Basic knowledge of motors (3)

Basic series technical parameters
1. Standard number JB/T9616-1996
2. Type of shell protection structure
The basic series of Y series small three-phase asynchronous motors has two levels of enclosure protection: IP23 and IP44. The meanings of IP23 and IP44 are: IP - - symbol indicating the protection level, and the requirements for the last two digits are shown in the following table:
The first digit of IP23 can prevent finger contact and live or rotating parts inside the casing, and can prevent small solid foreign objects with a diameter greater than 12MM from entering
The second digit should have no harmful effect on the motor when water is sprayed at an angle of 60 degrees or less along the vertical line
The first digit of IP44 can prevent tools, metal wires, or similar objects with a thickness greater than 1MM from touching live or rotating parts inside the casing, and can prevent small solid foreign objects with a diameter greater than 1MM from entering, but it does not include ventilation openings for external fans and drainage holes for enclosed motors. These parts should have Level 2 protection performance
The second digit should not have any harmful effects if water splashes into the motor in any direction.
3. Installation structure and type
The installation structure of Y series motors is divided into three types: foot installation, installation with foot and flange end cover, and installation with one flange end cover. According to the three basic installation structures, the installation types of electric motors are divided into horizontal installation, vertical installation, and shaft extension up or down, namely B3, B35, B5, V1, V3, B14, B34, etc. The specific models can be found in the standards.
4. Cooling method
The Y series motor is basically cooled by circulating the surrounding air.
The IP23 motor uses the fan blades on the rotor end ring as the driving element. The surrounding cold air enters from the end cover, is pressurized by the fan blades, carries some of the rotor heat, and then cools the stator winding ends and the back of the iron core. The heated air is discharged from the middle of the casing outside the machine.
The IP44 motor transfers all the heat generated by internal losses (iron loss, copper loss, mechanical loss) during operation to the surface of the motor. The fan installed at the non shaft extension end drives the surrounding air to continuously blow the surface of the motor, taking away the above heat and achieving the purpose of cooling the motor.
5. Power level and installation size
Check the table.
6. Main performance indicators
Some motors may have shorter iron cores and thinner enameled wires compared to other factories, but their power and other performance indicators meet the standard requirements.
7. Winding temperature rise
The Y series motor adopts B-level insulation, allowing a winding temperature rise of 80K. In addition, F-level insulation allows a winding temperature rise of 115K.
8. Operating conditions
(1) The altitude is not allowed to exceed 1000 meters, the maximum ambient temperature is not more than 40 ℃, and the minimum temperature is -15 ℃. The average highest humidity in the wettest month of the operating location is 90%, and the average lowest temperature in that month is not higher than 25 ℃.
(2) The power supply voltage is 380V ± 5%, the frequency does not vary by more than ± 1% at 50HZ, the imbalance of three-phase current under no-load does not exceed 10%, and under medium load does not exceed 5%. The no-load current is generally 30-55% of the load current.
Additional:
(1) The protection level of Y2 series motors and imported motors has reached IP54, IP55， In special circumstances, IP56 and IP65 can be achieved
(2) Imported motors (such as Siemens, ABB) use F-class insulation and B-class temperature rise insulation materials