ABB PQFM Instruction Manual page 216

Fault message
Overcurrent
RMS
Overcurrent
peak (SW)
Overvoltage
RMS
Preload
problem
216 Troubleshooting guide ç Manual Power Quality Filter PQFM
Cause
The system has detected RMS
overcurrent in the filter.
The software peak current
protection has been triggered.
The RMS value of the supply
voltage measured with the AC
voltage measurement board is
higher than the acceptable
maximum value.
The DC capacitors could not
be preloaded at startup. The
voltage increase on the DC
capacitors during the preload
phase is not high enough.
What to do
- Verify that the filter CTs are properly
installed and are not shorted.
- Verify that the unit current ratings and
order programmed at the
commissioning stage corresponds to
the rating and order physically present.
- Verify the filter cooling system and
check the IGBT temperature using the
PQF-Manager.
- Deactivate harmonic and reactive
power requirements and see if the
problem persists.
- Verify that the filter CTs are properly
installed and are not shorted.
- Verify that the unit current ratings and
order programmed at the
commissioning stage corresponds to
the rating and order physically present.
- Verify the filter cooling system and
check the IGBT temperature using the
PQF-Manager.
- Deactivate harmonic and reactive
power requirements and see if the
problem persists.
- Measure the three line voltages and
check if they are within limits.
- Measure the line voltages (e.g.
voltmeter) and compare them with the
line voltages given by the filter (PQF-
Manager or PQ-Link).
- Ensure that the AC voltage is properly
measured.
- Measure the three line voltages and
check if they are within limits.
- Verify the preload circuit and its
resistor R06.
- Inspect the DC-bus for traces of
damage that may have caused a short
circuit on the DC side of the IGBT
module or on the DC voltage
measurement board.