Actuator is driven by high voltage circuit breaker drive mechanism for closing and opening mechanism. Actuator should meet the following basic requirements:

1. Should have sufficient operating power.

2. Rapid action is required.

3. An operating mechanism is reliable, simple structure, small size, light weight, easy to operate.

Correct and optimum selection of the circuit breaker operating mechanism is generally considered the following aspects:

a. The nature of the operation energy. The nature of the operation of the substation energy, the circuit breaker operating mechanism can choose one of the following forms: an electromagnetic actuating mechanism, a spring actuating mechanism, the hydraulic actuating means, pneumatic actuating mechanism. For new and expanded mining enterprises substation, should not then manually actuating mechanism.

b. Operating voltage. Actuator operation terminal voltage trip coil should be met: 25 to 30% lower than the rated voltage, shall not operate; 65% higher than the rated voltage of 25, should be reliable.

c. Working pressure. When using a hydraulic or pneumatic mechanism, when the working pressure is greater than 1MPa, there should be a pressure safety release.

d. Dust, moisture and ventilation. Shall actuating mechanism with dust, moisture, ventilation and small animals, hydraulic and pneumatic devices and the mechanism should be thermostatically controlled heating measures.