Danfoss D9h Operating Manual page 143

VLT® AutomationDrive FC 302
Operating Guide
9.4.7 WARNING 6, DC Link Voltage Low
Cause
The DC-link voltage (DC) is lower than the low-voltage warning limit. The limit depends on the drive voltage rating. The unit is still
active.
9.4.8 WARNING/ALARM 7, DC Overvoltage
Cause
If the DC-link voltage exceeds the limit, the drive trips after a certain time.
Troubleshooting
• Extend the ramp time.
• Change the ramp type.
•
Activate the functions in parameter 2-10 Brake Function.
•
Increase parameter 14-26 Trip Delay at Inverter Fault.
•
If the alarm/warning occurs during a power sag, use kinetic back-up (parameter 14-10 Mains Failure).
• Connect a brake resistor.
9.4.9 WARNING/ALARM 8, DC Undervoltage
Cause
If the DC-link voltage drops below the undervoltage limit, the drive checks for 24 V DC back-up supply. If no 24 V DC back-up supply
is connected, the drive trips after a fixed time delay. The time delay varies with unit size.
Troubleshooting
• Check that the supply voltage matches the drive voltage.
• Perform an input voltage test.
• Perform a soft-charge circuit test.
9.4.10 WARNING/ALARM 9, Inverter Overload
Cause
The drive has run with more than 100% overload for too long and is about to cut out. The counter for electronic thermal inverter
protection issues a warning at 98% and trips at 100% with an alarm. The drive cannot be reset until the counter is below 90%.
Troubleshooting
• Compare the output current shown on the LCP with the drive rated current.
• Compare the output current shown on the LCP with the measured motor current.
• Show the thermal drive load on the LCP and monitor the value.
- When running above the drive continuous current rating, the counter increases.
- When running below the drive continuous current rating, the counter decreases.
9.4.11 WARNING/ALARM 10, Motor Overload Temperature
Cause
According to the electronic thermal protection (ETR), the motor is too hot.
This warning/alarm is controlled by parameter 1-90 Motor Thermal Protection:
• If the parameter is set to warning options, the drive issues a warning or an alarm when the counter is >90%.
• If the parameter is set to trip options, the drive trips when the counter reaches 100%.
The fault occurs when the motor runs with more than 100% overload for too long.
Troubleshooting
• Check for motor overheating.
• Check whether the motor is mechanically overloaded.
•
Check that the motor current set in parameter 1-24 Motor Current is correct.
•
Ensure that the motor data in parameters 1-20 to 1-25 is set correctly.
Danfoss A/S © 2021.10
Maintenance, Diagnostics, and
Troubleshooting
AQ262139143212en-000301 / 130R0879 | 143