Siemens SIGMASYS C, Manual

Page: 79 / 138

11 Power supply
I max = maximum current in A
Δ
u = maximum permitted voltage drop of 0,5 V
χ
= special electric conductance for copper 58 m / mm
2
Ω
L = line length (forward and reverse line) in m
q = conductor cross section in mm
2
Cross sections over 2.5 mm 2 must be reduced with the help of series terminals in
the SIGMASYS control and indicating panel.
11.5 Current requirement calculation
The maximum current requirement for the control and indicating panel is to be calculated us-
ing the form When calculating the alarm current, only the largest fire section should be taken
into account (largest current requirement of the system), i. e. when tripping the fire section
with the monitored alarm lines and the monitored control lines (max. value during simultane-
ous activation is decisive).
To calculate the power requirement for the Sinteso detector periphery you can also use the
Excel tables in the PSP (Product Support Platform).
https://psp.sbt.siemens.com
11.6 Measuring the battery capacity
The size of the battery capacity is determined on the basis of the system’s idle current and
the required bridging time. The battery bridging times are defined as follows in compliance
with VDE 0833 or VdS 2095:
Bridging time VDE 0833 / VdS 2095
If a standby power supply is available for the GMA and spare parts are provided and
mains supply failure is detected at any time (responsible service permanently busy)
and the maintenance technician is permanently available. 4 hours
If the fault is detected at any time (responsible service permanently busy) and the
maintenance technician is available within 24 hours
.
30 hours.
If the conditions set for 4-hour and 30-hour operating time are not satisfied. 72 hours.
Table 26: Bridging time
On the basis of the control and indicating panel’s and the external device’s alarm current in
the event of an alarm. The alarm current for the alerting facility of the fire section with the
highest current requirements must be available for 0.5 hours (see VdS 2095).
The battery capacity (K) depends on the bridging time (tü) required and is calculated using
the following formula:
Bridging time t
Ü
= 4 h K = 1.56 * (t
Ü
·* I
R
+ 0.5 * I
AL
) [Ah] and
Bridging time t
Ü
≥ 30 h K = 1.25 * (t
Ü
·* I
R
+ 0.5 * I
AL
) [Ah]
I
R
= idle current or recharging current
I
AL
= alarm current
The formulae are marked on the calculation form.
Multifunctional Danger Control and Indicating Panels SIGMASYS C and M (M-Modules) 71 / 128
Best.Nr. A24205-A337-B970 – Edition 12 (03/07)