45
R4
R5
R3
R6
R8
Ld10
R23
Ld9
R22
Ld7
R20
Ld6
R19
Ld13
R18
U6
RAVEL RE-127-RP-DISP
Door Cutout
for PCB fixing
PCB Mounting Hole
PCB Mounting Hole
Figure -7
Chapter 7: Battery Calculation
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 control panel under the fail of the AC
Power Supply. Complete the table 7.4 as follows:
1.
Enter the NFPA standby and alarm times (refer to NFPA
requirements below).
2.
Calculate the ampere-hours for standby and Alarm, and then
sum the standby and alarm ampere-hours.
3.
Multiply the sum by the derating factor of 1.2 to calculate the
proper battery size (in AH).
4.
Write the ampere hour requirements on the protected premises
label located inside the cabinet door.
TABLE 7-4: Total Secondary Power Requirements at 24 VDC
System current (
S
) = Quiescent Current = 50mA
