Calibrating An Fdnet/C-Net Detector Line - Siemens FS720 Commissioning, Maintenance, Troubleshooting

Calibrating an FDnet/C-NET detector line

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Connecting a sub-stub to a loop
13 Calibrating an FDnet/C-NET detector line
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Building Technologies
Fire Safety
General
WARNING
Impermissible line configuration
An impermissible line configuration can cause the alarm devices connected to this
line to be supplied with insufficient power in the event of a fire. This prevents the
alarm from sounding in the corresponding parts of a building. This can cause
serious injuries or death.
● Make sure that all lines of a line card have a permissible line configuration by
calibrating them successfully. You will find information about the requirements
for a permissible line configuration in the 'Planning detector lines' chapter of
the document 'A6V10210362'.
Line calibration enables users to check whether sufficient power is being supplied
to all devices in an installed line during commissioning and ongoing operations; the
power supply can even be checked in the event of an alarm. This is particularly
helpful when the line topology or power-relevant configuration parameters of a line
are changed.
Another objective of line calibration is to determine how much additional line
resistance ΔR is possible before the line devices fall below the required supply
max
voltage in case of corrosion, gradual cable breakage, or thermal drift.
In the event of thermal drift, the line resistance R
In an unheated warehouse, the difference in temperatures under the ceiling in
summer and winter could amount to 50 °C. This could lead to the line resistance
being ≈ 20 % higher in summer than it is in winter.
The line calibration also shows the maximum possible current consumption of all
line devices per line card.
Time of a line calibration process
The time of a line calibration process depends on how this has been configured in
the 'Cerberus-Engineering-Tool' for each individual line.
The following configuration modes are available:
● 'Automatic with manual recalibration'
● 'Automatic without manual recalibration'
● 'Manual'
● ' - (disabled)'
In the default settings, a line is set to 'Automatic with manual recalibration' in the
configuration.
You will find information on configuring the line calibration in document
'A6V10210424'.
The duration of a line calibration consists of a 45-second base time plus about 1
second per installed 'Voice alarm sounder beacon/Voice al. sound. beacon base'
device on the line to be calibrated. This means a line with 252 'Voice alarm
sounder beacon/Voice al. sound. beacon base' devices can be calibrated in about
5 minutes.
increases by ≈ 0.4 %/ °C.
Line
A6V10210416_j_en_--
2018-08-29