Danfoss VLT HVAC Basic Drive Programming Manual page 79

Troubleshooting
Display the Thermal Drive Load on the LCP and
monitor the value. When running above the drive
continuous current rating, the counter should
increase. When running below the drive
continuous current rating, the counter should
decrease.
NOTE
See the derating section in the Design Guide for more details
4 4
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 frequency converter
gives a warning or an alarm when the counter reaches 100%
in 1-90 Motor Thermal Protection. The fault is that the motor is
overloaded by more than 100% for too long.
Troubleshooting:
Check if motor is over heating.
If the motor is mechanically overloaded
That the motor 1-24 Motor Current is set correctly.
Motor data in parameters 1-20 through 1-25 are set
correctly.
Run AMA in 1-29 Automatic Motor Adaption (AMA).
WARNING/ALARM 11, Motor thermistor over temp
The thermistor or the thermistor connection is disconnected.
Select whether the frequency converter gives a warning or
an alarm in 1-90 Motor Thermal Protection.
Troubleshooting:
Check if motor is over heating.
Check if the motor is mechanically overloaded.
Check that the thermistor is connected correctly.
If using a thermal switch or thermistor, check the
programming of 1-93 Thermistor Source matches
sensor wiring.
WARNING/ALARM 13, Over current
The inverter peak current limit is exceeded. The warning lasts
about 1.5 sec., then the frequency converter trips and issues
an alarm.
Troubleshooting:
This fault may be caused by shock loading or fast
acceleration with high inertia loads.
Turn off the frequency converter. Check if the
motor shaft can be turned.
Check that the motor size matches the frequency
converter.
Incorrect motor data in parameters 1-20 through
1-25.
78
VLT HVAC Basic Drive Programming Guide
ALARM 14, Earth (ground) fault
There is a discharge from the output phases to earth, either
in the cable between the frequency converter and the motor
or in the motor itself.
Troubleshooting:
ALARM 16, Short circuit
There is short-circuiting in the motor or on the motor
terminals.
Turn off the frequency converter and remove the short-
circuit.
WARNING/ALARM 17, Control word timeout
There is no communication to the frequency converter.
The warning will only be active when 8-04 Control Timeout
Function is NOT set to OFF.
If 8-04 Control Timeout Function is set to Stop and Trip, a
warning appears and the frequency converter ramps down
until it trips, while giving an alarm.
Troubleshooting:
WARNING 24, Fan fault
The fan warning function is an extra protection function that
checks if the fan is running / mounted. The fan warning can
be disabled in 14-53 Fan Monitor ([0] Disabled).
Troubleshooting:
ALARM 30, Motor phase U missing
Motor phase U between the frequency converter and the
motor is missing.
Turn off the frequency converter and check motor phase U.
ALARM 31, Motor phase V missing
Motor phase V between the frequency converter and the
motor is missing.
Turn off the frequency converter and check motor phase V.
®
MG.18.B1.02 - VLT is a registered Danfoss trademark
Turn off the frequency converter and remove the
earth fault.
Measure the resistance to ground of the motor
leads and the motor with a megohmmeter to check
for earth faults in the motor.
Check connections on the serial communication
cable.
Increase 8-03 Control Timeout Time
Check operation of the communication equipment.
Verify proper installation based on EMC
requirements.
Check fan resistance.