Calculating The Battery Size; 1: Nfpa Battery Requirements; 2: Selecting And Locating Batteries - Fire-Lite MS-9200UDLS Manual

Power Supply Calculations

7.4 Calculating the Battery Size

Use Table 7.4 to calculate the total Standby and Alarm load in ampere hours (AH). This total load
determines the battery size (in AH), required to support the system upon loss of primary (AC)
power. Complete Table 7.4 as follows:
1. Enter the totals from Table 7.3 on page 161, Calculation Columns 2 and 3 where shown
2. Enter the NFPA Standby and Alarm times (refer to 'NFPA Requirements' below)
3. Calculate the ampere hours for Standby and Alarm, then sum the Standby and Alarm ampere
hours
4. Multiply the sum by the derating factor of 1.2 to calculate the proper battery size (in AH)
5. Write the ampere hour requirements on the Protected Premises label located inside the cabinet
door
Total Standby Load, Battery Powered
(from Table 7.3 Calculation Column 3)
[ ]
Total Fire Alarm Load, Battery Powered
(from Table 7.3 Calculation Column 2)
[ ]
Sum of Standby and Alarm Ampere Hours
Multiply by the Derating Factor
Battery Size, Total Ampere Hours Required
Table 7.4 Total Secondary Power Requirements at 24 VDC
7.4.1 NFPA Battery Requirements
• NFPA 72 Local, Proprietary, Central, Auxiliary and Remote Fire Alarm Systems require 24
hours of standby power followed by 5 minutes in alarm
7.4.2 Selecting and Locating Batteries
Select sealed lead acid batteries that meet or exceed the total ampere hours calculated in Table 7.4 .
The control panel can charge batteries in the 7 AH to 18 AH range. The control panel cabinet is
capable of housing batteries up to 18 AH. Batteries larger than 18 AH require a UL listed external
battery charger and cabinet such as the BB-26, BB-55F or other UL listed external battery cabinet.
162
Required Standby Time
(24 hours)
X[ ]
Required Alarm Time
(for 5 min., enter 0.084,
for 10 min., enter 0.168)
X[ ]
MS-9200UDLS Series Manual — P/N 52750:H 4/14/2014
Calculating the Battery Size
= AH
= AH
= AH
X 1.2
= AH