Intrinsic Safety Design of Explosion-proof and Intrinsic Safety Type Electrical Control Box for Underground Mining Equipment

In order to solve problems that there are both intrinsic safety circuits and non-intrinsic safety circuits in explosion-proof and intrinsic safety type electrical control box for underground mining equipment and energy of the non-intrinsic safety circuits maybe transfer into the intrinsic safety circuits to damage explosion-proof and intrinsic safety performance, the paper introduced intrinsic safety design methods of explosion-proof and intrinsic safety type electrical control box for underground mining equipment in terms of structure design and electrical isolation, including structure arranging methods of electric interval, creepage distance, insulation, voltage resistance, terminal block, intrinsic safety wiring, transformer of power source and printed circuit board of intrinsic safety isolated barrier, and electrical isolation measures of isolation circuit for RS485 communication, isolation circuit for analog value, V/F converting circuit, isolation circuit for resistance signals, isolation circuit for switching value, isolation circuit for relay. The application showed that explosion-proof and intrinsic safety type electrical control box for mine-used control box by use of the methods is safe and reliable in performance and convenient in maintenance, which can meet explosion-proof requirement of coal mine underground.