In Order to Ensure the Safe and Stable Operation of the Frequency Converter, These Components Need t

1. Cooling fan

The power module of the frequency converter is a device with serious heating, and the heat generated by its continuous operation must be discharged in time. However, the service life of the cooling fan is limited by the bearing. After about 10000 35000 H (i.e. converted into 2 3 years according to the continuous operation of the frequency converter), the bearing, ball, motor, etc. of the fan are seriously worn, and the fan should be replaced once. It should be noted that the replacement period of the cooling fan is greatly affected by the ambient temperature. If abnormal sound and vibration are found during inspection, the cooling fan must be replaced.

2. Electrolytic capacitor

Large capacity electrolytic capacitors are used in the intermediate DC circuit. Due to the influence of pulse current and other factors, their performance will deteriorate, and the degree of deterioration is greatly affected by ambient temperature and service conditions. Generally, the service life is about 5 years. The deterioration of capacitors develops rapidly after a period of time, so the longest inspection cycle is one year, and it is better to be within half a year near the end of life.

3. Timer

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

4. Fuse

In the DC bus circuit of large brands of frequency converters, fuses are often used to play the role of short-circuit protection. With the extension of service time, under the influence of high current impact and temperature factors, the melt material performance will deteriorate, resulting in unnecessary faults of the frequency converter. For this reason, the fuse shall be replaced every 7 years.

5. Contactor / relay

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

6. PCB circuit board

In fact, the PCB circuit boards used inside the frequency converter, especially the switching power supply, voltage detection and other circuits, always need to bear high voltage, so the electrical insulation performance of this part of the circuit PCB board will be inversely proportional with the use time, which is very unfavorable for the use of multi-layer PCB circuit boards and some frequency converters with poor work quality. Therefore, for this part of the circuit, 7 years shall be taken as a replacement cycle.

After knowing 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. The 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 position and installation form, and then replace the required devices according to the same requirements.

2. All connectors shall be recorded or marked during disassembly to avoid dislocation during replacement or recovery.

3. The contact surface between the power device and the radiator shall be evenly coated with thermal conductive silicone grease and fastened with screws.

Affected by the external environment or its own structure, the frequency converter will deteriorate after being used for a period of time, which will reduce the characteristics of the equipment and even cause faults. Even if there are no obvious problems with the above six parts when they are used, it is still necessary to judge whether they can be replaced according to the service time after they are used for a long time, so as to prevent the use problems caused by the aging of their parts.

The source of the article: WeChat official account: frequency converter. Welcome to add attention! Please indicate the source of the article.