In order to better grasp the knowledge of the motor, we must have a little understanding of the starting mode of the motor. There are several common starting mode of motor.
Reduced-voltage starting: This starting mode is the most common starting mode in the test motor of fundamental frequency power supply. Because the short-circuit test voltage is relatively low in motor test, such as the motor with 380v rated voltage, the voltage in short-circuit test is 100v, and each test unit has the condition of voltage adjustable.
Reduced-frequency starting: This is the most common way to start. In the test, it is specially equipped with frequency conversion power supply, the customer terminal uses frequency converter to start. Because of the energy saving demand, the frequency conversion motor has been applied well in the market, and the starting problem ofthe motor has also been solved. However, the frequency conversion can start the motor, not necessarily in the power frequency state of direct start, this kind of problems in the field of motor use has a specific case.
Series starting of winding rotor motor with frequency senstive resistance: This is the most common starting method of 3 phase asynchronous motor with collector ring structure. For test units with insufficient capacity of test equipment, this method will also be used to start.
Rotor soft starter starting: This is also a special starting mode of winding rotor motor. The structure uses a soft starter instead of a collector ring, which is commonly referred to as water resistance in the industry.