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DC motor starting method
- Nov 29, 2018 -

   Why can't the DC micro motor start directly? In the middle of the motor, a dangerous spark will be generated at the moment of starting, and the commutator will be burnt out, which will also cause damage to the winding, and will also cause large fluctuations in the grid voltage, causing an accident. The following Lihui motor share several DC micro motor starting methods for everyone.


1. Because the resistance and inductance of the armature circuit of the DC motor are small, and the rotating body has a certain mechanical inertia, when the DC motor is powered on, the armature speed and the corresponding back electromotive force at the beginning of the starting phase are small, and the starting current is very high. Big. Up to 15 to 20 times the rated current. This current can cause disturbances in the grid, mechanical shock to the unit, and sparks in the commutator. Therefore, the direct closing start is only applicable to motors with a power of no more than 4 kW.


2. DC motor starting methods include: direct closing start, series resistance starting and voltage reducing starting.


3. In order to limit the starting current, the starting control of the DC motor often adopts the method of step-down starting or armature circuit series starting resistor. For example, urban trams are often started. In order to simplify the equipment, reduce weight and facilitate operation and maintenance, a series resistance starting method is usually adopted.