Common Problems And Solutions; Chapter 7 Troubleshooting And Fault Information - Delta VFD-L series User Manual

CHAPTER 7 Troubleshooting and Fault Information

The VFD-L AC drive has a comprehensive fault diagnostic system that includes
several different alarms and fault messages.
corresponding protective functions will be activated. The following faults are
displayed on the AC drive digital keypad. The six most recent faults can be
read on the digital keypad display by viewing Pr.6-07 to Pr.6-12.
NOTE: Faults can be cleared by a reset from the keypad or Input Terminal.

Common Problems and Solutions:

Fault
Fault Descriptions
Name
The AC drive detects an
abnormal increase in
current.
The AC drive detects
that the DC bus voltage
has exceeded its
maximum allowable
value.
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Once a fault is detected, the
Corrective Actions
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.
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.
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.
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VFD-L Series
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