electric motor starter contactor

Starter
Control motor starting and stopping the use of electrical appliances. Motor starting, the starting current to exceed the motor rated current many times, starting current, the voltage of the line temporarily to be reduced. In case of large capacity, the voltage is lower, and it has little influence on the work of other electrical equipments on line. Therefore, the medium and small capacity AC motor can be used in direct starting mode. If the line voltage is reduced more, on the one hand, it will affect the operation of other equipments on the line. On the other hand, the starting torque of the motor will be reduced, the starting will be difficult, and even starting failure.
The starter is divided into two types, manual and automatic. The common use of a star delta starter in the manual starter of AC motor, which belongs to the starting mode of the buck. At the start, the winding is connected to the star, so that the applied voltage of each phase winding is reduced to the phase voltage to reduce the impact of the starting current. In the starting process, the three-phase winding is converted into a triangle by the method of triangle, and the starting of each phase voltage is raised to the line voltage. The manual starter of the DC motor is a series of current limiting resistance in the motor winding circuit to limit the starting current, and with the manual operation to cut series resistance, the speed of the DC motor is gradually increased, and the starting time of the whole series resistance is completed. The automatic operation of the starter is divided into two kinds of direct starting and decompression starting. The commonly used direct starter is electromagnetic starter, which has the function of loss of pressure and overload protection. Direct starters and two kinds of irreversible and reversible. The non reversible starter can only complete the starting and stopping of the motor; the reversible starter can accomplish the forward rotation starting, reverse rotation starting and stopping function. The automatic pressure relief starter has the self coupling decompression starter, the frequency sensitive starter and the integrated starter.