Installation and configuration
12
AutroSense Micra 10 Aspirating Smoke Detector Installers Handbook
Application
This detector is a smoke detector intended to provide localised incipient fire
detection. It is suitable for use in a wide range of applications, such as small non-
compartmentalised rooms, warehouse racking, or pieces of electronic or
electromechanical equipment where it is desirable to achieve individual incipient
fire reporting. In compartmentalised rooms, each compartment would normally
use individual aspirating detectors.
The detector employs a low-power aspirator (fan) designed to detect incipient
fires in relatively small areas. The detector is not intended to protect large areas,
or to sample from areas where there may be any difference in airflow rates or
pressure differentials. If detection in environments conforming to these
descriptions is required, other type detectors should be used.
System design
Simple designs with short sampling pipes produce the best results. Complex
sampling pipe runs should be avoided with the detector. The use of
T-branch pipes is not recommended. Maximum recommended sampling pipe
length is 50 m (
165 f
t.) in
still air
. If the protected area has airflow present, the
maximum permitted sampling pipe length will be reduced.
Note:
PipeCAD pipe modeling software must be used when designing a pipe
network and verifying its performance. Refer to the
PipeCAD System Design and
Installation User Guide
for complete instructions on how to design and install an
air sampling pipe network.
In order for the installation to conform to EN 54-20, pipes must conform at least
to EN61386
-1 Class 1131.
Sampling pipes must have capped ends. The end cap should be drilled with a
hole normally between 4 or 5 mm diameter and free from burrs. Sampling holes
should normally be 3 to 4 mm diameter or as calculated by PipeCAD, and free
from burrs. Each pipe run should not have more than 10 holes (including the end
cap hole). Pipe transit time from the furthest sampling hole from the detector
must not exceed 120 seconds and an approved type of pipe must be used. It is
strongly recommended that the smoke transit time from the furthest sampling
hole be checked during commissioning tests.
Capillary remote sampling points may be used in place of sampling holes.
Always locate the sampling points in positions to which smoke may reasonably
be expected to travel. It is usually better to locate the sampling pipe directly in the
airflow (for example, across the return air register of an air conditioning unit).
Note:
There is no substitute for carrying out smoke tests prior to installation of
pipework to indicate suitable sampling point location.
Summary of Contents for AutroSense Micra 10
Page 4: ...ii AutroSense Micra 10 Aspirating Smoke Detector Installers Handbook Glossary 45 Index 47...
Page 46: ...Troubleshooting 38 AutroSense Micra 10 Aspirating Smoke Detector Installers Handbook...
Page 52: ...Maintenance 44 AutroSense Micra 10 Aspirating Smoke Detector Installers Handbook...
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