The frequency converter is an electrical device that converts 50HZ power into an AC power with adjustable frequency and voltage by using a variant circuit to drive a three-phase AC asynchronous motor. As a VFD composed of microelectronics technology and power electronic modules, it is greatly affected by ambient temperature, air humidity, mechanical vibration, dust and corrosive gases in actual applications, and its electrical performance will also change greatly.
Failure to maintain the frequency converter for a long time will lead to a decrease in operating efficiency and safety. In particular, dust and humid air, if not removed in time, will cause serious heating of the electronic components inside the equipment, causing equipment failure or shortening of service life. Therefore, it is necessary to perform regular maintenance on the equipment.
Daily inspection items:
(1) Whether there is any abnormal change in the sound during the operation of the motor, including whether there is any vibration during the operation of the motor.
(2) Whether the installation environment has changed. Regardless of whether the ambient temperature is normal, the operating temperature is generally in the range of -10℃~+40℃, preferably around 25℃.
(3) Whether the cooling fan is working normally, including whether the cooling channel is unobstructed. Whether the output data such as current, voltage, and frequency displayed on the display panel are normal. Check whether the characters on the display panel are clear and whether the strokes are missing.
(4) Whether it is overheated. Infrared thermometers can be used to detect whether the heat sink is overheated or has an odor. Check whether the equipment has a fault alarm display during operation.
(5) Clean the filter of the air inlet duct in the electric control cabinet regularly. Always keep the control cabinet and equipment in a good clean state. Effectively remove the surface dust on the equipment to prevent accumulated dust from entering the equipment. Especially metal dust. Effectively remove the oil stains on the equipment cooling fan.
(6) Use the annual maintenance time to open the equipment and focus the inspection on the internal cleaning that is not visible during normal daily operation. Clean the circuit board and its internal rectifier module, IGBT module, DC filter electrolytic capacitor, input/output inductor, etc. Use a brush or vacuum cleaner. Replace unqualified electronic components (Note: The internal filter capacitor of the inverter generally needs to be replaced every 4 to 5 years).
(7) Check the cooling fan: Since the cooling fan needs to run continuously for a long time, it is a component that is easily damaged. Its life is limited by the bearing (it is an axial flow fan). According to the service life of the fan or fan bearing, it is usually replaced every 2 to 3 years.