Maintenance tips for frequency converter

In the work, because the inverter operators lack practical maintenance experience, they panic when encountering problems with the inverter. Here are six tips for maintaining the inverter to keep your inverter running smoothly:

1. When the inverter breaks down, it is best not to give it to someone who has no experience in inverter maintenance to repair it, otherwise it may get worse and worse. Sometimes the fuse blows, you must check whether there is a problem with the module. Some electricians have no experience and immediately install a good fuse (never replace it with copper wire), which results in the inverter burning out. According to our experience, if the fuse blows, the module is mostly problematic, but a module failure does not necessarily mean the fuse is broken. Many inverter power modules and rectifier modules are interchangeable. Try to buy the original model, but the price may be high.

2. Dust and moisture are the most deadly killers of the inverter. Especially after being shut down for a few days, the dust stuck on the circuit board will become damp. At this time, the inverter circuit board is most likely to spark and be damaged after power is supplied. It is best to install the inverter in an air-conditioned room or in an electric cabinet with a dust filter. Clean the dust on the circuit board and radiator regularly; it is best to blow the circuit board with a hair dryer before powering on the inverter that has been shut down for a period of time. It is best to add a brake resistor or use a mechanical brake for the inverter that often needs to be stopped urgently, otherwise the inverter will often be impacted by the motor's reverse electromotive force, and the failure rate will be greatly increased.

3. Some factories use generators for power supply, and the voltage is unstable, so the inverter is often damaged. The effect is better after the generator is equipped with voltage stabilization or overvoltage protection devices. In addition, the interference of the inverter is also a headache, which will prevent other electronic equipment from working properly. At this time, it is best to use shielded wires for the input, output, and control lines of the inverter, and the wiring method of the shielding layer cannot be wrong. Otherwise, the effect is the opposite. If possible, use an iron pipe to cover it, install a filter, and lower the carrier frequency. If the switching tube of the switching power supply of the inverter is a field effect tube (such as the K series), its interference will be greater. 11. In the process of repairing the inverter, we often encounter inverters that have been blown up after some factories have repaired them themselves, and the damage is more serious than before and more difficult to repair. Check the inverter, and it turns out that they used a repaired module. The repaired module is difficult to detect with an instrument, and all parameters are completely positive, but because of its rough internal wiring, the sealing silicone grease of the transistor cannot be sealed after opening. Some of these modules can be used for several months, and some will blow up as soon as they are turned on. Since the repaired module is opened and then reinstalled, it can be seen by careful identification that the copper sheet is glued with 502 glue, which feels hard. The glue of the original module is smoother and softer. Since the silicone grease inside the repaired module is cleaned out, the module becomes hollow, and the sound of knocking on its copper sheet is different. You can also disassemble the damaged module to see if the wiring is rough. Some fake modules are labeled separately, changing from one model to another, labeling low current as high current, and even labeling low voltage as high voltage. Now the label printing technology is becoming more and more simulated, but it can still be seen if it is carefully compared with the original module.

4. If the inverter is often running at low speed (less than 15HZ), the motor needs to be equipped with a cooling fan. When the cooling fan of some brands of inverters is broken, it will not issue overheat protection until the inverter is damaged, so when the fan makes a noise, it should be replaced. In addition, lightning protection is also very important. Although it rarely happens, when the inverter is struck by lightning, it will be severely damaged. The inverter with constant pressure water supply is most likely to be struck by lightning because it has a lightning-inducing water pipe extending to the sky.

5. Wiring problem: It is best to connect an air switch to the input end of the inverter. The protection current should not be too large to prevent the inverter from burning too seriously when a short circuit occurs. The "N" terminal must not be grounded, especially for experienced electricians. The control line should not be too long, because this will make the control board easily interfered by electromagnetic waves and cause malfunctions, which will also cause damage to the control board. It is best to use shielded wires for wires longer than 2 meters. Do not install a contactor with high current and frequent operation next to the inverter, because it will interfere with the inverter very much and often cause the inverter to malfunction (display various faults). Some people are greedy for convenience and always connect the starting control line. As soon as the inverter is powered on, the motor will start. In this way, the inverter is easy to burn out the charging resistor due to the large current flowing through the charging resistor. The ground wire should be well grounded, otherwise when the motor has serious leakage, the ground wire will be charged and the inverter will be damaged. The inverter should not be installed on equipment with vibration (such as injection molding machines, punching machines, washing machines). Because of this, the main circuit connecting screws inside the inverter are easy to loosen, and many inverters are damaged for this reason.

6. Selection of inverter brand: Don’t just look at the price. Some inverters are cheap, but the quality and performance are extremely poor. They cut corners, have a short lifespan, few accessories, and are difficult to repair. If you replace the entire circuit board, the repair fee will be sky-high. Some companies can promise warranty services, but your inverter may have to be shipped to a city thousands of miles away and take one or two months to repair. Although some inverters are famous brands, they are very delicate and require a good use environment to have good quality. Some inverters are equipped with "exclusive" components that are difficult to buy and expensive, so the maintenance fee is also high.

Another problem with inverters with poor performance is that once they burn out, it is quite serious and almost worthless to repair. The failure rate of inverters is relatively high, so when purchasing, you should understand whether it is easy to repair, such as whether there is a repair service center near you, whether the inverter module is universal, and whether it is easy to buy. If a certain inverter is used in large quantities, it is best to buy one or two more as backup. If your inverter is used for simple speed control, please choose a relatively cheap economical series. If the motor load is heavy and often stops suddenly, please choose an inverter with a larger capacity or better performance. More inverter selection knowledge and inverter purchase information can be found at Huanmao Ogilvy Inverter Sensor Home