Which parts of the VFD need to be replaced regularly

When we are using VFD, we must be familiar with the basic working principle and functional characteristics of VFD. Before the inspection and maintenance of the frequency inverter, the main power supply of the equipment must be cut off; and the Variable Frequency Drive indicator light must be completely extinguished.

Daily inspection items:

Before powering on the VFD, check the temperature and humidity of the surrounding environment. If the temperature is too high, it will cause the Variable Frequency Drive to overheat alarm. In severe cases, it will directly damage the VFD power components and cause a short circuit. If the air is too humid, it will cause a direct short circuit inside the frequency inverter. When the Variable Frequency Drive is running, pay attention to whether its cooling system is normal, such as: whether the air duct exhaust is smooth, and whether the fan has abnormal noise. Generally, VFDs with relatively high protection levels, such as: VFDs above ip20 can be installed directly open, and VFDs below ip20 should generally be installed in cabinets, so the heat dissipation effect of the inverter cabinet will directly affect the normal operation of the VFD, and the VFD's exhaust system such as a fan Whether the rotation is smooth, whether there is dust and blockages in the air inlet are the places that cannot be ignored in our daily inspection. Whether the motor reactor, transformer, etc. are overheated and have peculiar smell; whether the VFD and motor have abnormal noise; whether the VFD panel current display is too large or the current changes too much, and whether the output uvw three-phase voltage and current are balanced.

A VFD is composed of many electronic parts, and due to the composition or physical properties of the frequency inverter, deterioration occurs within a certain period of time, thereby reducing the characteristics of the frequency inverter and even causing failure. Therefore, for preventive maintenance, it is necessary to carry out regular replacement.

1. The rated current of the fuse is large and the load current is large. Under normal use conditions, the service life is about 10 years, and it needs to be maintained or even replaced during this time.

2. After the relay and contactor reach a certain cumulative number of switching times, poor contact occurs and needs to be checked and replaced.

3. Cooling fan
The Variable Frequency Drive main circuit semiconductor device cooling fan accelerates heat dissipation to ensure normal operation below the allowable Wendy. The life of the cooling fan is limited by the bearing, which is about 10000~35000h. When the VFD is running continuously, the fans or bearings need to be replaced after a few years

4. After using the timer for several years, the action time will change greatly, so replace it after checking the action time.

5. Capacitors
Large-capacity electrolytic capacitors are used in the intermediate DC circuit, and their performance will deteriorate due to the influence of pulse current and other factors. Deterioration is greatly affected by ambient temperature and use conditions. Generally, the service life is about 5 years. The deterioration of capacitors develops rapidly after a certain period of time. Therefore, the inspection period is a maximum of one year, and the end of life is within half a year.

For more details, please consult us, China VFD factory.