Danfoss VLT AutomationDrive FC 302 Operating Manual page 72

Maintenance, Diagnostics, a...
Symptom
Motor is not
reaching
maximum
speed
Motor speed
unstable
Motor runs
rough
Motor does
not brake
Open power
fuses
8 8
Mains current
imbalance
greater than
3%
Motor current
imbalance
greater than
3%
AC drive
acceleration
problems
AC drive
deceleration
problems
Table 8.5 Troubleshooting
70
Possible cause
Frequency limits set wrong.
Reference input signal not
scaled correctly.
Possible incorrect parameter
settings.
Possible overmagnetization.
Possible incorrect settings in
the brake parameters. Ramp-
down times may be too short.
Phase-to-phase short.
Motor overload.
Loose connections.
Problem with mains power (see
alarm 4, Mains phase loss
description).
Problem with the AC drive.
Problem with motor or motor
wiring.
Problem with AC drive.
Motor data are entered
incorrectly.
Motor data are entered
incorrectly.
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VLT® AutomationDrive FC 302
Test
Check output limits in parameter 4-13 Motor
Speed High Limit [RPM], parameter 4-14 Motor
Speed High Limit [Hz], and parameter 4-19 Max
Output Frequency
Check reference input signal scaling in
parameter group 6-0* Analog I/O mode and
parameter group 3-1* References.
Check the settings of all motor parameters,
including all motor compensation settings.
For closed-loop operation, check PID settings.
Check for incorrect motor settings in all
motor parameters.
Check brake parameters. Check ramp time
settings.
Motor or panel has a short phase-to-phase.
Check motor and panel phases for shorts.
Motor is overloaded for the application.
Perform pre-start-up check for loose
connections.
Rotate input power leads into the 1 position:
A to B, B to C, C to A.
Rotate input power leads into the AC 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.
If warnings or alarms occur, see
chapter 8.5 List of Warnings and Alarms.
Check that motor data are entered correctly.
If warnings or alarms occur, see
chapter 8.5 List of Warnings and Alarms.
Check that motor data are entered correctly.
Solution
Program correct limits.
Program correct settings.
Check settings in parameter group 1-6*
Load Depen. Setting. For closed-loop
operation, check settings in parameter
group 20-0* Feedback.
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 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. Review the specifi-
cations for the application.
Tighten loose connections.
If imbalanced leg follows the wire, it is a
power problem. Check the mains supply.
If the imbalanced leg stays on same input
terminal, it is a problem with the AC
drive. Contact 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 supplier.
Increase the ramp-up time in
parameter 3-41 Ramp 1 Ramp Up Time.
Increase current limit in
parameter 4-18 Current Limit. Increase
torque limit in parameter 4-16 Torque Limit
Motor Mode.
Increase the ramp-down time in
parameter 3-42 Ramp 1 Ramp Down Time.
Enable overvoltage control in
parameter 2-17 Over-voltage Control.
MG38A202