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CHAPTER 7 TROUBLESHOOTING AND FAULT INFORMATION
The L2500 AC drive has a comprehensive fault diagnostic system that includes several
different alarms and fault messages. Once a fault is detected, the corresponding protective
functions will be activated. The following faults are displayed as shown on the AC drive
digital keypad panel. The three most recent faults can be read on the digital keypad
display by viewing Pr.6-08 to Pr.6-10.
NOTE: faults can be cleared by a reset from the keypad or Input Terminal.
Common Problems and Solutions:
Fault Name
Fault Descriptions
Corrective Actions
The AC drive detects an
abnormal increase in
current.
1. Check whether the motors horsepower
corresponds to the AC drive output power.
2. Check the wiring connections between the
AC drive and motor for possible short
circuits.
3. Increase the Acceleration time (Pr.1-09,
Pr.1-11).
4. Check for possible excessive loading
conditions at the motor.
5. If there are any abnormal conditions when
operating the AC drive after short-circuit
being removed, it should be sent back to
manufacturer.
The AC drive detects that
the DC bus voltage has
exceeded its maximum
allowable value.
1. Check whether the input voltage falls within
the rated AC drive input voltage.
2. Check for possible voltage transients.
3. Bus over-voltage may also be caused by
motor regeneration. Either increase the
decel time or add an optional braking
resistor.
4. Check whether the required braking power is
within the specified limits.
The AC drive temperature
sensor detects excessive
heat.
1. Ensure that the ambient temperature falls
within the specified temperature range.
2. Make sure that the ventilation holes are not
obstructed.
3. Remove any foreign objects on the heatsinks
and check for possible dirty heat-sink fins.
4. Provide enough spacing for adequate
ventilation.
The AC drive detects that
the DC bus voltage has
fallen below its minimum
value.
Check whether the input voltage falls within the
rated AC drive’s input voltage.