The ac motor with more than one kilowatt will be activated by the launcher
1, when the following conditions are met, the motor shall be fully pressed: When the motor starts, the voltage of the distribution bus is in accordance with the provisions of article 2.3.2 of this standard: Mechanical energy can withstand the shock torque when the motor is fully pressed. There is no special provision for the starting mode of the motor. When it is not in accordance with the condition of full pressure starting, the electromotive force is suitable for the starting up, or the other suitable starting way. The starting mode of the motor should be coupled with the speed adjustment mode when the speed adjustment is required.
This there is no hard and fast rules, basically see your lines and transformers, as well as the requirement for the quality of power supply, and the line protection fixed value setting, general motor impact current when starting for the normal 8 and 13 times that of the large capacity motor can cause voltage fluctuations, for high precision processing equipment production can say deadly, so considering comprehensive factors above, a lot of places can choose soft start way start or frequency converter drive, I have seen more than 200 kw, 100 kw motor USES the soft start, specific also depends on the enterprise itself situation, generally more than eighty kw adopt soft start more.
The start of the third motor Article 2.3.1 motor starting, the terminal voltage should be able to guarantee the mechanical requirements of starting torque, and caused by voltage fluctuations in the power distribution system should not interfere with other electric equipment work. Article 2.3.2 when ac motor starts, the voltage on the distribution bus shall meet the following rules: In general, when the motor is starting frequently, it should not be less than 90% of the rated voltage. When the motor does not start frequently, it should not be less than 85% of the rated voltage. 2, the load that is not connected to the light or other on the distribution bus line, and the motor does not start frequently, should not be less than 80% of the rated voltage.
If just use ordinary motor (do not include the power plant, industrial production using motor), you can refer to: civil, public power grid points directly power supply transformer and village power supply two kinds, the former is 11 kw allows direct start the following, which is 15 kw In fact, there are four factors to consider: When the motor starts, the voltage on the distribution bus at various levels meets the normal requirements of other devices; Mechanical energy is able to withstand the shock torque when the motor is fully pressed. The motor itself can withstand the shock of full pressure starting. There is no special requirement for motor start.
