Service manual

Troubleshooting
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 fault in the motor.
WARNING 47, 24 V supply low
The 24 V DC is measured on the control card. The external
24 V DC backup power supply may be overloaded,
otherwise contact the Danfoss supplier.
WARNING 48, 1.8 V supply low
The 1.8 V DC supply used on the control card is outside of
allowable limits. The power supply is measured on the
control card. Check for a defective control card. If an
option card is present, check for an overvoltage condition.
ALARM 51, AMA check U
nom
and I
nom
The settings for motor voltage, motor current, and motor
power are wrong. Check the settings in parameters 1-20 to
1-25.
ALARM 52, AMA low I
nom
The motor current is too low. Check the setting in
4-18 Current Limit.
ALARM 53, AMA motor too big
The motor is too big for the AMA to operate.
ALARM 54, AMA motor too small
The motor is too small for the AMA to operate.
ALARM 55, AMA parameter out of range
The parameter values of the motor are outside of the
acceptable range. AMA does not run.
56 ALARM, AMA interrupted by user
The user has interrupted the AMA.
ALARM 57, AMA internal fault
Try to restart AMA again. Repeated restarts can over heat
the motor.
ALARM 58, Internal fault
Contact your Danfoss supplier.
WARNING 59, Current limit
The current is higher than the value in 4-18 Current Limit.
Ensure that Motor data in parameters 1-20 to 1-25 are set
correctly. Possibly increase the current limit. Be sure that
the system can operate safely at a higher limit.
WARNING 60, External interlock
A digital input signal is indicating a fault condition external
to the frequency converter. An external interlock has
commanded the frequency converter to trip. Clear the
external fault condition. To resume normal operation,
apply 24 V DC to the terminal programmed for external
interlock. Reset the frequency converter.
WARNING 66, Heatsink temperature low
This warning is based on the temperature sensor in the
IGBT module.
Troubleshooting:
The heatsink temperature measured as 0 °C could indicate
that the temperature sensor is defective, thus causing the
fan speed to increase to the maximum. If the sensor wire
between the IGBT and the gate drive card is disconnected,
this warning is produced. Also, check the IGBT thermal
sensor.
ALARM 79, Illegal power section configuration
The scaling card is the incorrect part number or not
installed. Also MK102 connector on the power card could
not be installed.
ALARM 80, Drive initialised to default value
Parameter settings are initialised to default settings after a
manual reset. Reset the unit to clear the alarm.
ALARM 95, Broken belt
Torque is below the torque level set for no load, indicating
a broken belt. 22-60 Broken Belt Function is set for alarm.
Troubleshoot the system and reset the frequency converter
after the fault has been cleared.
WARNING 200, Fire mode
This warning indicates the frequency converter is operating
in fire mode. The warning clears when fire mode is
removed. See the fire mode data in the alarm log.
WARNING 202, Fire mode limits exceeded
While operating in fire mode one or more alarm conditions
have been ignored which would normally trip the unit.
Operating in this condition voids unit warranty. Cycle
power to the unit to remove the warning. See the fire
mode data in the alarm log.
WARNING 250, New spare part
The power card or switch mode power supply has been
exchanged. The frequency converter type code must be
restored in the EEPROM. Select the correct type code in
14-23 Typecode Setting according to the label on the unit.
Remember to select ‘Save to EEPROM’ to complete.
WARNING 251, New typecode
The frequency converter has a new type code.
4.7
After Repair Tests
Following any repair to a frequency converter or testing of
a frequency converter suspected of being faulty, the
following procedure must be followed. Following the
procedure will ensure that all circuitry in the frequency
converter is functioning properly before putting the unit
into operation.
1. Perform visual inspection procedures as described
in Table 4.1.
2. Perform static test procedures to ensure that
frequency converter is safe to start.
3. Disconnect motor leads from output terminals (U,
V, W) of frequency converter.
Troubleshooting
VLT
®
HVAC Basic Drive Service Manual
MG90X202 - VLT
®
is a registered Danfoss trademark 39
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