Inspection and maintenance
For the quarterly and annual inspection
- Remove the panel front and inspect the battery and its connections to ensure they are in good condition.
- Disconnect the mains supply, and start an alarm condition with the sounders operative and
check that the batteries can supply the load current. - This test state should be maintained as long as is practical, to exercise the batteries to the fullest extent.
For the 5 year inspection
The batteries must be replaced with new batteries, since the 5 year replacement period is based on the manufacturing date of the batteries, not the installation date.
Stand-by battery calculation guide
The standby time of the fire alarm panel after the mains has failed depends on the quiescent loading of the panel, the alarm load of the panel, and the capacity of the batteries. To determine the capacity of batteries required for any given stand-by period, the following formula should be used:
Standby Time in Ahr = 1.25 x «TxA) + H x (P+Z» I
The multiplier 1.25 is present to account for lost capacity over the life of the batteries.
H = Number of hours standby required
P =The quiescent current of the Panel =O.025A
This figure is with the Mains failed, beeper operative and the Power Supply and General Fault indicators lit. If there are other quiescent drains on the Panel then these must be added in.
Z = The total quiescent current of all zone devices
As a guideline, the quiescent current of most modern detectors is typically 0.00005A (50~), and that
of manual call points is zero.
A = The total alarm current of the sounders (plus any other devices connected to other alarm outputs).
T =The amount of time in hours required for the alarm (most commonly being half an hour).
Example 1:
The panel has 70 detectors each consuming 50MA each, 20 Sounders at 20mA each, the required
standby time is 24 Hours, and the required alarm time is 0.5 Hours.
Z = 70 x 0.00005 = 0.0035A
P 0.025A
A =20 x 0.02 :: 0.4A
H 24
T= 0.5
Standby Time in Ahr :: 1.25 x ((0.5 x 0.4) + 24 x (0.025 + 0.0035))=1.1AHr
Therefore, batteries with at least 1.1Ahr capacity are required.
Example 2:
The panel has 100 detectors each consuming 50MA each, 40 Sounders at 20mA each, the
required standby time is 72 Hours, and the required alarm time is 0.5 Hours.
Z= 100 x 0.00005 = 0.005A
p:: 0.025A
A 40 x 0.02 =0.8A
H =24
T 0.5
Standby Time in Ahr = 1.25 x ((0.5 x 0.8) + 72 x (0.025 + 0.005)) == 3.2AHr
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