Common Fire and fault
The
common fire
output is a
normally open electronic switch
that closes with a fire condition.
The
common fault
output is a
normally closed electronic switch,
which opens with a fault condition,
this is for a fail safe operation.
Each electronic switch is current
limited, see specification.
Use a relay to provide volt free
contacts.
The +24V & 0V is a power supply
for use with auxiliary contacts,
common fire and common fault
circuits, see specification.
Repeat Panel
A Repeat panel can be connected
in series to the control panel. A
repeat panel duplicates fire and
fault indications together with
system controls.
Cables
Fire Panels
4
4188-424 issue 4_Part 1_10-09
24+
CFT
CFR
0V
Control panel
Current limited
Current limited
Normally closed
electronic switch
Normally open
electronic switch
NOTE: The maximum 24V
relay load is 280mW (Common
Fire) and 500mW (Common Fault).
Use a relay to
provide volt free contacts.
0V
24V+ - 24V+ supply
CFT
- Common fault
CFR
- Common fire
0V
- 0V supply
The Indicator and Relay
shown connected here
are typical examples
of external circuit
Figure 6 Fire
fault & 24V
outputs
Length per circuit
Type of circuit
Recommended cables, also see BS5839:Part 1 guidance
2m
Mains power supply cord
see power supply cord
1Km
Zone circuit
See BS5839:Part 1:2002 + A2:2008 for guidance
1Km
Sounder circuits
100m
Auxiliary circuit
100m
Common fire and fault circuit
100m
Class change circuit
500m total circuit
Repeat panel link
Belden type -screened 2-core twisted pair
Cables
The guidance of
BS5839:Part 1:2002 + A2:2008,
should be followed.
Generally available electrical
installation cable may be used,
providing the cable is:
q
to
BS6387
q
with no more than
2 - cores
q
each core having no less than
1.5mm
2
cross section area
(maximum
2.5mm
2
).
q
with an inherent or through
metal conduit screen for earth
continuity in order to produce
electrical protection and
screening.
q
having protection from heat and
mechanical damage.
Power supply cord
The mains supply to the panel
should be wired in
0.75mm
2
cable
with a effective connection to
building service earth continuity
conductor.
R+ R-
Control panel
Repeat panel
Screen must be
connected to panel
R+ R-
Figure 7 Control
to repeat panel
connections