure in partitions, only mains
failure as a system-wide fault. This means that although the system can report that
a mains failure occurred, it cannot show whether the failure was in the control unit
or in an external PSU.
Plug-by outputs cannot show details of individual partitions for a mains failure. Like
Fast Format, they can only report mains failure as a system event.
Event Sequence
Report Timing
The control unit mains fails and the remote
PSU mains fails within 10s.
The control unit waits for the mains fail
delay and then starts a keypad alert and
reports a mains fail.
There is a delay of more than 10s but less
than the mains fail delay between a mains
fail at the control unit and a mains fail at
the remote PSU.
The control unit illuminates the red keypad
LED after 10 seconds of the initial mains
fail and then starts waiting for the selected
mains fail delay. However, when the
remote PSU mains fails the control starts
a keypad alert and reports mains fail
immediately.
There is a mains fail at the control unit,
followed by a mains fail at the external
PSU after the selected mains fail delay
has expired.
The control unit lights the red keypad LED
after 10 seconds of the initial mains fail
and then starts a keypad alert and reports
mains fail at the end of the selected mains
fail delay. The control then logs the mains
fail of the remote PSU.
