INSTALLING BEAM DETECTORS
Installation of interface
The interface should be positioned so that it is easily
accessible and such that the cable connecting the
interface to the receiver is not more than 100m long.
The use of multi-core cable for connecting two or more
receivers is not permitted. Care should be taken that
this cable is routed away from building electrical cables
–
+
}
Loop +ve
}
Loop –ve
+
remote
–
fire LED
rear view
XP95/Discovery
Loop
NOTE: The beam detector is polarity sensitive.
Fig 3 Interface wiring diagram
and any switchgear. Ensure that the cable used has
adequate mechanical protection.
Connect cables as shown in Fig 3 and set the ad-
dress at the DIL switch on the front of the interface as
described opposite.
Issue No
Fig 4 Front view of interface
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Setting the obscuration level
Set the interface to one of the four obscuration settings
shown below.
From receiver
Maximum cable
length 100m
A
B
C
D
Setting the 'total obscuration' signal
Total obscuration is defi ned as obscuration of the beam
Colour
Terminal
Red
A
to greater than 93% in 8–10 seconds. The interface
Black
B
Yellow
C
must be set so that either a 'fi re' or a 'fault' signal is
Blue
D
generated when this occurs. This is done by moving
segment 3 of the sensitivity switch (Fig 4) to '0' for
a 'fault' signal or to '1' for a 'fi re' signal. The factory
default setting is 'fault'.
6
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Obscuration level in %
25
Offi ces, small premises,
non-smoking clean areas,
eg, museums, theatres
35
Factories, warehouses
50
Hostile environments, eg,
mills, foundries
65
Retro mode operation
only
Table 1 Obscuration levels
Typical application