Quadnet Control Panel Engineering and Commissioning Manual
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may be replaced. It is not advisable to leave a system with a device missing (positive cores linked
together) in this way as all future points will be displaced.
The loop must be re-initialised to clear this fault. Always wait at least 3 minutes between stopping a
loop and reinitialising.
Device Faults
If the system detects a
device fault or fire activation
during initialisation, the initialisation will not
fail at that point. All devices will be operational (as long as no other faults exist).
However, the system can only ignore a certain amount of fire or fault data until initialisation is
complete, and beyond certain limits initialisation will fail and the various fault or fire activations will
be displayed.
In either case, the event generated should be dealt with before the loop is reinitialised.
Firstly, investigate and rectify any fire activations which are displayed. These may vary from Manual
Call Points which have not been reset, to Multipoint detectors which are contaminated.
Secondly, investigate and rectify any fault conditions which are displayed. These may vary from
‘Input open circuit’, to a Multipoint detector with its optical chamber loose (indicating signal low).
The system may then be reinitialised and commissioned as required.
Earth Faults
General
If the control panel detects a short circuit to earth/screen from one of its supply rails (either 0v or
+ve) an
Earth Fault
will be displayed.
Remove the circuit cables connected to the control panel one at a time and reset the system. When
the circuit with the earth fault is disconnected, the earth fault will clear within approximately 30
seconds of being reset.
Note that if a computer is connected to the control panel, an earth fault may be generated at the
control panel. If the connection is permanent, an optical isolator must be used between the PC and
the control panel.
A short circuit (low resistance: expected to be less than 5R) may be identified and tracked with an
electronic test meter between either the positive core or the negative core and the screen of that
circuit.
It is not possible to override the earth fault monitoring as it is important for correct system operation.
If it is shown that the earth fault is on the addressable device loop, then disconnect it from the
control panel and investigate it with an electronic test meter.
Loop –ve to Screen
If the fault is a
short circuit from screen to loop –ve
then it will be easily identified and rectified
with an electronic test meter.
An investigation of the resistance reading between loop –ve and earth/screen at the control panel
for each end of the addressable device circuit should give a good indication of the location of the
short circuit.
