Quadnet Control Panel Engineering and Commissioning Manual
All devices up to that point will be operational, but devices beyond will not be active, as the control
panel will not initialise from Loop End 2 as it becomes very difficult to understand fully where the
problem lies.
The active faults list in Access level 2B (Supervisor) and Access Level 3 (Engineer) and will display
messages accordingly. These messages need to be viewed together as a complete set.
The control panel cannot determine the location of a short circuit, so a short circuit message will be
followed by the location of the open circuit which is created when the isolator in that device
responds to the short circuit.
Eg. Loop s/c and Loop o/c at device ‘X’
Thus in the Loop +ve to –ve short circuit example shown previously, the initialisation will reach
device 1 and fail thereafter. Thus the problem is after that point.
An investigation of the next device (device X+1) will determine if a correct loop voltage of
approximately 40V DC has reached that point. If this has happened then the problem lies in either
the connections at that point (device X+1) or a faulty electronics module (device X+1).
If the correct loop voltage of approximately 40V DC is not present at the next device (device X+1)
then stop the loop and investigate device X. The problem may be due to an incorrect connection, a
cable fault or a faulty electronics module.
If it is suspected that a device electronics module or device is faulty then try linking that device out
(link the +ve cores together) and reinitialising the loop. If the initialisation then passes that point the
device may be replaced. It is not advisable to leave a system with a device missing (positive cores
linked together) in this way as all successive devices will be displaced.
The loop must be re-initialised to clear this fault.
Please note: A short circuit between cores with a value of between 3K and 300 ohm can cause
corruption of the data on the loop and although no Short Circuit fault is reported the system integrity
will be compromised.
Loop –ve Open Circuit
If the system faces a Loop –ve open circuit during initialisation, the initialisation will not fail at that
point, but continue as normal to the end of the loop. All devices will be operational (as long as no
other faults exist).
A message of Addressable circuit: -ve open circuit will be displayed, but the control panel
cannot detect where the open circuit fault is located.
In order to locate the fault position, stop the loop, disconnect Loop end 2, wait at least 3 minutes
and then
reinitialise the system. The initialisation will fail at that point and a message of Loop not
complete will be displayed.
Thus in this Loop –ve open circuit example, the initialisation will reach device X+1 and fail there.
Thus the problem is after that point.
An investigation of the next device (device X+2) will determine if a correct loop voltage of
approximately 40V DC has reached that point. If this has happened then the problem lies in either
the connections at that point (device X+2) or a faulty electronics module (device X+2).
If the correct loop voltage of approximately 40V DC is not present at the next device (device X+2)
then stop the loop and investigate device X+1. The problem may be incorrect connection, a cable
fault or a faulty electronics module.
If it is suspected that a device electronics module is faulty then try linking that device out (link the
+ve cores together) and reinitialising the loop. If the initialisation then passes that point the device
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