Operation of asphalt mixing plant control system powered by three cabinets and a weak electricity control cabinet, power inside the electrical components adopt international famous brands, carefully made, safe and standard. Main power switch, circuit breaker, contactor, transformer, isolation transformers, power supply, inverter, switching power supplies. Cabinet layout as shown in Figure 4-23.

Circuit breaker, contactor constitutes the main circuit of motor control, also known as air circuit breaker switch, its main function is to protect the motor short circuit, overload, contactor used for remote access and off road and frequently starting control AC motors.

Powered cabinets 1 2000VA isolation transformer, used to provide isolated power supply control circuit, reduce the effects of power supply to the PLC.

Power supply used to power supply of the control circuit with a normal working voltage range, guarantee the normal operation of the device.

Frequency converter is used to complete the cooling aggregate gradation control, accurate measurement of mineral filler and asphalt. Working principle of frequency converter for: by adjusting the frequency of the motor to change the speed of the motor, in the case of motor with constant torque, adjust the operating voltage of the motor, so as to achieve the goal of energy saving.

24V DC power supply for all PLC driven by 24V digital inputs, analog inputs and provides drive power 24V relay output contact.