Danfoss VLT FC 102 Instruction Manual page 47

Diagnostics and Troubleshoo...
WARNING 23, Internal 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).
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 adjustable frequency drive 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 adjustable frequency drive 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 adjustable frequency drive is still operational
but without the brake function. Remove power to the
adjustable frequency drive 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 energy is
higher than 90% of the brake resistance power. If [2] Trip is
selected in 2-13 Brake Power Monitoring, the adjustable
frequency drive trips when the dissipated braking energy
reaches 100%.
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VLT HVAC Drive Instruction Manual
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 adjustable frequency drive 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 adjustable frequency drive 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 adjustable
frequency drive power size.
Troubleshooting
Check for the following conditions.
ALARM 30, Motor phase U missing
Motor phase U between the adjustable frequency drive and
the motor is missing.
Remove power from the adjustable frequency drive and
check motor phase U.
ALARM 31, Motor phase V missing
Motor phase V between the adjustable frequency drive and
the motor is missing.
Remove power from the adjustable frequency drive and
check motor phase V.
ALARM 32, Motor phase W missing
Motor phase W between the adjustable frequency drive and
the motor is missing.
Remove power from the adjustable frequency drive and
check motor phase W.
MG11AJ22 - Rev. 2013-09-13
Ambient temperature too high.
Motor cable too long.
Incorrect airflow clearance above and below the
adjustable frequency drive.
Blocked airflow around the adjustable frequency
drive.
Damaged heatsink fan.
Dirty heatsink.
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