Inverter Cooling Fan Maintenance Guide

The English abbreviation of the frequency converter is VFD or VVVF, which is an electrical device that drives a three-phase AC asynchronous motor by converting a 50HZ power supply into an AC power supply with adjustable frequency and voltage by using a variant circuit. As a frequency converter composed of microelectronics technology and power electronic modules, it is greatly affected by ambient temperature, air humidity, mechanical vibration, dust and corrosive gases in practical applications, and its electrical performance will also change greatly.

If the inverter is not maintained for a long time, the operation efficiency and safety will be reduced. In particular, dust and humid air, if not removed in time, will cause serious heating of the inverter and internal electronic components, causing the inverter to malfunction or shorten its service life. Therefore, it is necessary to carry out regular maintenance on the inverter.

Inverter daily inspection items:

(1) Whether the sound changes abnormally during the operation of the motor, including whether there is vibration during the operation of the motor.

(2) Whether the inverter installation environment has changed. Regardless of whether the ambient temperature is normal or not, the operating temperature of the inverter is generally within the range of -10°C to +40°C, preferably around 25°C.

(3) Whether the cooling fan of the inverter works normally, including whether the cooling channel of the inverter is unblocked. The inverter displays on the display panel whether the output data such as current, voltage and frequency are normal. Shows whether the characters on the panel are clear and whether the strokes are missing.

(4) Whether the inverter is overheated. Infrared thermometers can be used to detect if the heat sink of the inverter is overheated or smells bad. Check whether the inverter has a fault alarm display during operation.

(5) Regularly clean the filter screen of the air inlet pipe in the electric control cabinet. Always keep the control cabinet and frequency converter in good clean condition. Effectively remove surface dust on the inverter and prevent accumulated dust from entering the inverter. Especially metal dust. Effectively remove oil stains on the cooling fan of the inverter.

(6) Use the once-a-year maintenance time to turn on the inverter, and focus on cleaning the interior that cannot be seen during normal operation. Clean the circuit board of the inverter and its internal rectifier module, IGBT module, DC filter electrolytic capacitor, input/output reactor, etc. Use a brush or vacuum cleaner. Replace unqualified electronic components (note: the filter capacitor inside 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 an easily damaged part. Its life is limited by the bearings (it's an axial fan). Depending on the frequency converter, the fan or fan bearing is usually replaced every 2-3 years.