ACPS-610/E Manual —
P/N 53018:A1 07/31/2007
49
Calculating the Battery Requirements
Power Supply Calculations
5.2 Calculating the Battery Requirements
5.2.1 Calculating the Battery Capacity
Use this table to determine the battery capacity needed for the system:
The following notes apply to Table 5.8:
1.
NFPA 72 Local, Proprietary, Central Station, and Remote Station systems require 24 hours of
standby power followed by 5 minutes in alarm.
2.
NFPA 72 Auxiliary systems require 60 hours or standby power followed by 5 minutes in
alarm.
3.
Batteries installed in a system powered by an automatic starting engine generator need to
provide at least 4 hours of standby power.
4.
Factory Mutual requires 90 hours of standby for deluge-preaction systems.
5.
Emergency voice/alarm communications systems require 2 hours of operation in the alarm
condition. Due to the sporadic nature of voice operation, however, NFPA 72 permits 15
minutes of operation at a maximum connected load to equal 2 hours of normal use.
6.
If the total exceeds 200 AH, an Uninterruptable Power Supply with sufficient amp-hour
capacity is needed. The Uninterruptable Power Supply must be UL-listed for Fire-Protective
Signaling. (Refer to pages 24 and 36 for trouble connections and FACP programming.)
7.
The following battery derating factors must be used for Canadian installations using an
ACPS-610 charger. Derating factors are subject to local AHJ approval.
• For 12 – 26 AH capacity, use derating factor of 1.2
• For 55 AH capacity, use derating factor of 1.8
• For 100 – 200 AH capacity, use derating factor of 2.5
Current (amps)
X
Time (hours) Required
=
_________AH
Secondary Non-Fire
Alarm (Standby) Current
(from Table 5.6)
________________
X
Required Standby Time (hours)
________________
=
__________AH
Secondary Fire Alarm
Load (from Table 5.7)
________________
X
Required Fire Alarm Time (minutes):
*
________________
=
__________AH
Sum Column for Total Secondary Amp Hours calculated
=
__________AH
Multiply by the derating factor x 1.2 (See Note 7)
=
__________AH
Battery Size – Total Secondary Amp Hours Required
=
__________AH
* Following are decimal conversions for standard numbers of minutes:
5 minutes
10 minutes
15 minutes
30 minutes
60 minutes
120 minutes
0.084
0.167
0.250
0.5
1.0
2.0
Table 5.8 Secondary Power Standby and Fire Alarm Load