Several explosions were occurring on offshore oil platforms in the late 1980s due to installed motors which forced manufacturers to make their products non-incendive. Many organizations in the world have been actively involved in supporting the research and investigative work into the cause or causes of the explosions from the certified installed motor for hazardous area. Thereafter an increased safety concept which was developed in Germany and spread throughout the world for adopting in electrical motor. Increased Safety (Ex e) motor has covered a long journey to establish as an economical cheap and safe motor for explosive atmospheres. Various standards have been formed, amended, modified, reaffirmed and established worldwide to minimize the ignition risk from high voltage (HV) Ex e motors for safe use in hazardous areas. It is focused on background of the partial discharge phenomenon and remedial measures to get rid of from discharge in the HV motor as studied by researchers, technologists and manufacturers in this paper. The paper reviews the history of standards, motor development, causes of incendive discharge, risk factors, ignition risk assessment, and some design aspects to avoid ignition source from these motors in explosive atmospheres.
Bhagirath Ahirwal (Thu,) studied this question.