Inverter routine maintenance and maintenance considerations - Solutions - Huaqiang Electronic Network

Photocoupler

The operator must be familiar with the basic working principle and function characteristics of the inverter maintenance and have basic knowledge of electrician operation. Before the inverter is inspected and maintained, it must be cut off when the total power supply of the equipment is completely turned off; and the inverter discharge indicator is completely extinguished.

Daily inspection matters

Before the inverter is powered on, the temperature and humidity of the surrounding environment should be detected. If the temperature is too high, the inverter will overheat alarm. In severe cases, the inverter power device will be damaged and the circuit will be short-circuited. If the air is too humid, the inverter will be directly short-circuited. When the inverter is running, pay attention to whether its cooling system is in normal production, such as whether the air duct is smooth or not, and whether the fan has abnormal sound. Generally, inverters with higher protection level, such as: IP20 and above, can be directly installed. The inverters below IP20 should be cabinet-mounted, so the heat dissipation effect of the inverter will directly affect the normal operation of the inverter. Exhaust system, such as whether the fan rotates smoothly, whether the air inlet has dust and obstructions are places that we can not ignore in daily inspection. Whether the motor reactor, transformer, etc. are overheated, have odor; whether the inverter and the motor have abnormal noise; whether the inverter panel current display is too large or the current change range is too large, and whether the output UVW three-phase voltage and current are balanced.

Regular maintenance

Clean the air filter to cool the air duct and internal dust. Check whether the screws, bolts, and plug-ins are loose. Whether the grounding and phase-to-phase resistance of the input/output reactor are short-circuited should be greater than tens of megaohms. Whether the conductor and the insulator are corroded, if necessary, wipe it with alcohol in time. When conditions permit, use an oscilloscope to measure the smoothness of the voltage output of each circuit of the switching power supply, such as: 5V, 12V, 15V, 24V and other voltages. The method of measuring the waveform of each circuit of the driver circuit is distorted. Whether the UVW phase waveform is a sine wave. Whether there is any ignition mark on the contact of the contactor, it is necessary to replace the new product of the same model or larger than the original capacity; confirm the correctness of the control voltage, perform the sequence protection action test; confirm that the protection display circuit is not abnormal; confirm that the inverter is running separately The balance of the output voltage.

Regular inspections are recommended and should be done once a year.

Replacement of spare parts

The frequency converter is composed of various components, some of which will gradually reduce and age after long-term work. This is also the main reason for the failure of the inverter. In order to ensure the long-term normal operation of the equipment, the following components should be replaced regularly:

(1) Cooling fan

The power module of the frequency converter is the most heat-generating device, and the heat generated by its continuous operation must be discharged in time. The life of the general fan is about 10kh~40kh. According to the continuous operation of the inverter, it is necessary to replace the fan for 2~3 years. The direct cooling fan has two lines and three lines. One of the two-line fans is positive and the other line is negative. Do not connect incorrectly when replacing. The three-wire fan is not only connected. There is also a detection line outside the negative pole. Please pay attention when replacing it, otherwise it will cause the inverter to overheat alarm. The AC fan is generally 220V, 380V, and the voltage level should not be mistaken when replacing.