Interference with other electronic devices when the inverter is in use is a headache. If you are using it for the first time and do not know whether it is causing interference, you can explain the situation to the agent and ask it to be responsible for installing it. After everything is normal, then payment. After using a large number of frequency converters, we have found that a frequency converter with a relatively small interference has a common feature. For example, the inverter housing is an iron plate, a built-in reactor, a multi-layer circuit board, and the switching power supply of the switching power supply is an ordinary triode (non-field effect). Tube), the output module is the GTR module (now the new inverter has not been found). Anti-jamming is of course also related to the reasonable wiring of your power and control lines!
About the interference caused by the charging contactor to the inverter: After repairing the inverter with many communication faults, we found that the charging contactor inside the high-power inverter has a great relationship with this fault! When the inverter shows communication failure or frequent false alarm, the usual solution is to restore the parameters of the inverter to the factory default value, but this problem occurs again after the inverter runs for a while! Later, we charged the contactor coil (control terminal) and applied a filter, and received obvious results! By the same token, the contactor near the inverter will also interfere with the inverter. If the contactor is constantly moving, add a filter! Please do not use compressed air to blow the inverter: Today, a plastic factory in Dongguan sent a F540-110KW inverter for maintenance. The reason is that the electrician uses compressed air to blow the dust to the inverter. The compressed air generally contains water and gas, plus the inverter dust comparison. More, the inverter is not displayed after booting, and the power supply is damaged after checking the circuit board for short circuit! It is best to blow the dust to the inverter with a hair dryer! On the inverter interference problem: the inverter is like a powerful jammer when it is running. The source of the interference is on the 6 IGBT tubes of the output module. Some inverter switching power supplies will also cause certain interference. The line and the motor line are the antennas of the jammer. If the ground wire is poorly grounded, the interference signal can also be sent through the ground wire connected to the outer casing. The longer the line, the larger the interference range, not only disturbing the surrounding electronic equipment, but also disturbing the frequency conversion. The device itself! Some inverters have a certain amount of work in preventing interference signal radiation and input. The inverter will not malfunction frequently. Some inverters that cut corners sometimes cause headaches due to interference problems! If your control system is using the inverter and there are some electronic devices that communicate by analog signals and pulse signals, such as computers, man-machine interfaces, sensors, etc., you must be careful when purchasing inverters and wiring. There are many measures to prevent interference, such as adding reactors, filters, control lines and magnetic rings, using shielded wires (the control wires are not twisted together without shielded wires), and the inverter is placed in the iron cabinet (the inverter is an iron casing) Better), the power supply cable is placed in the iron pipe, the control wire should not be routed with the power cable, the wiring is arranged in an orderly manner, the carrier frequency is lowered, and the grounding is good. Many common terminals of the inverter control line cannot be grounded (many people connect ))! Checking how big the frequency converter is to the surrounding is also very simple, please bring a small radio! Preventing the interference of the inverter is sometimes a complicated problem. It is also necessary to combine the situation on the spot. Sometimes it has not been done for a few days! Sometimes it’s still unclear!
The factory ground wire is rarely broken, but after the break, it did not cause people to get an electric shock but burned the inverter! There is a brewery that damages more than a dozen Danfoss inverters at the same time. The phenomenon is that the motherboard terminals have a strong electric fire and burned the motherboard. According to the on-site investigation, there is a motor leakage, the ground wire of the factory is just rusted and broken, and the strong electric power is reversed into the inverter main board through the inverter ground wire! The ground wire is also very important for lightning protection. If the electrician is free, please ask him to check if the ground wire is broken quickly! If you have a lot of inverters in the same corner of your workshop; if you are a brewery, a beverage factory (wet environment); if you are a chemical plant, a ceramics factory (dusty); if you are a boiler plant (high temperature), you are the most It is good to install the inverter in an air-conditioned room, and you can receive unexpected results, which can greatly reduce the failure rate of the inverter! Greatly extend the life of the inverter.In order to improve the torque of the motor, some people often adjust the torque boost parameter (or the lowest output voltage) of the inverter to a high level! In this way, the starting current of the inverter will be very large, often jumping "overcurrent", and it is easy to damage the module! The torque boost should be appropriate. It can be adjusted slowly and observe the current. It is best to use “vector control†for large load. At this time, the inverter can automatically output the maximum torque, and the inverter should perform “tuning (self-learning)â€. But there are not many inverters that really have this function! It is impossible to reduce the basic frequency. The basic frequency of the domestic motor design is 50HZ. When the basic frequency of the inverter is reduced, although the torque can be increased, the current will rise sharply, causing damage to the inverter and the motor.
Some people do not take into account the "feel" of the inverter when debugging the inverter! Only adjust the acceleration/deceleration time to less than 1 second according to the production needs, the inverter is often bad. When the acceleration is too fast, the motor current is large, the inverter with good performance will automatically limit the output current, prolong the acceleration time, and the inverter with poor performance will Because the current is large, the life is reduced! The acceleration time is preferably no less than 2 seconds. When the deceleration is too fast, the inverter will be affected by the motor back electromotive force when the vehicle is stopped, and the module is also easily damaged! It is best to use the brake unit for the emergency stop of the motor. Otherwise, the deceleration time will be extended or the free parking mode will be adopted. Especially for large fans with very large inertia, the deceleration time is usually several minutes! Regarding the varistor problem, some inverters also have varistor at the input end, which should have a protective effect! However, according to the actual situation of the inverter we have repaired, the lightly injured only burns the copper wire of the circuit board. If the serious injury burns out the rectifier module, the switching power supply, the CPU board, and the capacitor, the cause of serious injury may be When the varistor is short-circuited, its metal fragments fly around; when it explodes, it emits strong static electricity and electromagnetic waves (much like lightning strikes); burning the copper wire of the circuit board makes the air switch not operate. Therefore, the pressure sensitive resistor on the outside of the inverter is much better! Many factories supply electricity to generators. When the generators are faulty, the output high-voltage power often burns the inverters and electronic instruments! This situation is what we have often seen. Last year, there was a wire drawing factory in Shenzhen that destroyed more than 20 sets of 30KW inverters at one time. It stopped production for ten days, causing heavy losses. The factory has a lot of protection methods in the generators. Too obvious! Later, we thought of a passive protection method, which is to add a varistor (380K for 380K, 220V471K) to the air switch at the input end of the inverter or instrument, so that when there is high voltage, the voltage sensitive will be short-circuited, the air switch Tripping, protection of the inverter, the inverter failure rate is greatly reduced, the varistor is very cheap, this method can be said to spend a small money to do big things! An electrician called and said that he found the inverter output voltage more than 1000 volts (input 380V) when testing the inverter. Is the inverter fault? Will it burn the motor? He still doesn't understand that the inverter will only step down and will not boost! ! It turns out that he is measuring with a digital multimeter. Since the output voltage of the inverter is a high-frequency carrier, the ordinary digital table without interference prevention is very inaccurate here!
KNM1 Series Moulded Case Circuit Breaker
KNM1 series Moulded Case Circuit Breaker is MCCB , How to select good Molded Case Circuit Breaker suppliers? Korlen electric is your first choice. All moulded Case Circuit Breakers pass the CE.CB.SEMKO.SIRIM etc. Certificates.
Moulded Case Circuit Breaker /MCCB can be used to distribute electric power and protect power equipment against overload and short-current, and can change the circuit and start motor infrequently. The application of Moulded Case Circuit Breaker /MCCB is industrial.
Korlen electric also provide Miniature Circuit Breaker /MCB. Residual Current Circuit Breaker /RCCB. RCBO. Led light and so on .
KNM1 series Molded Case Circuit Breaker,KNM1 series Small Size Molded Case Circuit Breaker,KNM1 series Electrical Molded Case Circuit Breaker,KNM1 series Automatic Molded Case Circuit Breaker
Wenzhou Korlen Electric Appliances Co., Ltd. , https://www.korlen-electric.com