Danfoss VLT AutomationDrive FC 301 Instruction Manual page 52

Diagnostics and Troubleshoo...
Symptom
Motor is not
reaching
maximum
speed
Motor speed
unstable
Motor runs
rough
Motor will
7 7
not brake
Open power
fuses or
circuit
breaker trip
Line power
current
imbalance
greater than
3%
Motor current
imbalance
greater than
3%
Adjustable
frequency
drive
acceleration
problems
Adjustable
frequency
drive
deceleration
problems
Table 7.7 Troubleshooting
50
Possible Cause
Frequency limits set wrong
Reference input signal not
scaled correctly
Possible incorrect parameter
settings
Possible over-magnetization
Possible incorrect settings in
the brake parameters. Possible
too short ramp-down times.
Phase-to-phase short
Motor overload
Loose connections
Problem with line power (See
Alarm 4 Line phase loss
description)
Problem with the adjustable
frequency drive unit
Problem with motor or motor
wiring
Problem with adjustable
frequency drive unit
Motor data are entered
incorrectly
Motor data are entered
incorrectly
Danfoss A/S © Rev. 2014-02-10 All rights reserved.
Instruction Manual
Test
Check output limits in4-13 Motor Speed High
Limit [RPM], 4-14 Motor Speed High Limit [Hz],
and 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 phase for shorts.
Motor is overloaded for the application.
Perform pre-start-up check for loose
connections.
Rotate input power leads into the drive one
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
Check that motor data are entered correctly
If warnings or alarms occur, see
Check that motor data are entered correctly
Solution
Program correct limits.
Program correct settings.
Check settings in parameter group 1-6*
Load-Depend.Setta. 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 group 2-0* DC Brake and
3-0* Reference Limits.
Eliminate any shorts detected.
Perform start-up test and verify motor
current is within specifications. If motor
current is exceeding nameplate full load
current, motor may run only with reduced
load. Review the specifications for the
application.
Tighten loose connections.
If imbalanced leg follows the wire, it is a
power problem. Check line power supply.
If imbalance leg stays on same input
terminal, it is a problem with the unit.
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 3-41 Ramp 1
Ramp-up Time. Increase current limit in
4-18 Current Limit. Increase torque limit in
4-16 Torque Limit Motor Mode.
Increase the ramp-down time in
3-42 Ramp 1 Ramp-down Time. Enable
overvoltage control in 2-17 Over-voltage
Control.
MG33AN22