Siemens CERBERUS AlgoRex Series Installation Manuallines page 10

1.3.7 «Collective» detection lines
6
Fire & Security Products
Siemens Building Technologies Group
«Collective» detection lines can only be installed as stub lines. According to the type of
control unit or regulations, 20...32 fire detectors can be connected per stub line.
New systems: Twisted cable, in exceptional cases with very powerful electromagnetic
influence shielded and twisted.
Existing systems: Single and parallel conductors are permissible.
Line resistances and line capacitances see document e1508 «Connection factors, line
resistances and capacitances».
Type of cable Application
Twisted, min. 7 turns Generally recommended
Shielded, twisted Essential in areas where EMI is critical
min. 7 turns e.g. X-ray rooms, radar systems, transmitter stations, proximity to thy-
ristor controls etc.
Non-twisted Cable in existing systems can be utilized without difficulty with mini-
mum remaining risk
Not recommended for new systems
Shielded/non-twisted Cable in existing systems can be utilized without difficulty with mini-
mum remaining risk
Not recommended for new systems
Upper level
Ground floor
CT..
Basement level
Fig. 4 Block diagram «collective» detection system
L11
L10
L9
24V
L8
L7
L6
L5
È È È È È
Ex
È È È È È
L4
24V
2
FDC 1,5mm
CC/CI..
L3
L2
L1
24V
24V
DC
SB DC1192
240V~/10A
e1453b
12.2001