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St ra tos HS SD -2 • INS TA LLE R’ S HAN DB OOK • Is s. 12
c. Maximum recommended total sampling pipe length is 200 metres. This is 4
lengths of 50 metres, or 2 lengths of 100 metres. In order for the installation to
conform to EN54-20, pipes must conform at least to EN61386-1 Class 1131.
d.
Sampling pipes must have capped ends. The end cap should be drilled with
a sampling hole normally between 4 or 5mm diameter and free from burrs.
Sampling holes should normally be 3-4mm diameter or as calculated by PipeCAD
and free from burrs. Each pipe run should not have more than 25 holes. Pipe
transit time must not exceed 120 seconds and an approved type of pipe must
be used for installations conforming to LPCB requirements. When drilling holes in
the sample pipes, or cutting off lengths of pipe, ensure that all swarf and debris is
removed from the pipe.
This guide holds true for average sampling pipe lengths, but if using long pipes
(typically more than 60 metres total), performance may be improved by making
the sampling holes near the ends slightly larger than those nearer the detector.
Although by no means essential, it must be recommended that if in doubt,
PipeCAD® be used to ensure that transit times, balance of suction and individual
sampling point sensitivity are within desired limits.
Before installing the detector the local standards for installation of aspirating detection
systems must be consulted as these standards differ throughout the world. Specific
advice for one country may not be applicable to another. The following is a brief set of
guidelines on installing detectors.
■
It is recommended that system design and installation is carried out by suitably
experienced and trained personnel.
■
The detector will normally be mounted at a level where there is easy access to the
unit for configuration and programming.
■
Unused sampling pipe inlets must be closed. For advice on pipe layout design
consult the ‘System Manual’ and contact Kidde Products Ltd. help line (see page 3) in case of difficulty.
■
The exhaust air from the unit must not be impeded in any way. If the unit is
mounted in a different air pressure from where the air is being sampled (for example
an air duct), then a pipe must be taken from the exhaust port back to the same air
pressure zone as the sampling holes.
■
All signal cables must be screened and must be of a suitable type. The specific type
of cable will normally depend upon the local fire regulations.
■
The unit must not be placed in areas where either the temperature or humidity is
outside the specified operating range.
■
The unit should not be placed in close proximity to any equipment expected to
generate high Radio Frequency levels (such as radio alarms) or units generating high
levels of electrical energy (such as large electric motors or generators).
■
Ensure that when the detector is fitted to the wall there is enough space on the right
hand side to all allow removal and replacement of the filter element. (see section 10,
‘Maintenance).
5. Installation
5.1 General
NB ☞