Abstract: As the electrical system of mine digging anchor machine always encounters maintaining difficulties and mechanical failure, the mainstream electrical design principles, cable introduction devices, and control methods of current anchor digging machine are studied. At the same time, programmable logic controller is selected as the main controller, and the explosionproof electric control box is optimized and redesigned. The optimized electrical control box for anchor digging machine is composed of external structure, distribution circuit, intrinsic safety electrical circuit, motor comprehensive protection circuit, and humanmachine interface. It also has the characteristics of rich interfaces, simple assembly, and convenient programming and debugging. Practical applications have shown that the use of this electric control box for the anchor digging machine is convenient for maintenance, low in failure rate, and high in excavation efficiency.

Key words: anchor digging machine, programmable logic controller, explosionproof, electrical control box, intrinsically safe circuit