Fault Messages - Danfoss VLT 3000 Series Product Manual

Fault messages

140
Fault messages
Inverter fault
®
The VLT power section is defective.
Overvoltage
The voltage of the VLT ® frequency conver-
ter's intermediate circuit (DC-voltage) is too
high. Possible reasons: line voltage too
high, transients on the line voltage, or re-
generative motor operation.
Note: When the VLT ® frequency converter
is stopped, repeated transients are charg-
ing the intermediate circuit, as it supplies no
power to the motor.
• If the fault indication is given when
the speed is reduced, you can increase
the ramp-down time. If this is not
possible, the application may require a
VLT ®
frequency converter with brake.
If the fault indication is given in other
situations, the problem will be due to
the mains supply.
Undervoltage
®
The voltage of the VLT frequency conver-
ter's intermediate circuit (DC-voltage) is too
low. Possible reasons: line voltage too low
or defect in the VLT ® frequency converter's
charging circuit/rectifier.
• Check whether the line voltage is OK.
Overcurrent
The peak current limit of the inverter has
been reached. This may be due to a short-
circuit in the output of the VLT
converter.
• Check the motor and the motor cable
for ground failure.
Ground fault
Ground failure on the VLT
verter output. Another reason might be that
the motor cable is too long.
• Consult the data sheets for permitted
cable length.
Check the motor and the motor cable
for earth leakage.
®
MG.30.A7.02 - VLT is a registered Danfoss trademark
Over-temp
The temperature inside the VLT
converter is too high. Possible reasons:
the ambient temperature is too high (max.
40/45 °C), the VLT
cooling ribs are covered, or the VLT
quency converter's fan is defective.
• Reduce the ambient temperature by
increasing the ventilation.
Uncover/clean the cooling ribs.
Replace the fan.
Overload
The electronic VLT
This means that the motor has consumed
more than 105% of rated VLT
converter current for too long.
• Reduce the motor load. If this is not
possible the application may require a
larger VLT
Motor trip
The electronic motor protection is active.
This means that the current consumed by
the motor at low speed has been too high
for too long.
• The motor has been loaded
excessively at low speed.
If the load cannot be changed,
you must exchange the motor for
a bigger one, or provide extra cooling
of the existing motor.
If so, the electronic motor protection
can be de-activated in parameter 315.
®
frequency
® frequency con-
®
frequency
®
frequency converter's
® fre-
® protection is active.
®
frequency
® frequency converter.