1. Power problem: check the power supply of the inverter is working properly, to ensure that the power supply voltage is stable and meet the requirements of the inverter. If there is a problem with the power supply, you need to find an electrician to overhaul and deal with it.
2. Cooling Fan Problems: The inverter will generate heat during operation, and needs to be cooled by a fan to maintain a stable working temperature. If the fan is aging or malfunctioning, there will be a buzzing sound. Check whether the fan is running normally, if the fan speed is not normal or produce abnormal noise, you need to replace the fan.
3. Capacitor problem: Capacitors inside the inverter may be damaged or aged, causing buzzing. Check the status of the capacitors inside the inverter, if found broken, leaking or deformed, etc., need to be replaced in time.
4. Control circuit failure: The control circuit of the frequency converter may be faulty, resulting in humming. Check the connection and components of the control circuit, if abnormalities are found, you can try to reconnect or replace the relevant faulty components.
It should be noted that the buzzing sound may represent a problem with the equipment, if the above methods do not solve the problem, it is recommended to contact the manufacturer of the frequency converter or a professional electrician for more in-depth overhaul and repair.