Frequency converter internal needs regular replacement of six parts

Frequency converter internal needs regular replacement of six parts

Six parts of the inverter that need to be replaced regularly

In the field of electrical control nowadays, the inverter is definitely the leading star. Helpless as a frequency converter that integrates electrical and electronic technologies, it is by no means an invincible body! In order to ensure the safe and stable operation of the inverter, in addition to regular inspection and cleaning, various internal components must be replaced regularly. Which parts need to be replaced regularly?

01Cooling fan

The power module of the inverter is a device with serious heat, and the heat generated by its continuous operation must be discharged in time. However, the life of the cooling fan is limited by the bearing. After about 10,000 to 35,000 hours (that is, 2 to 3 years according to the continuous operation of the inverter), the bearings, balls, and motors of the fan are seriously worn out, and the fan needs to be replaced once. It should be noted that the replacement period of the cooling fan is greatly affected by the surrounding temperature. If abnormal sound or vibration is found during the inspection, the cooling fan must be replaced.

02 electrolytic capacitor

High-capacity electrolytic capacitors are used in the intermediate DC circuit. Due to the influence of pulse current and other factors, their performance will be deteriorated, and the degree of deterioration is greatly affected by the surrounding temperature and use conditions. Under normal circumstances, the service life is about 5 years. The deterioration of the capacitor develops rapidly after a period of time, so the longest inspection period is one year, and it is best to be within half a year when the end of life is approaching.

03 timer

After the timer has been used for several years, the operating time will change greatly, so it is best to replace it after checking the operating time.

04 Fuse

In the DC bus circuit of major brands of inverters, fuses are often used for short-circuit protection. As the use time is prolonged, under the impact of large current and temperature factors, the performance of the melt material will often be degraded, causing the inverter to malfunction. For this reason, the fuse needs to be replaced every 7 years.

05 Contactor\Relay

After the relay and contactor reach a certain cumulative switching times, poor contact occurs later, which requires inspection and replacement.

06PCB circuit board

In fact, the PCB circuit boards used in the inverter, especially the switching power supply, voltage detection and other circuit parts, always need to withstand high voltage, so the electrical insulation performance of this part of the circuit PCB board will be inversely proportional to the use of time. This is for the use of multilayer PCB circuit boards. Compared with some inverters with poor workmanship, it is very disadvantageous. For this part of the circuit, 7 years should be used as a replacement cycle.

After understanding the components that may need to be replaced, we also need to pay attention to the basic requirements for replacing components:

1. Determine the basic parameters and appearance of the device to be replaced. Basic parameters include external size, capacitance of capacitor, resistance value of resistor, value of GTR Darlington (current amplification factor), switching characteristics and saturation voltage of IGBT (including IPM) devices, etc. The appearance requirements include external dimensions, terminal location and installation form, etc., and then replace the required components according to the same requirements.

2. Records or marks should be made when disassembling all connectors to avoid dislocation during replacement or restoration.

3. The contact surface of the power device and the radiator should be evenly coated with thermal grease and fastened with screws. The inverter is affected by the external environment or its own structure, and it will deteriorate after a period of use, thereby reducing the characteristics of the equipment and even causing malfunctions. Even if the above six components have no obvious problems when they are used, after a long time of use, it is necessary to judge whether they can be replaced according to the time of use to prevent the aging of their parts and cause use problems.