Danfoss VLT AQUA Drive FC 202

Symptom Possible cause Test Solution
Open power
fuses
Phase-to-phase short. Motor or panel has a short phase-
to-phase. Check motor and panel
phases for shorts.
Eliminate any shorts detected.
Motor overload. Motor is overloaded for the appli-
cation.
Perform start-up test and verify that
motor current is within specifications. If
motor current is exceeding the name-
plate full load current, the motor can
run only with reduced load. Review the
specifications for the application.
Loose connections. Perform pre-start-up check for
loose connections.
Tighten loose connections.
Mains current
imbalance
greater than 3%
Problem with mains power
(see Alarm 4, Mains phase loss
description).
Rotate input power leads into the 1
position: A to B, B to C, C to A.
If imbalanced leg follows the wire, it is
a power problem. Check the mains
supply.
Problem with the AC drive. Rotate input power leads into the
AC drive 1 position: A to B, B to C, C
to A.
If the imbalanced leg stays on same in-
put terminal, it is a problem with the
AC drive. Contact the supplier.
Motor current
imbalance
greater than 3%
Problem with motor or motor
wiring.
Rotate output motor cables 1 posi-
tion: U to V, V to W, W to U.
If the imbalanced leg follows the wire,
the problem is in the motor or motor
wiring. Check motor and motor wiring.
Problem with AC drive. Rotate output motor cables 1 posi-
tion: U to V, V to W, W to U.
If the imbalanced leg stays on same
output terminal, it is a problem with
the unit. Contact the supplier.
AC drive accel-
eration prob-
lems
Motor data are entered incor-
rectly.
If warnings or alarms occur, refer to
the Warnings and Alarms section.
Check that motor data are entered
correctly.
Increase the ramp-up time in parame-
ter 3-41 Ramp 1 Ramp Up Time. Increase
current limit in parameter 4-18 Current
Limit. Increase torque limit in parame-
ter 4-16 Torque Limit Motor Mode.
AC drive decel-
eration prob-
lems
Motor data are entered incor-
rectly.
If warnings or alarms occur, refer to
the Warnings and Alarms section.
Check that motor data are entered
correctly.
Increase the ramp-down time in pa-
rameter 3-42 Ramp 1 Ramp Down Time.
Enable overvoltage control in parame-
ter 2-17 Over-voltage Control.
Maintenance, Diagnostics, and
Troubleshooting
Operating Guide | VLT® AQUA Drive FC 202
AQ262141056213en-000101 / 130R0882 | 159
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