Danfoss VLT FC 280 Operating Manual page 123

Operating Guide | VLT® Midi Drive FC 280
Table 61: Troubleshooting
(continued)
Symptom
Motor speed is unstable
Motor runs roughly
Motor does not brake
Open power fuses or circuit
breaker trip
Mains current imbalance
greater than 3%
Motor current imbalance
greater than 3%
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Possible cause
Possible incorrect parameter
settings
Possible overmagnetization
Possible incorrect settings in
the brake parameters. Possible
too short ramp-down times.
Phase-to-phase short
Motor overload
Loose connections
Problem with mains power
(see Alarm 4, Mains phase loss
description)
Problem with the drive unit
Problem with motor or motor
wiring
Problem with the drive unit
Maintenance, Diagnostics, and Troubleshooting
Test
Check the settings of all motor
parameters, including all mo-
tor compensation settings. For
closed-loop operation, check
PID settings.
Check for incorrect motor set-
tings in all motor parameters.
Check brake parameters.
Check ramp time settings.
Motor or panel has a short
phase-to-phase. Check motor
and panel phase for shorts.
Motor is overloaded for the ap-
plication.
Perform pre-start-up check for
loose connections.
Rotate input power leads into
the drive 1 position: A to B, B
to C, C to A.
Rotate input power leads into
the drive 1 position: A to B, B
to C, C to A.
Rotate output motor cables 1
position: U to V, V to W, W to U.
Rotate output motor cables 1
position: U to V, V to W, W to U.
AQ381425076031en-000201 / 130R1223 |
Solution
Check settings in parameter
group 6-** Analog I/O Mode.
Check motor settings in
parameter groups 1-2* Motor
data, 1-3* Adv motor data, and
1-5* Load indep. setting.
Check parameter groups 2-0*
DC brake and 3-0* Reference
limits.
Eliminate any shorts detected.
Perform the start-up test and
verify that motor current is
within specifications. If mo-
tor current is exceeding name-
plate full load current, the mo-
tor may run only with reduced
load. Review the specifications
for the application.
Tighten loose connections.
If the imbalanced leg follows
the wire, it is a power problem.
Check mains supply.
If the imbalanced leg stays
on same input terminal, it is a
problem with the unit. Contact
the supplier.
If the imbalanced leg follows
the wire, the problem is in the
motor or motor wiring. Check
motor and motor wiring.
If the imbalanced leg stays on
same output terminal, it is a
problem with the unit. Contact
the supplier.
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