Page 9 of 16 Revision 2.1 May 2019
Alarmline II Analogue Installation Manual
There are many applications which Linear Heat Detection cable is used
to provide protection for.
The linear heat detection cable should be adequately supported to
prevent sagging. Ideally cable supports should be placed every 1m (3ft)
and no more than 1.5m (5ft) apart. It may be necessary to place more
supports around corners and other transition areas.
Care should be taken when mounting the cable in clips (or equivalent)
that they are not done so tight as to crush the cable. The detection cable
should be held rmly without deformation. Avoid placing excessive
tension in the cable, no greater than 50N. Ensure also that the minimum
bend radius is observed at all times – 50mm (2").
It is of particular importance to use a silicone pad insulator between the
heat sensing cable and the xing clip if the metal clip is exposed to the
sun or attached to a piece of equipment which may get hot and transfer
the heat to the cable.
Where possible, it is preferable to install the linear heat detection cable in
one continuous run of cable with as few splices as possible.
When pulling the detection cable from a reel, a reel stand must be used.
Do not pull the cable o the reel vertically with the reel stationary as this
will twist and damage the cable. A guide wire may be required for
installations where supporting the cable at the recommended spacing is
not practical. Ensure the diameter or gauge of the guide wire is adequate
for the distance which is being spanned. Commerically available stainless
steel wire with a diameter of approximately 2mm is suitable for use as a
guide wire.
Connections into junction boxes and other enclosures must use strain
relief connectors which provide dust and moisture protection (IP65 or
greater protection). The standard diameter of detection cable is 4.5mm
(0.177") to 6.05mm (0.238") Suitable cable glands are shown below which
t an M16 standard knockout.
Installation Hardware
Alarmline II Analogue Linear Heat Detection cable is suitable for use in
ambients down to -40°C (-40°F). Such conditions occur in cold storage
freezer warehouses and outdoors for example.
When installing LHD cable in low ambients or for use in low temperature
conditions careful consideration of the conditions and environment
should be undertaken.
If possible, do not install the LHD cable when the ambient temperature
is below -10°C (-14°F). The materials within the cable will become less
exible and are more prone to damage. If the ambient temperature is
likely to drop signicantly after installing the cable take into account
linear shrinkage of the cable when attaching support brackets. The cable
can shrink in length by 12% at -40°C (-40°F).
A silicone pad insulator should be placed around the cable before
clipping into the support bracket. This prevents damage to the cable
and reduces the heat sink eect of the clip.
The minimum bend radius of the detection cable should be increased
to 100mm (4") to account for the reduced exibility. The maximum
distance between support brackets should be no more than 1m (3ft)
and it is important to support the cable close to either side of any bend.
Ensure any junction boxes other enclosures are waterproof and suitable
for the expected operating temperatures.
Low Temperature Installation Considerations
Figure 4: Typical Cable Glands for connection of Linear Heat Detection cable
into an enclosure
