Submersible pump control the type of what are

○ Three-phase AC induction motor starts running, the motor speed gradually rose from zero until the steady state of this process is called start. According to different start-up methods can be divided into:

Direct start

Step-down start

Frequency start

.1, start directly

○ switch (or contactor) directly connected to the motor power supply start-up called direct start;

○ Direct start of the start-up current, up to 7-15 times the rated current of the motor;

○ Advantages: large starting torque;

○ Disadvantages: As the starting current is large, will cause grid voltage fluctuations, and start the impact of large, easy to cause deep-well pump mechanical damage. Not suitable for more power (11KW above) the use of submersible pumps.

2, step-down start

○ Step-down start-up is the power supply voltage by a device appropriate step-down, and then applied to the motor, and gradually start the process of recovery to rated voltage during start-up.

○ buck start mode, due to the start of the lower start-up voltage, making the start-up current is reduced, usually, buck start-up impact current is 4-7 times the rated current of the motor.

○ Advantages: starting current is reduced, to complete the high-power motor start.

○ Disadvantages: low starting torque, large mechanical impact, demanding on the grid overload capacity.

3, frequency start

○ Frequency starting is the most advanced AC motor starting method, the principle is that the inverter will be continuously adjustable voltage and frequency applied to the motor to complete the smooth start of the motor.

○ Inverter start-up current can be controlled within the rated current of the motor.

○ Advantages: Start current is small, starting torque, no mechanical impact, will not cause impact on the power grid.

○ Disadvantages: easy to produce harmonics, thus undermining the motor insulation, damage to the motor bearings. By installing output reactor, the basic problem can be solved

Optical Regeneraltion & Anti-bacterial Filter

Optical Regeneraltion,Fiber Repeater ,Axon Foundation ,Diesel Regeneration

Reverse Osmosis System Co., Ltd. , http://www.nbfiltration.com