PERTRONIC INDUSTRIES LTD
VESDA
®
PSU
Installation Note
PERTRONIC INDUSTRIES LTD
0520-VESDA PSU Operating Instruction Issue 9, 200804
Operation:
The
VESDA
®
Power Supply Unit
incorporates a 1.5 amp switching regulated power supply with
voltage monitoring and battery test facilities.
The VESDA PSU was initially designed for use with the VESDA range of aspirating detectors. It
supports the following Brigade connected (24 Hour Standby) detectors:
Model
Maximum
Charge Current
Battery Size
LaserSCANNER 1
0.82A
12AHr
LaserPLUS 1
0.82A
12AHr
LaserCOMPACT 4
1.4A
18AHr
LaserFOCUS : VLF-500
1
0.84A
12AHr
LaserFOCUS : VLF-250
2
0.9A
12AHr
If more detectors or batteries larger than 12Ahr are required, use the 24V/4A Switch Mode PSU.
If the peak current drawn from the power supply exceeds 2.5A, then the output load should be
connected directly to the Battery terminal block—the in-line polyswitch is rated 2.5A
Indicators:
The green
Mains On
LED illuminates when the Mains supply is present.
The red
Overload-Recharge
LED illuminates when the Charger load exceeds 1.3A.
The yellow
Autotest
LED glows during the daily power supply test. The
Power Supply Unit
monitors the Battery voltage and also performs a Battery Capacity Test every 24 hours by
reducing the power supply voltage to 22.0Vdc for 60 minutes.
If the
RESET
switch is pressed for more than 1 second, the 60 minute Battery Test starts and
the
Autotest
LED turns ON. Subsequent Battery Tests occur every 24 hours from this time.
Fault Monitoring:
The Fault relay—located at the bottom centre of the PCB—is normally energised, de-energising
after a delay to indicate that a defect has occurred.
Delays for the various Fault types are shown in the following Table:
Fault
Value
Encoded Pulse
Delay Before Fault
Relay Activates
High Battery/Charger Voltage
> 28.8Vdc
1st
55 minutes
Low Battery (When Mains is off
or the Charger in Test mode)
< 24.3Vdc
2nd 55
minutes
Battery Missing (Charger in Test
mode)
Battery Missing (Charger not in
Test mode)
< 23.6Vdc
Checked
every
10 secs
3rd
25 seconds
15 seconds
Mains Lost
4th
1 hour
Encoded Fault Indications and Fault Relay Delay times
Four non-latching Fault conditions are detected:
The yellow
Battery
Fault
LED indicates which fault conditions are active.
The indication is immediate for
High,
Low
Battery, Battery Missing,
and
Mains Lost
faults; but the fault relay is delayed in de-energising, as the table above shows.
Momentary operation of the
RESET
switch restarts the 24-Hour Timer. The battery test
commences 23 hours after reset, and then every 24 hours subsequently.
The power supply frequency is the reference for the timing functions. The
Power Supply
adjusts
automatically for 50Hz and 60Hz supplies. When the Mains supply is absent, an internal clock
provides reference until the Mains supply is restored.
