Hochiki FIRElink-400CM - Manual (Page 40)

Page 40 of 58 FIRElink-400 Air Sampling System – Installation Manual
© 2010 Hochiki Europe (UK) Ltd 9-5-0-346/ISS4/OCT10
6.7 EN54-20 Compliance
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 in the “Type” drop-down list in “Options” “Calculation options”.
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.
“Transit time” shows the smoke transit time to the detector from each sampling hole. For EN54-20, this
must be below 120 seconds from every hole.
The column headed “Hole sensitivity % obs/m” 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. Enter this figure into the PipeCAD calculation under “Options”
“Calculation options”. “Detector sensitivity”. Clicking on “OK” will update the hole sensitivities to the figure
expected for the actual layout.
Commissioning and periodic system tests must involve smoke tests to verify that the system performs as
expected and enters Fire 1 alarm within 120 seconds 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.
The settings of a compliant system should be recorded, as it is possible by changing certain
programmable functions to make the system non-compliant. If functions are changed, it is recommended
that the system is retested if continuing compliance is in any doubt.
IMPORTANT
NOTE
For EN 54-20 compliant installations the detector requires that the flow thresholds be
set manually to ±6% of the nominal value, after the FastLearn phase is completed. For
example, if the flow rate is 64% after the completion of the FastLearn period, the user
must manually set the low flow threshold to 58% and the high flow threshold to 70%.