Danfoss VLT AQUA Drive FC 202 Operating Manual page 112

Operating Guide | VLT® AQUA Drive FC 202
Troubleshooting
• Check for proper fan operation.
• Cycle power to the drive and check that the fan operates briefly at start-up.
• Check the sensors on the control card.
8.4.21 WARNING 24, External Fan Fault
Cause
The fan warning function is a protective function that checks if the fan is running/mounted. The fan warning can be disabled in
parameter 14-53 Fan Monitor ([0] Disabled).
For drives with DC fans, a feedback sensor is mounted in the fan. If the fan is commanded to run and there is no feedback from the
sensor, this warning appears. For drives with AC fans, the voltage to the fan is monitored.
Troubleshooting
• Check for proper fan operation.
• Cycle power to the drive and check that the fan operates briefly at start-up.
• Check the sensors on the heat sink.
8.4.22 WARNING 25, Brake Resistor Short Circuit
Cause
The brake resistor is monitored during operation. If a short circuit occurs, the brake function is disabled and the warning appears. The
drive is still operational, but without the brake function.
Troubleshooting
• Remove the power to the drive and replace the brake resistor (refer to parameter 2-15 Brake Check).
8.4.23 WARNING/ALARM 26, Brake Resistor Power Limit
Cause
The power transmitted to the brake resistor is calculated as a mean value over the last 120 s of run time. The calculation is based on the
DC-link voltage and the brake resistor value set in parameter 2-16 AC Brake Max. Current. The warning is active when the dissipated
braking power is higher than 90% of the brake resistor power. If option [2] Trip is selected in parameter 2-13 Brake Power Monitoring, the
drive trips when the dissipated braking power reaches 100%.
8.4.24 WARNING/ALARM 27, Brake Chopper Fault
Cause
The brake transistor is monitored during operation, and if a short circuit occurs, the brake function is disabled, and a warning is issued.
The 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.
110 | Danfoss A/S © 2020.01
Maintenance, Diagnostics, and
Troubleshooting
AQ275652274277en-000101 / 130R0708