Danfoss VLT AutomationDrive FC 302 Instruction Manual page 63

Maintenance, Diagnostics an...
Symptom Possible cause
Phase-to-phase short.
Open power
fuses or
Motor overload.
circuit
breaker trip
Loose connections.
Problem with line power (see
Line power Alarm 4 Mains phase loss
description).
current
imbalance Problem with the adjustable
greater than frequency drive.
3%
Problem with motor or motor
Motor current
wiring.
imbalance
greater than
Problem with adjustable
3%
frequency drive.
Adjustable
frequency
Motor data are entered
drive
incorrectly.
acceleration
problems
Adjustable
frequency
Motor data are entered
drive
incorrectly.
deceleration
problems
Table 7.5 Troubleshooting
MG34U422
Instruction Manual
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 adjustable
frequency drive one position: A to B, B to C,
C to A.
Rotate output motor leads one position: U to
V, V to W, W to U.
Rotate output motor leads one position: U to
V, V to W, W to U.
If warnings or alarms occur, see
chapter 7.5 List of Warnings and Alarms.
Check that motor data are entered correctly.
If warnings or alarms occur, see
chapter 7.5 List of Warnings and Alarms.
Check that motor data are entered correctly.
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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 line power
supply.
If the imbalanced leg stays on same input
terminal, it is a problem with the
adjustable frequency 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.
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