ABB PQFM Instruction Manual page 221

Symptom
The filter is running
but it is unstable
(oscillating behavior).
The filter is running
with low load
indication and the
load harmonics are
not filtered.
When selecting a
harmonic, the filter
attempts to identify it
but after a while it is
put in standby. The
letter 'S' appears in
the harmonics
selection list. The
harmonic is not
filtered.
The 'ACK. FAULT'-
message is present on
the PQF-Manager. The
alarm contact
switches on after
some delay.
Cause / State
Two master units are fed
from the same CTs. The
setup guidelines for this
installation setup have
not been implemented.
The harmonics are not
selected, the curve
setting is very high or the
harmonics are put in
standby by the system.
The line currents
measured by the filter via
the CTs are lower than the
real load currents.
The filter is in standby-
mode, the IGBTs are not
switching.
The filter (CTs) is/are not
installed in a central
position and therefore
the filter does not
eliminate the harmonics
of all the loads.
The network conditions
do not allow for the
harmonic to be filtered at
present or there is a CT-
problem.
The filter has stopped due
to an error.
Manual Power Quality Filter PQFM ç Troubleshooting guide 221
What to do
Interconnect the units with an RJ-45
cable. If this is not possible:
- Select different harmonics on both
filters.
- If not possible, ensure that one
filter is operating in Mode 1 and
the other filter is operating in
Mode 3.
(Re)select the harmonics, check the
curve levels and ensure that the
correct settings are active
(Main/Auxiliary).
- Check the CT cabling for problems
(CT-installation, CT-shorts ...).
- Check the CT settings set up in the
PQF-Manager.
Check the standby mode settings to
ensure that they represent realistic
values.
Check that the CTs are installed at
the desired location.
- Check the CT-setup.
- Reselect the harmonic to see if the
problem persists.
- Leave the harmonic in standby.
The filter will automatically restart
identifying/filtering it when
another harmonic component is
successfully (re)identified.
- Acknowledge the fault to see a list
of most recent critical errors.
- Look in the filter event log for
more information on which errors
have occurred.
- Refer to the Table 53
for more information on these
errors and for guidelines on how to
troubleshoot them.
and Table 54