SilentKnight SKE-450 Voice Evacuation Control Panel - Manual (Page 67)

151267 9-1
Section 9
Battery Calculation
9.1 Calculating Current Draw and Standby Battery
This section enables you to determine the current draw and standby battery needs for your
installation (18 Ampere Hours maximum).
Batteries larger than 18 AH will not fit into the main control cabinet, and must be housed in
the RBB Accessory Battery Cabinet. See Section 3.8.2 for battery installation.
Lines A through D have been completed for you. Complete the remaining instructions in
Table 9-1 to determine battery size requirements.
* If less than 50 watts are used, calculate 45 mA per watt.
Table 9-1: Current Draw Calculations
Device
Number of
Devices
Current per Device
Standby
Current
Alarm
Current
Main Control Panel 1
Standby: 140 mA 140 mA
Alarm: 590 mA 590 mA
SKE-ZN4 1
Standby: 45 mA mA
Alarm: All Channels 250 mA mA
SKE-ZN6 1
Standby: 35 mA mA
Alarm: All Channels 120 mA mA
SKE-SRM 1
Standby: 30 mA mA
Alarm: 30 mA mA
SKE-V70 1
Standby: 10 mA mA
Alarm: 70 mA mA
A Current Subtotals: mA mA
Notification Devices Refer to device manual for number of devices and current ratings.
Full Load (50 watts)* Alarm: 2250 mA mA
B Current Subtotals: mA mA
C Total current rating of all devices in system (add TOTALS OF A-C) X .001: A A
D Number of standby hours. (24 or 60 for NFPA 72, chapter 1, 1-5.2.5): H
E Multiply lines C (standby current) and D: Total standby AH AH
F Alarm sounding period in hours. (For example, 5 minutes = .0833 hours) H
G Multiply lines C (alarm current) and F: Total alarm AH AH
H Add lines E and G. (AH = Ampere Hours) Total AH required AH