February 5, 2025
The common faults of frequency inverters are overvoltage, overload, overcurrent and overheating. Generally, they are caused by high power supply voltage, high temperature, heavy load, dust and moisture, etc. A frequency inverter is an electronic product. Electronic products are composed of a large number of components. If any one component malfunctions, the frequency inverter will not work properly. Electronic products have a certain lifespan and will age after being used for a period of time, just like the birth, aging, illness and death of a person.
The service life and usage environment of frequency inverters
According to the tax calculation regulations for the depreciation of fixed assets, the minimum service life of electronic devices is only three years. Many people buy mobile phones and only use them for two to three years. Even if they don't break down, they often replace them with new ones. However, household appliances such as televisions, computers, refrigerators and air conditioners have a relatively lower obsolasing frequency. Their theoretical design lifespan can reach up to 15 years, but no one would use them for such a long time. Frequency inverters are industrial electronic devices and have a higher durability. It is not uncommon for some factories to have used frequency inverters for over 10 years. Some Japanese or German frequency inverters have even been in use for more than 20 years. Of course, during this period, the busbar capacitors are usually replaced. Domestic frequency inverters can generally be used for 5 to 8 years without any problem, as long as the workshop environment is good and maintenance is in place. The overall lifespan of frequency inverters is much longer than that of household appliances. Some chemical and plastic factories have corrosive gases, dust and static electricity. The frequency inverters are not protected in any way and professional frequency inverters are not purchased for use. The frequency inverters are directly installed in the workshop without separate compartments. As a result, they often break down within a year or two. Dust and corrosion can directly damage the circuit board and the soldering joints themselves. The static electricity or poor insulation they generate can directly cause electronic components to break down and get damaged. Some equipment vibrates very much, such as punch presses. In such situations, if frequency inverters are used and installed randomly with the equipment, they will also be jolted and vibrated together. Over time, the connection points of the frequency inverter lines will become loose, and the solder on the circuit board will also become loose due to prolonged vibration, causing problems like false soldering and resulting in damage. Some places are relatively humid, such as some water supply and drainage workshops, or some humidification areas, or in open-air usage environments. The humidity and high temperature may cause insulation breakdown and damage to the frequency inverters. To prevent the vfd inverter from being damaged and extend its service life, if conditions permit, the inverter should be installed in a separate electrical cabinet workshop and paired with air conditioners, exhaust fans and the like. This can reduce the probability of inverter damage.
Incorrect selection or improper use
A frequency inverter is used to drive a motor to work. It is a power source that changes frequency and voltage. The appropriate product needs to be selected based on the motor and load conditions. In the early days, in addition to general-purpose frequency inverters, there were also fan and pump types and vector types. Now, with the expansion of the application scope and the increase in the number of frequency inverters, many dedicated frequency inverters have been developed according to equipment, such as dedicated frequency inverters for elevators, dedicated frequency inverters for ball mills, and dedicated frequency inverters for spinning, etc. If a dedicated frequency inverter vfd is used, theoretically, it will be more capable of handling the corresponding load than a regular one, and can better cope with the current usage environment. Relatively speaking, it is less likely to break down. In some situations where frequent starts are required, the inverter needs to be used with an increased capacity to prevent damage caused by excessive temperature, or an external braking unit and braking resistor should be added to avoid the impact caused by long-term braking. In some situations, a short acceleration and deceleration time is not necessary. It should be appropriately extended. Some loads require low-speed operation. The frequency inverter vfd needs to avoid working in the low-frequency band. The actual operating frequency of the frequency inverter can be increased by raising the speed ratio, which can also extend the service life of the frequency inverter. In some areas with frequent lightning, when using frequency inverters, it is necessary to consider good grounding and add appropriate lightning protection devices. It is not uncommon for frequency invertersF to be damaged by lightning strikes. In some areas, due to significant fluctuations in grid voltage or relatively large load distances, it is also necessary to consider adding line reactors, busbar reactors, and output filters and other accessories.
Quality problems of frequency inverters
Imported brand frequency inverters, due to the accumulation of years of process data and the use of more reliable components, have a lower overall failure probability than domestic frequency inverters. Meanwhile, some big brand frequency inverters, because of their strict quality management systems, also have a longer service life than small brands. More expensive frequency inverters use modules with higher withstand voltage values and stronger current overload capacity. They also tend to choose better electrolytic capacitors and other components that are prone to aging. Overall, they are less likely to break down. There are relatively many harmonics in China's power grid. However, many small and medium-sized enterprise customers do not pay much attention to the usage environment of frequency inverters, which is rather harsh. When designing frequency inverters, these details often need to be taken into account. If manufacturers ignore these issues during the design process, problems are also likely to occur. The frequency inverter operates at high frequency, high voltage and large current for a long time. Although the possibility of being disturbed by other equipment is relatively low, it is not uncommon for it to affect itself. Appropriate PCB layout and reasonable software design are very important. Products from different manufacturers may vary.