Danfoss VLT Ea4, Operating Manual

Page: 66 / 76

Symptom Possible cause Test Solution
Motor speed
unstable Possible incorrect parameter
settings. Check the settings of all motor pa-
rameters, including all motor com-
pensation settings. For closed-loop
operation, check PID settings.
Check settings in parameter group 1-6*
Load Depen. Setting . For closed-loop
operation, check settings in parameter
group 20-0* Feedback .
Motor runs
rough Possible overmagnetization. Check for incorrect motor settings
in all motor parameters. Check motor settings in parameter
groups 1-2* Motor data , 1-3* Adv Motor
Data , and 1-5* Load Indep. Setting .
Motor does not
brake Possible incorrect settings in
the brake parameters. Ramp-
down times may be too short. Check brake parameters. Check
ramp time settings. Check parameter groups 2-0* DC Brake
and 3-0* Reference Limits .
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
nameplate full load current, the motor
can run only with reduced load. Re-
view the specifications for the applica-
tion.
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
AC drive 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 . In-
crease current limit in parameter 4-18
Current Limit . Increase torque limit in
parameter 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 .
6.11 Maintenance and Service
To prevent breakdown, danger, and damage, examine the drive for loose terminal connections, excessive dust buildup, and worn
parts at regular intervals. Replace worn or damaged parts with Danfoss authorized parts. For service and support, contact the local
Danfoss supplier.
AQ434333248451en-000101 / 130R1286 66 | Danfoss A/S © 2023.01
Operating the Drive
VLT Ea4 Parallel Drive Modules
Operating Guide