Basic knowledge of the motor:
Small three-phase asynchronous motor, usually including H80-315MM motor, has a large output and wide application. In the total load of the power grid, its power consumption is about 40%. The JO2 series motors were popular in the early 1960s. The power ratings and installation dimensions of this series of motors are different from the common standards on the international market. In addition, the motor has low starting torque and lack of noise control indicators, so the motor currently used in China is now used. For the Y series motor. The motor is rugged, safe and reliable, so it is used in a wider range of applications. However, the annual damage rate of the motor used by some users is as high as 5%. The reason is mostly due to improper selection, improper use and poor protection. Therefore, the main purpose of this lecture is to find out the quality problems that occur in the use of the motor and properly solve it.
Small asynchronous motor system Small asynchronous motors can be divided into: basic series, derivative series and special series. The basic series is widely used and has a large production capacity. It is a general-purpose motor, such as the Y series (IP44) small three-phase asynchronous motor. The derivative series has been partially modified on the basis of different series of requirements according to different usage requirements. The other parts have a higher versatility and a certain degree of unity with the basic series. Derived series are electrically derived (such as high-efficiency motor, YX series), structural derivation (such as wound rotor motor YR series), special environment derivation (explosion-proof motor, YB series) and so on. The special series is different from general purpose and has special use requirements and special protection conditions series, such as YZ, YZR metallurgy and asynchronous motor for lifting.
Basic knowledge of the motor two:
Basic series technical parameters 1. Standard number JB/T9616-1996 2. Shell protection structure type Y series small three-phase asynchronous motor basic series There are two kinds of enclosure protection grades of IP23 and IP44. The meanings of IP23 and IP44 are: IP— indicates the sign of the protection level. The requirements of the following two digits are as follows: Level requirement IP23 The first digit can prevent finger contact and the charged or rotating part of the casing, which can prevent Small solid foreign objects with a diameter greater than 12 mm enter the second digit and the water spray at 60 degrees or less than the vertical line should have no harmful effect on the motor. IP44 The first digit can prevent tools, wires or similar with a thickness greater than 1MM. The object touches the charged or rotating part of the casing to prevent the entry of small solid foreign objects larger than 1MM in diameter, but does not include the vents that are sucked or supplied by the external fan and the drain holes of the enclosed motor. These parts should have level 2 The second digit of the protective performance is splashed on the motor in any direction and should have no harmful effects. 3. Installation structure and type The installation structure of Y series motor is divided into three types: the foot installation, the flange end cover with the ground foot and the flange end cover. According to the three basic installation structures, the installation type of the motor is divided into horizontal installation or vertical installation and shaft extension up or down, that is, B3, B35, B5, V1, V15 and other installation methods. 4, cooling method Y series motor is basically relying on the surrounding air to circulate cooling.
The IP23 motor uses the blades on the rotor end ring as the driving element. The surrounding cold air enters from the end cover, is pressurized by the blades, carries part of the rotor heat, and then cools the stator winding ends and the core back, and the heated air slave The middle of the shell is discharged outside the machine.
IP44 motor, the heat generated by the internal loss (iron loss, copper loss, mechanical loss) of the motor is transmitted to the surface of the motor. The fan is driven by the fan installed on the non-shaft end to continuously blow the surface of the motor and take away the heat. Achieve the purpose of cooling the motor. 5, power level and installation size look up the table. 6, the main performance indicators Some motors and other factories are likely to have a short core, enameled wire, but the performance of the motor and other performance indicators are in line with the standard requirements. 7. Winding temperature rise Y series motor adopts Class B insulation, which allows the winding temperature to rise to 80K. Another Class F insulation allows the winding temperature to rise to 115K. 8. Operating conditions (1) The altitude is not allowed to exceed 1000 meters, the ambient temperature is not more than 40 °C, and the lowest temperature is 15 °C. The wettest month and month average maximum humidity at the operating site is 90%, and the monthly average minimum temperature is not higher than 25 °C. (2) The power supply voltage is 380V±5%, the frequency is 50HZ and the variation is not more than ±1%. When the three-phase current is unloaded, the imbalance is not more than 10%, and the medium load is not more than 5%. The no-load current is typically 30-55% of the load current.
Basic knowledge of the motor three:
Nameplate data: General motor nameplate content model (TYPE): Voltage (VOLT): 380V Frequency (HZ): 50HZ Connection (CONN.) In general, 3KW and below motors are star-connected, and motors above 3KW are angled. . Power: No. (SER.NO.) Degree of protection (ENCL) Insulation class (INS.CLASS) Applicable standards: JB/T9616-1996 under normal conditions Noise [LW dB(A)] Number of revolutions (R/MIN) Rated current (AMP): Production date (DATE) Working system (DUTY) Weight (WGT) Special motor has the following identification three-phase asynchronous motor THREE PHASE INDUCTION MOTOR Service factor (S.F.) Current under service factor (S.F .A.) Efficiency EFF at 100% load. (100% FL) Efficiency EFF at 75% load. (75% FL) Ambient temperature limit MAX. AMB shaft end bearing type BRGS. P. E Non-shaft extension bearing type O. P. E. User’s other part number (PART.NO)
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