Alarm (Sounder circuits)
To comply with the requirements
of
BS 5839: Part 1:2002 +
A2:2008, two or more alarm
sounder circuits should be used
on all installations.
NOTE:
All sounder circuits
(sectors) will operate together in
the event of a fire condition.
NOTE:
Each sounder output is
0.5A maximum protected by
0.75A fuse.
1 & 2 Zone
Panels
4 & 8 Zone
Panels
1A maximum
Alarm sounder
load per panel
1.5A maximum
Alarm sounder
load per panel
The load must be shared between
the sounder circuits. The alarm
sounder circuits are regularly
pulse monitored for failure. It is
important that the last alarm
sounder is fitted with a
10K Ohm
end-of-line resistor.
The sounder outputs are
monitored in alarm for loss of
supply or multiple sounder output
overloads
Where a sounder circuit is not
being used, the
end-of-line resistor
must be fitted across its terminals
in the control panel.
Class Change
A pair of unmonitored terminals
allow only the system alarm
sounders to be activated from a
remote position. It is considered that
the major use for these will be for
class change functions in schools
and colleges.
Auxiliary Contacts
These are normally open (NO) and
normally closed (NC) contacts that
change over when the panel goes
into a fire condition. The contacts
are rated at 24V dc 1A for a
resistive load and should not be
used to switch voltages in excess of
50V. The auxiliary circuits should be
powered from an independent
power supply.
NOTE:There is no
indication given at the
panel of class change push
button operation.
Fire Panels
System design
4188-424 issue 4_Part 1_10-09
3
NOTE:
Spur wiring is not permitted
off
circuits.
alarm sounder
Sounder
Sounder
Control panel
Alarm sounders
be polarised
and suppressed.
must
S1+
Sn+
S1-
Sn-
Alarm sounder
must have a
series blocking
diode
Sounder circuit that is
not used is terminated
with an end-of line resistor
ALARM SOUNDER CIRCUIT
End of line Resistor
10k Ohms
Control panel
Sn+
Sn-
Earth
continuity
Sounder
Figure 3 Alarm sounder circuit used and unused
Class change
100m max.
Cable
distance
Push button switch
or relay pulsed
at 1 second
interval (minimum)
for class change
application
CC1
C 2
C
Control panel
Figure 4 Class change circuit
Contacts rated 1A@24Vdc
Contacts
change
over occur
with a fire
condition
NC
NC
N0
N0
Auxiliary
contacts
Control panel
100m maximum
cable distance
Figure 5 Auxiliary contacts