The correct way to buy a frequency converter - Database & Sql Blog Articles

Probe domestic high frequency needle JKT-50L high frequency needle with 3 probes

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First, understand the inverter model specifications and main parameters:
1. Rated power of the inverter: The maximum power of the inverter during operation. It is necessary to increase the capacity of the inverter according to the load and the environment.
2. Current of the limit: The running of the inverter is the maximum working current, and the current of the inverter must be greater than the rated current of the motor.
3. The rated voltage of the inverter: the working voltage of the inverter. 220v, 380v, 660v, 690v, 1140v and high voltage inverter
4, inverter overload capacity: fan pump inverter overload 120% versatile overload 150%
5, the parameters of the inverter can meet the requirements of use: usually the basic functions of the inverter can meet the requirements of conventional use, but some special industries need special functions, you need to choose the corresponding special inverter 2, according to load power, load The type is reasonably selected to have different loads, the load on the motor is different, and the requirements for the inverter are different.
1: Fan and water pump are the most common loads: the requirements for the inverter are the simplest, as long as the inverter capacity is equal to the motor capacity (air compressor, deep water pump, sediment pump, fast changing music fountain need to increase capacity) .
2: Crane type load: This type of load is characterized by a large impact at startup, so the inverter is required to have a certain margin and has a magnetic flux vector function. At the same time, if the elbow is placed under the weight, there will be energy feedback, so use the brake unit or use the common bus method.
3: Uneven load: Some loads are sometimes light and sometimes heavy. In this case, the inverter capacity should be selected according to the heavy load, such as rolling mill machinery, crushing machinery, mixer, etc. A frequency converter with a flux vector function can be selected.
4: Large inertia load: such as centrifuge, punching machine, rotary kiln of cement plant, such load has large inertia, so it may oscillate when starting, and energy feedback when the motor decelerates. A slightly larger frequency converter should be used to speed up the start-up and avoid oscillation. The brake unit is used to eliminate the feedback energy.
5: Long-term low-speed rotation, because the motor generates heat and the fan cooling capacity is reduced, it is necessary to adopt a method of increasing the reduction ratio or switching to a 6-stage motor to make the motor run near a higher frequency.
Third, according to the use of the environment (dust, temperature, humidity, altitude, corrosive gases) reasonable choice.
The frequency causes the inverter to be bad. It has a lot to do with the use environment. There are mainly the following:
1. Conductive dust and dust such as metal.
(1) Excessive conductive dust such as metal causes a short circuit in the main circuit.
(2) Dust is blocked and the temperature of the cooling fin is too high, causing tripping and burning.
2. Corrosive gas (1) The toggle switch is caused by corrosive gas, and the relay is in poor contact.
(2) Short circuit between crystals due to corrosive gases (3) Corrosion of terminals causes short circuit of main circuit.
(4) Circuit board corrosion causes short circuit between devices
3. Condensation, moisture, and dampness.
1) The door is discolored due to moisture, resulting in poor contact.
2) The phenomenon of ignition between the copper plates of the main circuit board due to moisture.
3) Inverting the internal resistance of the inverter to cause electrical corrosion and disconnection.
4) There is condensation in the insulating paper, causing discharge breakdown. If your environment has the above factors, the most effective measures are taken:
It is recommended to use Aosheng full-sealed frequency converter, which can be waterproof, dustproof and anti-corrosion. It can greatly reduce the failure rate and extend the service life of the inverter. Its international advanced vector control technology can automatically optimize the parameters and protect the inverter. Run in optimal use.
Fourth, other factors should not only look at the price, some inverters have low prices, but the quality and performance are extremely poor. It cuts corners, has a short life, fewer accessories, and is difficult to repair. If you change the entire circuit board, the maintenance cost will be sky-high. Some companies can promise warranty service, but your inverter may be shipped to a city thousands of miles away, and it takes a month or two to fix it. Some inverters are famous brands, but they are very delicate. They must have a good environment to have good quality. Some components assembled by the inverter are more "exclusively exclusive", difficult to buy and expensive, so the maintenance cost is also high. Another problem with poor performance of the inverter is that once it is burned, it is quite serious, and there is almost no maintenance value. The failure rate of the inverter is relatively high, so it is necessary to know whether it is convenient to repair when purchasing, such as whether there is a service center nearby. Whether the inverter module is universal or not, is it easy to buy. If a certain inverter is used in a large amount, it is best to buy one or two more for backup. If your frequency converter is used for simple speed control, please choose an economical series that is relatively cheap.
In summary:
Only when the inverter is properly purchased can the inverter you purchased be used normally, with low failure rate and long service life. Maximize your investment income.