Functional Description; Response Behavior; Self-Monitoring - Bosch ADW 511A Installationsanleitung

Linear heat detector ADW 511A Transafe
6

Functional description

The Transafe ADW 511A works on the basis of the physical law governing the volumetric
expansion of a gas in a pneumatically sealed system and the corresponding increase in pres-
sure.
The sensor tube functions as a pneumatically air-tight system. This is mounted in the moni-
tored area and sealed at one end with an end screw cap. The other end is connected to the
detector box, whereby the sensor tube is connected to the fully electronic pressure sensor
and mechanical testing device (motor with pressure pump) inside the housing. The entire
pneumatic system contains normal ambient air.
The operating software is stored in the socketed EPROM. The EEPROM is for saving system-
specific parameters and event measurement values. The system includes a watchdog switch
for monitoring the processor. In the event of an incorrect program sequence the switch will be
activated and trigger a watchdog reset (page 52).
6.1

Response behavior

The ADW 511A records two types of temperature data: differential and maximum.
During differential evaluation, the pressure sensor continuously measures the absolute pres-
sure in the sensor tube. The sensor signals are evaluated by the microprocessor.
The ADW 511A will display an ALARM DIFF if the pressure increases disproportionately quickly
during a defined time period. Pressure changes caused by atmospheric temperature fluctua-
tions or high traffic volumes in road tunnels will not trigger an alarm. Response sensitivity can
be set via the 16-step program selection switch on the PC board (see page 50).
During maximum evaluation, the system will record and evaluate a gradual increase in pres-
sure over a longer time period which does not fall within the detection area of the differential
evaluation.
An ALARM MAX is triggered when a particular limit value (e.g. T = 40°C) is reached. Further-
more, a temperature gage in the detector box measures the current ambient temperature and
compensates for the maximum evaluation in accordance with the prevailing temperature con-
ditions. The temperature gage itself will trigger an alarm if the temperature inside the detector
box rises above 70°C. The activation threshold is permanently programmed at 70°C.
6.2

Self-monitoring

An automatic system check is performed at regular intervals. A precisely defined overpressure
(target value) is created in the sensor tube during the test. The check is performed by default
every 8 hours. The time interval can be changed via the PC to 1, 2 or 4 hours where required.
Causes for deviations from the target value:
No pressure increase (below target value)
Pressure increase too low (below target
value)
Pressure increase too high (above target
value)
Bosch Sicherheitssysteme GmbH
Deviation
Installation Guide
Functional description | en
Cause
– Sensor tube is open, leaking or not
connected
– Pressure pump defect
– Drive motor defect
– Leaking sensor tube
– Pinch in the sensor tube, current
length of sensor tube different to the
installed tube length
BDL -F.01U.004.036 | A2 | 2006.11
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