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Troubleshooting
Fault Codes
The SIMVFD 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 fault codes are then displayed on
the digital keypad display.
NOTE: Faults can be cleared by a reset from the keypad or input terminal.
Fault Name Fault Description
Corrective Actions
oc The drive detects an abnormal
increase in current.
1. Check whether the motor’s horsepower corresponds to the
drive output power.
2. Check the wiring connections between the drive and motor
for possible short circuits.
3. Increase the Acceleration time (1-1).
4. Check for possible excessive loading conditions at the motor.
5. If there are any abnormal conditions when operating the
drive after short-circuit is removed, the drive should be sent
back to the manufacturer.
ou The drive detects that the DC
bus voltage has exceeded its
maximum allowable value.
1. Check whether the input voltage falls within the rated drive
input voltage.
2. Check for possible voltage transients.
3. Bus over-voltage may also be caused by motor regeneration.
Increase the deceleration time.
4. Check whether the required braking power is within the
specified limits.
oH The 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 heat sinks and check for
possible dirty heat sink fins.
4. Provide enough spacing for adequate ventilation.
Lu The drive detects that the DC
bus voltage has fallen below its
minimum value.
Check whether the input voltage falls within the drive’s rated
input voltage.
oL The drive detects excessive drive
output current.
Note:
The drive can withstand up
to 150% of the rated current for a
maximum of 60 seconds.
1. Check whether the motor is overloaded.
2. Increase the drive’s output capacity.
