ADT Unimode 400 Multi-Net Installation Manual page 207

Calculating the Battery Requirements
Unimode 400 Installation PN 50710:A 10/22/97
Use Table G-4 to determine the battery capacity needed for the system:
Secondary Non-Fire X
Alarm (current from
column 3 in Table G-2)
Secondary Fire Alarm X
Load (from column 1 in
Table G-2)
Sum Column for Total Secondary Amp Hours calculated =
Multiply by the derating factor x 1.2 =
Battery Size – Total Secondary Amp Hours Required
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The following notes apply to Table G-4:
1. NFPA 72 Local and Central Station systems require 24 hours of standby power
followed by 5 minutes in alarm.
2. NFPA 72 Auxiliary and Remote Station Systems require 60 hours of 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 25 AH, the system requires a separate BB-55 battery enclosure
for two PS-12550, 55 AH batteries. If the total exceeds 55 AH, an Uninterruptable
Power Supply with sufficient amp-hour capacity is needed. The Uninterruptable
Power Supply must be UL-listed for Fire-Protective Signaling.
Use Table G-5 to sum the standby and alarm loads which determine the battery size, in
amp-hours, needed to support the fire alarm system. Select batteries that meet or
exceed the Total Amp-Hours calculated and that are within the acceptable battery
charger range (12-55 AH). Write the amp-hours requirements on the Protected
Premises label.
Battery Size Voltage Rating
12 AH 12 volts
25 AH 12 volts
55 AH 12 volts
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Required Secondary Non-Fire Alarm
Standby Time (24 or 60 hours)
Required Fire Alarm Standby Time
(for 5 minutes, enter 0.084; for
15 minutes, enter 0.25)
Number Part Cabinet
Required Number Size
two PS-12120 ADT-CAB-A3, B3, C3, D3
two PS-12250 ADT-CAB-A3, B3, C3, D3
two PS-12550 BB-55
= Non-Fire Alarm
Secondary Amp
Hours
= Secondary Fire
Alarm Amp Hour
Requirement
AH
G-5