Guide to Fire Alarm Basics: Power Supplies
2) Next total standby capacity is required by multiplying the total system standby current by the required 24 hours to achieve the required standby capacity in AMP-HRS. The same is done with the alarm capacity, however, instead of 24 hours, the current is multiplied by either 5 minutes (0.083 hours) or 15 minutes (.25 hours) to achieve the ...