Bosch DOW 1171, Руководство по эксплуатации

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Radio Frequency Fire Detection System Installation/Configuration Notes | en 11
Bosch Sicherheitssysteme GmbH Operation Guide 2016.04 | 6.0 | 4.998.120.885
4 Installation/Configuration Notes
When planning the RF fire detection system it must be ensured that the individual RF
detectors have an optimum radio connection to the RF interface module. In a building, the
range for the RF fire detection system generally depends on the reflection and absorption
behavior of the materials used and the applicable ceiling and wall construction. There is no
need for a visual line between the individual radio components.
Depending on whether the configuration or the materials of the wall and ceiling constructions
are known, there are various options to plan the RF fire detection system:
–
Planning with manual calculation of the attenuation (see chapter Planning the RF Fire
Detection System, page 11 )
– Planning with DZW 1171 Radio Test Unit (see chapter Planning a RF Fire Detection System
with DZW 1171 Radio Test Unit, page 13 )
– Planning using PC or laptop with Radio Spy 1 Field Strength Measuring Unit and Software
4.1 General Limits
– Recommendation: Maximum of 10 x FK 100 LSN Interface Modules per LSN ring.
– Maximum of 30 RF fire detectors or 10 RF manual call points per interface module.
Interface modules, RF fire detectors and RF manual call points count in each case as one
LSN element (e.g. 1 interface 15 RF fire detectors = 16 LSN elements).
– A maximum of 127 LSN elements are permitted for each LSN ring.
– Attenuation of a transmission path < 90 dB
4.2 Planning the RF Fire Detection System
To be able to create an optimum radio connection, the attenuation of a transmission must be
< 90 dB. The attenuation values of the construction elements located on the transmission path
in question (walls, ceilings etc.) must also be added to determine the actual attenuation at the
mounting location in the case of attenuation owing to the distance.
The attenuation for the individual transmission paths, depending on distance and including
the construction elements installed, can be calculated from the following tables.
Where the distance is doubled, the attenuation increases by approx. 17 dB.
Distance 5 m 10 m 15 m 20 m 25 m 30 m 40 m
Attenuation 40 dB 57 dB 67 dB 74 dB 79 dB 83 dB 90 dB
Table 4.1: Attenuation Values Depending on Distance
Construction Attenuation
Partition 1 dB
dry brick walls or concrete walls/ceilings 6 dB
Lime sand brick 6 dB
Sand lime brick planning elements 10 dB
Wood framed or wood paneled walls 10 dB
Damp brick wall 10 dB
Coated gypsum plasterboard (double wall) 15 dB
Steel-reinforced concrete 30 dB