Troubleshooting:
•
Turn off the filter
•
Measure the resistance to ground of the LCL filter
components leads with a megohmmeter to check
for ground faults
•
Perform AC capacitors and current transducers
test (Section 6).
•
Check that the connectors on current transducers
and on the AFC card are pinned properly
•
Check AC capacitors current transducers cables
•
Replace the AFC card
•
Automatic switching between the grid and a
generator based on certain events can cause line
power loss leading to this alarm. Use auto reset if
this is the cause.
ALARM 306, Compensation limit
The compensation current exceeds unit capability. Unit is
running at full compensation.
Warning 306 is informational in nature, and does not
indicate a malfunction.
WARNING/ALARM 308, Resistor temp
Excessive resistor heatsink temperature detected.
A temperature feedback is implemented using an NTC
thermistor mounted on the damping resistor heatsink. The
temperature is calculated and compared to a power unit
dependent (PUD) alarm level.
Warning 308 is displayed when the PUD warning level is
reached. This indicates the resistor temperature is close to
the alarm level.
Troubleshooting:
Verify if:
•
Ambient temperature is too high
•
Incorrect clearance above and below the unit
•
Dirty heatsink
•
Blocked air flow around the unit
•
Damaged heatsink fan
WARNING/ALARM 309, Mains earth fault
A ground fault was detected, measured by the CT line
power currents.
The sum current from three line power CTs is too high.
The ground fault must be detected at every sample during
a period of 400ms, for Alarm 309 to be reported.
Troubleshooting:
Check the installation line power CTs and wiring
Replace the AFC card
ALARM 310, RTDC buffer full
Contact supplier.
ALARM 311, Switch freq. limit
The average switching frequency of the unit exceeded the
limit.
If the actual switching frequency exceeds 6 kHz for 10
electrical cycles, Alarm 311 is reported.
Service parameter P98-21 displays the actual switching
frequency. NOTE: Do not change any service parameters
unless directed to do so in this service manual.
Troubleshooting
Perform the Line Power Resonance Test ()
ALARM 312, CT range
Current transformer measurement limitation was detected.
Verify that the CTs used are of an appropriate ratio.
ALARM 314, Auto CT interrupt
Auto CT detection was interrupted by the user.
ALARM 315, Auto CT error
An error was detected while performing auto CT detection.
Auto CT detection does not work under the following
conditions: if any sum current transformers are installed,
when the active filter is supplied through a step up or step
down transformers, or when the filter is <10% of the CT
primary. Program the CT parameters manually if auto CT
detection fails.
WARNING 316, CT location error
The auto CT function could not determine the correct
locations of the CTs.
Program the CT parameters manually if auto CT detection
fails.
WARNING 317, CT polarity error
The auto CT function could not determine the correct
polarity of the CTs.
Program the CT parameters manually if auto CT detection
fails.
WARNING 318, CT ratio error
The auto CT function could not determine the correct
primary rating of the CTs.
Program the CT parameters manually if auto CT detection
fails.
Troubleshooting
VLT Active Filter AAF 00x
MG.90.V2.22 - VLT
®
is a registered Danfoss trademark
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