Loop Circuit Connections
The fire alarm system can permit significant reductions in installation costs
when compared with conventional and other multi-state systems. This is
because of the ability to wire a large number of devices (outstations), like
sensors, sounders, manual call points, interface units and repeat panels
on one loop circuit.
Loop Capacity
NOTE: It is important that redundancy is built into the system to
accommodate future expansions.
Devices (Outstations) per loop
The number of devices (outstations) on one loop circuit can be limited by
the total number of addresses available, the electrical load on the circuit, the
maximum cable length and other geographical considerations.
A maximum of 200 devices are allowed per loop circuit:
As a general rule allow 1000 load factor per loop circuit.
Code and device
Load factor
Maximum
for each
of each
device
device
per loop
78400-02, 78400-03 Alarm sounder
25
40
78277-01NM Repeat Sounder
8
125
78301-01NM Mains powered interface
3
8
78321-01NM Loop powered interface
2
30
78310-01NM Loop powerered Zone Module
25
40
78315-01NM Single Channel Interface
10
100
78299-02 or 78299-03
Slave LED or Relay unit
1
50‡
78299-01 Tee breaker
1
200
78215-01 or 78220-01 or 78230-01
Optical, Heat or Ionisation sensor
1
200
78260-01 Duct Sensor (also needs a Slave LED) 1
50‡
78275-01 Optical Sensor Sounder
8
125
78285-01NM Heat Sounder
8
125
78150 or 78155 Manual call point
1
200
78600-01 Repeat Panels
3
32
‡
Installations prior to March 1996 have a maximum of 10 slave devices.
Loop Circuit Connections
Loop Capacity
78910-03NM Issue 2_10/96
5-1
Senator II Installation Manual