System calculations
B.20 EST3 Installation and Service Manual
Cabinet battery
Use the following method to calculate the minimum ampere-
hour capacity of a battery required in order to operate a panel in
the absence of AC power. Battery calculations must be
performed separately for each cabinet in the system.
Determine the total amount of current in milliamps required by
all of the components that derive power from the battery while
the panel is in standby mode. Multiply the total amount of
standby current by the number of hours that the panel is required
to operate in standby mode while on battery power.
Determine the total amount of current in milliamps required by
all of the components that derive power from the battery while
the panel is in alarm mode. Multiply the total amount of alarm
current by the number of minutes that the panel is required to
operate in alarm mode while on battery power. Divide the result
by 60 to convert minutes to hours.
Add the total amount of standby current and the total amount of
alarm current then divide the result by 1000 to convert to
ampere-hours. Multiply this number by 1.2 to add a 20% safety
factor to the calculations.
EST3 is UL Listed for battery operation durations as follows:
• Standby: 60 hours max.
• Alarm: 30 minutes max.