The ZI * / * ET intrinsically safe power supply is intended for supplying intrinsically safe circuits with rated voltage Un = 5V, 12V, 15V and 24V DC. It is made in the form of a subassembly to be installed outside of a potentially explosive zone or in a flameproof enclosure ensuring IP54 protection. The PSU has been adapted to be supplied from AC mains with a nominal voltage of 24 – 42 – 133 – 231 (V AC / 50 Hz). The ZI * / * ET intrinsically safe power supply can be used in rooms with no risk of coal dust or methane explosion. In rooms at risk of explosion, the power supply is provided for installation in an explosion-proof housing with a flameproof enclosure. In rooms endangered only with coal dust explosion, the power supply can be built in a housing with at least IP54 protection degree.