e1453b
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Fire & Security Products
Siemens Building Technologies Group
12.2001
1.3 Fire detection system line network
1.3.1 Separate line network
The fire detection system must be basically operated via a separate line network. The
common use of a main cable (e.g. PTT) is not recommended.
Never use low voltages and extra low voltages in the same main cable.
1.3.2 Design
According to block diagram.
Maintain separation of low voltage and extra low voltage cables.
1.3.3 Wiring material
Basically, standard telephone and extra low voltage installation material can be used.
Twisted cable is preferred and is sometimes essential.
In order to ensure alarm activation in any situation, we recommend cables which are fire-
resistant over a longer period.
1.3.4 Existing line networks
These networks can be basically used if capacitances, line and insulation resistances
comply with the data specified.
1.3.5 Explosion hazard areas
For explosion-hazard areas, comply with the guidelines according to document e1204,
«Fire detection in explosion-hazard areas».
1.3.6 Electromagnetic influence (EMI)
All equipment is largely protected against EMI.
Nevertheless, the following precautions are necessary:
Maintain the greatest possible distances from thyristor control cables, high voltage
lines, lightning protection systems, transmitter cables etc.
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