D9412GV4/D7412GV4 v2.03 | Installation and System Reference Guide | 22.0 NFPA 72 Fire Alarm
A
lications
.
Bosch Security Systems, Inc. | 7/16 | F01U265457-09 156
22.4 Central Station or Local Systems
Central Station or Local Systems require 24 h of standby plus 5 min of alarm operation at the end of
the 24-hour period. A single battery is sometimes adequate for central station systems, but two
batteries must be installed to meet the basic standby requirements for a local system installation. Use
the battery ampere-hour (Ah) calculations to confirm compliance. The formula in Table 45 includes the
calculation for 5 min of alarm operation at the end of the 24-hour period, as well as a 10%
contingency factor that allows for depletion of battery capacity with age.
Because of changing regulations, verify the necessary time with your local AHJ (authority
having jurisdiction).
Table 45: Central Stations or Local Systems Ah Calculation Formula
Total B
1
Hours Total C
1
Alarm Operation
2
Contingency Total Ah
3
( ________ x 24) + ( ________ x 0.083) + 10% = _________
1 Refer to Table 41 on page 152.
2 Value = Minutes of alarm operation
60
3 Total Ah requirements must not exceed the Ah capacity of batteries:
One D126 Battery = 7 Ah
Two D126 Batteries = 14 Ah
One D1218 Battery = 17.2 or 18 Ah
Two D1218 Batteries = 34.4 or 36 Ah
22.5 Remote Station or Auxiliary Systems
Remote Station or Auxiliary Systems require 60 h of standby plus 5 min of alarm operation at the end
of the 60-hour period. A B520 Auxiliary Power Supply Module with additional batteries installed in a
separate D8109 or D8108A Enclosure might be required in the system to meet the basic standby
requirements for a remote station or auxiliary system installation. Use battery Ah calculations to
confirm compliance. The formula in Table 46 includes the calculation for 5 min of alarm operation at
the end of the 60-hr period, as well as a 10% contingency factor that allows for depletion of battery
capacity with age.
Because of changing regulations, verify the necessary time with your local AHJ (authority
having jurisdiction).
Table 46: Remote Station or Auxiliary Systems Ah Calculation Formula
Total B
1
Hours Total C
1
Alarm Operation
2
Contingency Total Ah
3
( ________ x 60) + ( ________ x 0.083) + 10% = _________
1 Refer to Table 41 on page 152.
2 Value = Minutes of alarm operation
60
3 Total Ah requirements must not exceed the Ah capacity of batteries:
One D126 Battery = 7 Ah
Two D126 Batteries = 14 Ah
One D1218 Battery = 17.2 or 18 Ah
Two D1218 Batteries = 34.4 or 36 Ah
To Next Page
Loading...
Need help?
General
