Danfoss VLT AutomationDrive FC 301 Operating Instructions Manual page 51

Maintenance, Diagnostics, a...
Symptom Possible cause
Phase-to-phase short.
Open power
fuses or
Motor overload.
circuit
breaker trip
Loose connections.
Problem with mains power (see
Alarm 4, Mains phase loss
Mains current
description).
imbalance
greater than Problem with the frequency
3%
converter.
Problem with motor or motor
Motor current
wiring.
imbalance
greater than
Problem with frequency
3%
converter.
Frequency
converter Motor data are entered
acceleration incorrectly.
problems
Frequency
converter Motor data are entered
deceleration incorrectly.
problems
Table 7.5 Troubleshooting
MG33AQ02
Operating Instructions
Test
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 frequency
converter 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 7.4 List of Warnings and Alarms
Check that motor data are entered correctly.
If warnings or alarms occur, see
chapter 7.4 List of Warnings and Alarms
Check that motor data are entered correctly.
Danfoss A/S © 07/2015 All rights reserved.
Solution
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 may 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 imbalance leg stays on same input
terminal, it is a problem with the
frequency converter. Contact supplier.
If imbalanced leg follows the wire, the
problem is in the motor or motor wiring.
Check motor and motor wiring.
If imbalance 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.
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