Abstract: This paper introduces the design principle, process, implementation and matters needing attention of the field control cabinet in petrochemical plant, which adopts positive pressure ventilation mode. For cabinets in hazardous areas, the explosion-proof requirements must be met. In order to achieve power supply before commissioning or startup, some practical suggestions are put forward, and the importance of the design of power supply system for cabinet is emphasized

Key words: petrochemical plant, positive pressure explosion, control cabinet