VESDA by Xtralis
VESDA VLC-EX Product Guide
www.xtralis.com
27
8
Battery Backup
The power supply for the VESDA VLC-EX detector may be switched to a back up battery in the event of the
supply being disrupted. The size of the battery back up is determined by local standards and codes, the total
power required by the system, back up time required, allowance for reduction in capacity with age and
expected temperature variations.
Note:
It is recommended that batteries be changed as per the battery manufacturer’s specifications or as
per the relevant local codes and standards.
8.1
Backup battery size calculation sheet
Normal Load @ 24 VDC
Full alarm load @ 24 VDC
Equipment
Load mA
Number
Total
Load mA
Number
Total
Detector
225
245
Remote Display
90
110
Remote Programmer
50
(backlight
off)
110
(backlight
on)
Hand-held Programmer
50
(backlight
off)
110
(backlight
on)
Other 24 V loads
Total mA
Total mA
X
X
Standby hours
Alarm hours
=
Standby capacity
Alarm capacity
Total capacity = S Alarm capacity
Divided by 1000 for standby capacity
Multiplied by battery factor (Normally 1.25)
Table 8-1: Calculating the size of backup battery
Note:
The PSU is usually located in a non-hazardous area and may supply power via a Zener barrier (or
other similar energy limiting device) but this is not required for safe operation of the VESDA VLC-
EX in normal operation. Refer to the notes in Section 6.1 for further information.
Summary of Contents for VESDA VLC-500-EX
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