CIE-A-200 Control Panel Engineering and Commissioning Manual
55
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 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 circui
t’, to a Multipoint detector with its optical chamber loose (indicating signal low).
The system may then be reinitialised and commissioned as required.
It is important that devices (or chambers in earlier devices) are removed/replaced only with
the loop stopped.
