LS10144-001SK-E
Before You Begin Installation
3-6
3.7
Calculating Current Draw and Standby Battery
This section is for helping you determine the current draw and standby battery needs if you are using SK
addressable devices (Table 3-2) or SD addressable devices (Table 3-3).
3.7.1
Current Draw Worksheet Requirements
The following steps must be taken when determining 6820/6820EVS current draw and standby battery
requirements.
1.
You will use the Current Draw Worksheet to determine current draw and standby battery requirements. Use
Table 3-2 if installing SK SLC Devices and Table 3-3 if installing SD SLC Devices. For the 6820 /
6820EVS, the worst case current draw is listed for the panel, addressable devices, and all SBUS expanders.
Fill in the number of addressable devices and expanders that will be used in the system and compute the cur-
rent draw requirements for alarm and standby. Record this information in the Current Draw Worksheet on
Line A.
2.
Add up the current draw for all auxiliary devices and record in the table on Line B.
3.
Add up the current draw for all notification appliances and record in the table on Line C.
4.
For notification appliances and auxiliary devices not mentioned in the manual, refer to the device manual for
the current ratings.
5.
Make sure that the total alarm current you calculated, including current for the panel itself, does not exceed
6.0 A. This is the maximum alarm current for the 6820 / 6820EVS control panel.
If the current is above 6.0 A you will need to use a notification power expander(s) such as the Honeywell
Silent Knight 5495 or the 5895XL intelligent power expander, to distribute the power loads so that the 6820
/ 6820EVS or the power expanders do not exceed their power ratings. Refer to the current draw worksheets
provided with the 5495 or the 5895XL manuals so you do not exceed their power ratings.
6.
Complete the remaining instructions in the appropriate Current Draw Worksheet for determining battery size
requirements.
3.7.2
Current Draw Worksheet for SK SLC Devices
Use Table 3-2 to determine current requirements during alarm/battery standby operation SK SLC devices are
installed. The 6820EVS FACP supports up to a total of 1110 SLC devices, consisting of any combination of
Sensors and Modules.
6
Table 3-2 Current Draw Worksheet for SK SLC Devices
Device
# of Devices
Current per Device
Standby
Current
Alarm
Current
For each device use this formula: This column X This column = Current per number of devices.
Fire Panel (battery current draw)
1
Standby: 190 mA
190 mA
Alarm: 250 mA
250 mA
