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Device loop circuits
Device loop circuits
Each loop circuit can each accept the connection of addressable devices / outstations,
up to 200 maximum per circuit. To maintain earth continuity on a loop, the loop cable
screen must be continued through each system device, whether the earth is connected
to a device or not.
A loop circuit must not cover more than 10,000m
2
of
fl
oor area of a
protected site.
A spur circuit must always be taken from the “line common”
terminals of a 3 ways device.
A spur must not cover more than the equivalent of one zone as
de
fi
ned in BS 5839 Part 1.
As every loop device has an isolator
fi
tted, it is not necessary
to apply special attention where there are more than 32 devices.
However no more than a maximum of 512
fi
re detectors and/or
manual call points shall be installed on one control panel.
L1
01
L2
02
Manual call point
0V
C
L1
0V
3
4
IN
1
OU
T
2
L2
L2
02
S device
(2-way)
3
01
L1
02
L2
01
L1
PANEL
S-Quad
S device
(2-way)
3
Earth to
metal box
LOOP CIRCUIT 1
L1 0V L2 0V
LOOP n
IN4
OUT5
C3
S-Quad
IN4
OUT5
C3
Terminal Card
