Maintenance and overhaul of inverter

Inverter is a kind of variable speed drive system software. It uses DC variable frequency drive technology to change the frequency and strength of Brake AC Gear Motors Company working standard voltage to smoothly control the speed and torque of AC motor. The most common one is that the input and output are all AC current. Communication/communication converter. The frequency converter has a wide range of applications, from small and medium-sized household appliances to large and medium-sized mine grinding equipment and refrigeration compressors. About 1/3 of the world's kinetic energy is consumed on motors that drive fixed-speed centrifugal water pumps, cooling fans and refrigeration compressors, and the market penetration rate of frequency converters is still not high. The obvious improvement of the high efficiency of electric energy is one of the key reasons for the application of frequency converters. With the continuous promotion of industrial automation, the application of frequency converters in the industrial production industry has become more and more common, and the maintenance and repair problems also seem to be increasingly critical.

Three elements for high-efficiency operation of frequency converters:
1. Common problems during normal operation
1. Is there any abnormal noise and vibration in the motor?
2. Whether the inverter and motor are hot and abnormal.
3. Is the working temperature too high?
4. Is the load current meter the same as the previous value?
5. Is the cooling fan of the inverter operating normally?
Note: The daily maintenance and repair of the inverter must be carried out in accordance with the product manual.

 2. Usual inspection matters
1. Check the refrigeration system and eliminate the dust in the air filter.
2. Check whether the standard parts on the inverter such as screws and anchor bolts are loose, and carry out the necessary tightening; check whether there are erosion, discoloration, cracks, damage, etc. Welding parts and riveting terminals, and check whether the frame shear wall is loose, whether the transmission lines and cables are damaged, etc.
3. Check whether the connection of the control circuit board is loose, whether the power capacitor is leaking, whether the line on the board is rusted or cracked, etc.
4. Check whether the coupling capacitor is leaking and whether the capacitor is reduced.
5. Check whether the grounding resistance is within the standard value range.
Note: It is suggested that regular maintenance should be carried out once a year.

3. Replacement of accessories
To make the frequency converter operate reliably for a long time, it is necessary to carry out maintenance on time for the service life of the electronic components in the frequency converter, and to dismantle and replace the key components of the frequency converter according to the service life.
1. The switching power supply of the cooling and cooling fan inverter is the most serious heating device. The heat generated during continuous operation must be discharged immediately. The damage of the centrifugal fan is not easy to warn and cannot be estimated. Therefore, the time must be removed and replaced. Because it's small and big. The service life of the general cooling fan is 10kh-40kh. According to the continuous operation of the inverter, the cooling fan should be removed and replaced once every 2 to 3 years, and the cooling fan for immediate cooling has the difference between the second and the third line. The first line of the second line cooling fan is the positive stage and the other line is the negative stage. In addition to the positive and negative stages of the three-wire cooling fan, there are also inspection stations. When disassembling and replacing, always pay attention to communication. The AC centrifugal fan is generally 220v, 380v point is 220v, and 380v point. The working voltage level of disassembly and replacement should not often fail. Reliable universality The well-known brand inverter power supply will have a professional maintenance chapter catalog in the hardware configuration guide, and the key initial use period, replacement cycle time, etc. will be marked internally. If there is no such content, it means that the inverter you purchased is not a well-known brand, and it is suggested to replace it.
2. Electrolytic capacitor The key passive components in the inverter, which are composed of inductors, capacitors, resistors, etc., are called filters. Its function is to get a special frequency or clear a special frequency. The volume size of the coupling capacitor is positively related to the amount of current in operation. In other words, the larger the amount of current in operation, the larger the volume of the necessary capacitor. The service life of power capacitors is generally 5 years. The volume of the capacitor should be regularly maintained once a year. Generally, it should be replaced when the volume is reduced by more than 20%.