Common Faults of Inverter-4
Overcurrent protection (OC):
1. When "FO OC" is displayed on the keyboard of the inverter, "OC" flashes. At this time, you can press the "∧" key to enter the fault query state, and you can find out the operating frequency, output current, and operating status at the time of the fault. And the size of the output current, determine whether its "OC" protection is overload protection or Vce protection (the output has short circuit phenomenon, drive circuit failure and interference, etc.).
2. If it is determined that the current is too large during acceleration due to the heavy load during the query, then properly adjust the acceleration time and the appropriate V/F characteristic curve.
3. If the motor is not connected, the dry-running inverter trips "OC" protection, and the power should be cut off to check whether the IGBT is damaged, and whether the junction capacitance between the freewheeling diode of the IGBT and GE is normal. If normal, you need to check the drive circuit: ① Check whether the plugging position of the drive line is correct, whether there is any offset, and whether it is falsely inserted. ② Check whether the "OC" is caused by defective HALL and wires. ③ Check whether there is a short circuit in the amplifier components of the drive circuit (such as IC33153, etc.) or the optocoupler. ④ Check the drive resistor for open circuit, short circuit and resistance change.
