The dual power automatic transfer switch is a device capable of switching between two power sources. It is mainly used to detect power circuits and automatically switch the load circuit from one power source to the other. The following is the working principle of the dual power automatic transfer switch:

1. Real-time monitoring of power supply status
The dual power automatic transfer switch will conduct real-time detection of the effective value and phase of the three-phase voltage of the two power sources supplied by the three-phase four-wire grid. If overvoltage, undervoltage (including phase loss) or other situations occur in any phase, it can automatically switch from abnormal power supply to normal power supply to ensure the continuous and reliable operation of important loads.

2. Automatic switching function
When the common power supply malfunctions or there is a power outage, the dual power supply switching switch automatically switches to the backup power supply, ensuring that the equipment can still operate normally. This automatic switching function can automatically detect power fluctuations and quickly switch the power supply when necessary, avoiding equipment downtime caused by power issues.

3. Control logic and operation process
The controller of the dual power automatic transfer switch will simultaneously detect the voltage/current of both channels. The power supply voltage that is higher than the rated value (adjustable) will be judged as overvoltage, and the one that is lower than the rated value (adjustable) will be judged as undervoltage. The microcomputer control circuit makes logical judgments on the above detection results. The processing results are driven by a delay (adjustable) circuit to issue corresponding instructions to the electric operating mechanism for opening or closing.

4. Structural composition and safety performance
The dual power automatic transfer switch is usually composed of two three-pole or four-pole BM1 series molded case circuit breakers and accessories (auxiliary and alarm contacts), motor drive mechanism, mechanical interlock mechanism, intelligent controller, etc. These components work together to ensure the reliability and safety of the dual power automatic transfer switch during the switching process. For instance, there is a reliable mechanical interlock device and electrical interlock protection between the two actuating circuit breakers, completely eliminating the possibility of the two circuit breakers closing simultaneously.

In conclusion, the dual power automatic transfer switch ensures that it can quickly and reliably switch to the backup power supply when the main power supply fails through working principles such as real-time monitoring of power supply status, automatic switching function, control logic and operation process, structural composition and safety performance, as well as automation and remote control. This ensures the continuous power supply of the power system and the reliable operation of important loads.