Danfoss VLT CDS302 Operating Instructions Manual page 149

Troubleshooting
For the D, E, and F Frame filters, the regulated voltage to
the fans is monitored.
Troubleshooting
Check for proper fan operation.
Cycle power to the frequency converter and
check that the fan operates briefly at start up.
Check the sensors on the heatsink and control
card.
WARNING 24, External fan fault
The fan warning function is an extra protective function
that checks if the fan is running/mounted. The fan warning
can be disabled in 14-53 Fan Monitor ([0] Disabled).
Troubleshooting
Check for proper fan operation.
Cycle power to the frequency converter and
check that the fan operates briefly at start-up.
Check the sensors on the heatsink and control
card.
WARNING 25, Brake resistor short circuit
The brake resistor is monitored during operation. If a short
circuit occurs, the brake function is disabled and the
warning appears. The frequency converter is still
operational but without the brake function. Remove power
to the frequency converter and replace the brake resistor
(see 2-15 Brake Check).
WARNING/ALARM 26, Brake resistor power limit
The power transmitted to the brake resistor is calculated as
a mean value over the last 120 seconds of run time. The
calculation is based on the intermediate circuit voltage and
the brake resistance value set in 2-16 AC brake Max.
Current. The warning is active when the dissipated braking
is higher than 90% of the brake resistance power. If [2] Trip
is selected in 2-13 Brake Power Monitoring, the frequency
converter will trip when the dissipated braking power
reaches 100%.
WARNING/ALARM 27, Brake chopper fault
The brake transistor is monitored during operation and if a
short circuit occurs, the brake function is disabled and a
warning is issued. The frequency converter is still
operational but, since the brake transistor has short-
circuited, substantial power is transmitted to the brake
resistor, even if it is inactive.
Remove power to the frequency converter and remove the
brake resistor.
WARNING/ALARM 28, Brake check failed
The brake resistor is not connected or not working.
Check 2-15 Brake Check.
ALARM 29, Heatsink temp
The maximum temperature of the heatsink has been
exceeded. The temperature fault will not reset until the
temperature falls below a defined heatsink temperature.
The trip and reset points are different based on the
frequency converter power size.
MG34M302 - VLT
®
Operating Instructions VLT
Troubleshooting
Check for the following conditions.
ALARM 30, Motor phase U missing
Motor phase U between the frequency converter and the
motor is missing.
Remove power from 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.
Remove power from the frequency converter and check
motor phase V.
ALARM 32, Motor phase W missing
Motor phase W between the frequency converter and the
motor is missing.
Remove power from the frequency converter and check
motor phase W.
ALARM 33, Inrush fault
Too many power-ups have occurred within a short time
period. Let the unit cool to operating temperature.
WARNING/ALARM 34, Fieldbus communication fault
The fieldbus on the communication option card is not
working.
WARNING/ALARM 35, Option fault
An option alarm is received. The alarm is option specific.
The most likely cause is a power-up or a communication
fault.
WARNING/ALARM 36, Mains failure
This warning/alarm is only active if the supply voltage to
the frequency converter is lost and 14-10 Mains Failure is
NOT set to [0] No Function. Check the fuses to the
frequency converter and mains power supply to the unit.
ALARM 37, Phase imbalance
There is a current imbalance between the power units
ALARM 38, Internal fault
When an internal fault occurs, a code number defined in
Table 7.4 is displayed.
Troubleshooting
®
is a registered Danfoss trademark/Commercial Compressor
CDS302 and CDS303
Ambient temperature too high.
Motor cable too long.
Incorrect airflow clearance above and below the
frequency converter.
Blocked airflow around the frequency converter.
Damaged heatsink fan.
Dirty heatsink.
Cycle power
Check that the option is properly installed
Check for loose or missing wiring
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