Calculating The Battery Size - Honeywell HPF24S8 Installation Manual

Power Supply Requirements
Table 6.3 contains three columns for calculating current draws. For each column, calculate the
current and enter the total (in amperes) in the bottom row. When finished, copy the totals from
Calculation Column 2 and Calculation Column 3 to Table 6.4 on page 41.
Calculate Column 1
Primary, Non-Fire Alarm Current
Device Type
Qty
Main Circuit Board 1
Power Supervision [ ]
Relay
NAC/Output #1
NAC/Output #2
NAC/Output #3
NAC/Output #4
Current Draw from
TB4 Terminals 9 &
10
Sum each column Primary Non-Alarm =
for totals

6.4 Calculating the Battery Size

Use Table 6.4 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 power supply under the loss of AC
power. Complete Table 6.4 as follows:
1. Enter the totals from Table 6.3 on page 40, Calculation Columns 2 and 3 where shown.
2. Enter the NFPA Standby and Alarm times. Refer to "NFPA Battery Requirements" on
page 41.
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).
40
(amps)
X (current draw)
Total Qty
=
X [ 0.091] =
X [ 0.025] = [
[
[
[
[
[ ] =
Primary Alarm =
Table 6.3 System Current Draw Calculations
Calculate Column 2
Primary, Fire Alarm Current
(amps)
X (current draw)
Total
=
1 X [ 0.145] =
] X [0.025 ] =
] X [ ] =
] X [ ] =
] X [ ] =
] X [ ] =
[ ] =
HPF24S Series Power Supplies — P/N 52751:D3 5/11/2010
Calculating the Battery Size
Calculation Column 3
Secondary, Non-Fire Alarm Current
(amps)
Qty X (current draw) =
1 X [ 0.065] =
[ ] X [ 0.025] =
[ ] =
Secondary Alarm =
Total