Danfoss VLT HVAC Drive FC 102 Instruction Manual page 50

Diagnostics and Troubleshoo...
Symptom
Motor is not
reaching
maximum
speed
Motor speed
unstable
Motor runs
rough
Motor will not
7 7
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
46
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. Possible
too short ramp-down times
Phase-to-phase short
Motor overload
Loose connections
Problem with line power (See
Alarm 4 Mains phase loss
description)
Problem with the adjustable
frequency drive
Problem with motor or motor
wiring
Problem with the adjustable
frequency drives
Motor data are entered
incorrectly
Motor data are entered
incorrectly
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®
VLT HVAC Drive FC 102
Test
Check output limits in 4-13 Motor Speed
High Limit [RPM], 4-14 Motor Speed High
Limit [Hz] and 4-19 Max Output Frequency.
Check reference input signal scaling in 6-0*
Analog I/O Mode and parameter group 3-1*
References. Reference limits in parameter
group 3-0* Reference Limits.
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
adjustable frequency 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
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
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* Addl. 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 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 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 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.
MG11AK22