Danfoss VLT Refrigeration Drive FC 103 Operating Instructions Manual page 43

Maintenance, Diagnostics an...
Symptom Possible cause
Possible incorrect parameter
Motor speed settings
unstable
Possible over-magnetisation
Motor runs
rough
Possible incorrect settings in
Motor will not
the brake parameters. Possible
brake
too short ramp-down times
Phase to phase short
Motor overload
Open power
fuses or 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
wiring
Motor current
imbalance
greater than
Problem with the frequency
3%
converters
Motor data are entered
Frequency incorrectly
converter
acceleration
problems
Frequency Motor data are entered
converter incorrectly
deceleration
problems
Acoustic noise
or vibration
(e.g. a fan
blade is Resonances, e.g. in the
making noise motor/fan system
or vibrations
at certain
frequencies)
Table 7.5 Troubleshooting
MG16E302
Operating Instructions
Test
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-startup check for loose
connections
Rotate input power leads into the
frequency converter 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 leads 1 position: U to
V, V to W, W to U.
Rotate output motor leads 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
Bypass critical frequencies by using
parameters in parameter group 4-6* Speed
Bypass.
Turn off over-modulation in 14-03 Overmo-
dulation.
Change switching pattern and frequency in
parameter group 14-0* Inverter Switching.
Increase Resonance Dampening in
1-64 Resonance Dampening.
Danfoss A/S © Rev. 2014-02-06 All rights reserved.
Solution
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 group 2-0* DC Brake and
3-0* Reference Limits.
Eliminate any short circuits detected.
Perform startup 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 mains power
supply.
If imbalance leg stays on same input
terminal, it is a problem with the unit.
Contact the 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 the supplier.
Increase the ramp-up time in 3-41 Ramp 1
Ramp Up Time. Increase ramp 3-80 Jog and
3-82 Starting 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.
Check if noise and/or vibration have been
reduced to an acceptable limit.
7 7
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