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5.5 Demonstration
Mode
IMPORTANT NOTE
!
5.6 EN54-20
compliance
In normal use, the detector remains in a reduced sensitivity mode for 24 hours whilst it
gathers information about its environment. For purposes of demonstration, e.g. to verify
a new installation, this may be disabled by putting the detector into “Demonstration
Mode”. This special operating mode bypasses the 24-hour learning process and allows
the detector to operate at a high sensitivity after only 15 minutes learn time.
To enter Demonstration Mode, the detector must be in FastLearn mode. Whilst FastLearn
is running, hold down the front panel <RESET> button and whilst holding this,
simultaneously press the <TEST> and <ISOL> buttons. The <RESET> and <ISOL>
buttons do not need to be enabled for this function.
When entering Demonstration Mode, the detector front panel LCD display will show the
legend Demo mode and the time and date on which this was invoked.
Demonstration Mode should only be used for demonstrations. It should not be used as a
substitute for normal operation as the alarm settings in this mode are based solely on
the sparse data gained during the 15-minute FastLearn period. Over time, this would
lead to nuisance alarms due to normal variation in the detector’s environment. To cancel
Demonstration Mode, invoke a new FastLearn (see section 3.4.8).
The installation must be designed using PipeCAD software, which is provided free on the
CD shipped with each detector. After designing the installation including pipes, endcaps
and sampling holes, enter the detector type. To select the detector type, select Options,
select Calculation options, and then select the detector from the Type drop-down list.
Select “Options” “Calculate” or click on the calculator icon. The software will prompt you
to choose from “Use set hole sizes” “Best flow balance” and “Max. permissible transit
time”. Select the appropriate option and click “OK”. The results for each pipe (“View”
“Results”) show calculations for each sampling hole on the pipe with the nearest to the
detector at the top of the screen, and the endcap hole at the bottom.
For EN54-20 compliance the transport time of the last sampling hole shall be checked
following all installation and proven to be less than or equal to that determined by
PipeCAD.
The classification of each sampling device configuration and associated sensitivity
settings are determined ” by the column headed “Hole sensitivity % obs/m which shows
the predicted sensitivity for each hole. For the installation to comply with EN54-20
depending on the class of installation, each sampling hole must be no less sensitive
than the following:
Class A: 0.62% obs/m
Class B: 1.95% obs/m
Class C: 4.65% obs/m
The calculation can be further refined by leaving a working detector in the protected
area for at least 24hrs at the intended alarm factor for the installation (this could be
done before or after installation). The detector sensitivity can be read from the
“Sensitivity” figure on the histogram screen of the Remote software supplied with each
detector. Click "Options" and then click "Calculation options" to open the "Hole
calculation options" dialog box. Enter the sensitivity value obtained from the practical
test, and then click OK. The new calculated value will use the the real sensitivity from
the practical test.
The PipeCAD software will determine the classification of any used configuration.
Commissioning and periodic system tests must involve smoke tests to verify that the
system performs as expected and enters Fire 1 alarm within the time determined by
PipeCAD from the farthest hole. The detector sensitivity must also be inspected to
ensure it has not radically fallen from the installed figure. If it has changed for any
reason. the new figure must be re-entered into PipeCAD and the recalculated hole
sensitivities must be confirmed to be within the class limits shown above.
Stratos HSSD-2 • INSTALLER’S HANDBOOK • Iss. 12
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