beautypg.com

Emergency power supply, Specifying battery capacity, Battery rated capacity – Siemens FC700A User Manual

Page 54: Ageing of battery, Calculation, Capacity values for standard configurations, 23 emergency power supply, 1 specifying battery capacity, 2 capacity values for standard configurations, 1 battery rated capacity

background image

Emergency power supply

54

Siemens Building Technologies

007836_a_en_--.doc

Fire & Security Products

03.2004


23

Emergency power supply

23.1 Specifying battery capacity

23.1.1 Battery rated capacity

The battery rated capacity is based on the discharge over a period of 20 hours

Faster discharge causes a loss of capacity:

Discharge over 12-hour period:

9% loss (K = 1.1)

23.1.2 Ageing of battery

With increasing age, the battery suffers a loss of capacity

Allow a safety factor for ageing
(Total quiescent current y 1.25 or battery capacity y 0.8)
> 24h in conformity with DIN VDE 0833, part 2, no safety factor is necessary

23.1.3 Calculation

Battery capacity must be calculated individually!
Formula: Ah = A x h x 1.25 (poss. x K)

Ah

= Battery capacity in Ah

A

= the sum of the quiescent current for all modules

h

= Required operating period in hours

1.25

= Safety factor for ageing

K

= Capacity loss if discharge is over considerably less than 20 hours

23.2 Capacity values for standard configurations

Battery capacity requirement for

Configuration Quiescent

current

12h 24h 72h

128 detectors addressable

7outputs

235mA

3,8Ah

7,0Ah

16,9Ah

16 collective lines

7 outputs

315mA

5,1Ah

9,4Ah

22,6Ah

Notes:

Equipped with 1 control terminal B3Q700

Discharge over a 12-hour period, 9% loss of capacity taken into account

Factor 1.25 for ageing taken into account at 12h and 24h (72h without safety
factor)

Without remote transmission equipment

Only quiescent current taken into account