Abstract: The composition and level of Emergency Shutdown Device （ESD） systems on offshore oil platforms are discussed. The composition and functional realization process of ESD circuits of different electrical equipment in multiple projects in an oilfield are described,and their key role on offshore oil platforms is pointed out. The reliability of several ESD circuits is comprehensively analyzed and compared,and suggestions are put forward to improve the unreliable circuits. This study has guiding significance for the design and selection of ESD circuits in the secondary circuits of electrical equipment.

Key words: electrical equipment, ESD, reliability, comparison