Battery Calculations
Your local Authority Having Jurisdiction (AHJ) is requesting battery calculations for the following installation. He is requiring 24 hours of standby time followed by 15 minutes of alarm time.
Three (3) type A modules with standby current of 100ma and alarm current of .17amps; three (3) type B modules with standby current of 26.1ma and alarm current of .0267 amps; one (1) main control board with standby and alarm current of .137amps; 37 smoke detectors – standby and alarm current .0003amps; Ten (10) horns .018 alarm current; Ten (10) 15cd strobes – alarm current .04amps; Two (2) 110cd strobes – alarm current 145ma; and Ten (10) 75cd speaker/strobes with alarm current of .2amps.
1. What is the combined standby current?
A. 3450 milliamps
B. .5264amps
C. N 5264amps
D. 452 milliamps
2. The requirements for an intrinsically safe system can be found where?
A. Central station system
B. Voice evacuation System
C. Personal Emergency Response System
D. Non-required monitored system
3. What is the combined alarm current?
A. 2.2 amps
B. 3.6082 amps
C. 3.3453 amps
D. 14.24 amps
4. What is the normal required safety factor percentage?
A. 5
B. 10
C. 15
D. 20
5. What is the “calculated” battery size?
A. 36.5 amps
B. 43.14 amps
C. 13.54 amps
D. 16.24 amps
6. What is the industry standard battery size that needs to be installed?
A. 12
B. 17
C. 36
D. 64
7. What is the minimum calculated battery requirement for this system?
A. 36.5 amps
B. 13.54 amps
C. 43.14 amps
D. 16.24 amps
8. How much standby current is used by the horns?
A. 0
B. 1.456 amps
C. 300 ma
D. ¾ of an amp
