Danfoss VLT HVAC Drive FC 102 Design Manual page 233

General Specifications and ...
Troubleshooting
Compare the output current on the LCP with the
adjustable frequency drive rated current.
Compare the output current on the LCP with
measured motor current.
Display the thermal drive load on the LCP and
monitor the value. When running above the
adjustable frequency drive continuous current
rating, the counter increases. When running
below the adjustable frequency drive continuous
current rating, the counter decreases.
See chapter 8.5 Special Conditions for more details if a high
switching frequency is required.
WARNING/ALARM 10, Motor overload temperature
According to the electronic thermal protection (ETR), the
motor is too hot. Select whether the adjustable frequency
drive gives a warning or an alarm when the counter
reaches 100% in 1-90 Motor Thermal Protection. The fault
occurs when the motor is overloaded by more than 100%
for too long.
Troubleshooting
Check for motor overheating.
Check if the motor is mechanically overloaded.
Check that the motor current set in 1-24 Motor
Current is correct.
Ensure that motor data in parameters 1-20
through 1-25 are set correctly.
If an external fan is in use, check in 1-91 Motor
External Fan that it is selected.
Run AMA in 1-29 Automatic Motor Adaptation
(AMA) to tune the adjustable frequency drive to
the motor more accurately and reduce thermal
loading.
WARNING/ALARM 11, Motor thermistor over temp
The thermistor may be disconnected. Select whether the
adjustable frequency drive gives a warning or an alarm in
1-90 Motor Thermal Protection.
Troubleshooting
Check for motor overheating.
Check if the motor is mechanically overloaded.
When using terminal 53 or 54, check that the
thermistor is connected correctly between either
terminal 53 or 54 (analogue voltage input) and
terminal 50 (+10 V supply) and that the terminal
switch for 53 or 54 is set for voltage. Check that
1-93 Thermistor Source selects terminal 53 or 54.
MG16C122
Design Guide
WARNING/ALARM 12, Torque limit
The torque has exceeded the value in 4-16 Torque Limit
Motor Mode or the value in 4-17 Torque Limit Generator
Mode. 14-25 Trip Delay at Torque Limit can change this from
a warning only condition to a warning followed by an
alarm.
Troubleshooting
WARNING/ALARM 13, Over current
The inverter peak current limit (approximately 200% of the
rated current) is exceeded. The warning lasts about 1.5 s,
then the adjustable frequency drive trips and issues an
alarm. This fault may be caused by shock loading or fast
acceleration with high inertia loads. If extended mechanical
brake control is selected, trip can be reset externally.
Troubleshooting
ALARM 14, Earth (ground) fault
There is current from the output phases to ground, either
in the cable between the adjustable frequency drive and
the motor or in the motor itself.
Troubleshooting:
Danfoss A/S © Rev. 2014-01-13 All rights reserved.
When using digital inputs 18 or 19, check that
the thermistor is connected correctly between
either terminal 18 or 19 (digital input PNP only)
and terminal 50. Check 1-93 Thermistor Source
selects terminal 18 or 19.
If the motor torque limit is exceeded during
ramp-up, extend the ramp-up time.
If the generator torque limit is exceeded during
ramp-down, extend the ramp-down time.
If torque limit occurs while running, possibly
increase the torque limit. Be sure the system can
operate safely at a higher torque.
Check the application for excessive current draw
on the motor.
Remove power and check if the motor shaft can
be turned.
Make sure that the motor size matches the
adjustable frequency drive.
Check parameters 1-20 through 1-25 for correct
motor data.
Remove power to the adjustable frequency drive
and repair the ground fault.
Check for ground faults in the motor by
measuring the resistance to ground of the motor
leads and the motor with a megohmmeter.
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