174 Operating instructions
Manual Power Quality Filter PQFS
9.7
Filter behavior on fault – retrieving error information
Under normal conditions the filter is either running or stopped and the PQF-item in the
PQF-Manager ‘Welcome’ screen shows the message ‘START’ or ’STOP’. In this case, if the
filter is stopped it can be started and if it is running it can be stopped. The start and stop
commands will be stored in the event log accessible in [/Welcome/PQF
Monitoring/Event logging].
All faults that occur are stored in the same event log. A fault can either be non-critical or
critical.
−
A non-critical fault is a transient fault (e.g. a voltage spike). When a non-critical fault
occurs the filter may stop the switching of the IGBTs momentarily (< 40 ms) but
they will automatically restart. The only way to pick up this type of fault is to analyse
the event log. Given the transient/random character of this type of fault, the filter
performance will hardly deteriorate when it occurs.
−
A critical fault is a fault that after occurrence cannot be successfully automatically
cleared by the system within a reasonable time. The time frame considered
depends on the error type. If the fault is considered critical by the system, the label
‘Critical’ will be shown in the event logging window. In addition, the PQF-item in the
PQF-Manager ‘Welcome’ screen will show the label ‘ACK. FAULT’. Note however that
if the fault disappears fast, this label disappears too. Depending on the type of
critical fault and the number of occurrences, the filter, when running, may either:
•
Stop (open the main contactor) and await user intervention. In this condition
the alarm contact of the PQF-Manager will switch on after a programmable
delay and the ‘Armed’ indicator will be OFF. The green LED on the main
controller board (Cf.
item 18, LED 2) will be off and the red LED on
(Cf.
item 18, LED 3). The user has to acknowledge the fault (with the
PQF-Manager via Modbus or PQ-Link or via remote control) before the filter
can be restarted.
By default, the ‘Armed’ indicator is associated with the fourth digital output
contact (cf.
) The digital output contact monitor at the
top of the PQF-Manager display (Cf.
the status of the digital output. Alternatively, the digital output considered
can be wired to monitor the ‘Armed’ indicator by distance (cf.
Section 6.12.4
).
•
Stop (open the main contactor) and restart automatically if the fault
disappears. If stopped, the alarm contact of the PQF-Manager will switch on
after a programmable delay and the ‘Armed’ indicator will be ON. The green
LED on the main controller board (Cf.
item 18, LED 2) will be ON and
item 18, LED 3). If it takes a long time
before the fault disappears, the user may decide to give a filter stop
command. This is done by highlighting the ‘PQF ACK. FAULT’ item in the
‘Welcome’ menu and selecting
. After this, the ‘Armed’ indicator will
be OFF. The green and red LED on the main controller board (Cf.
item 18, LEDs 2 and 3) will be OFF too.
