Zhuravel E. Development of methods of electric equipment safety rating for sites of collieries.

.The research object is a system of electrical supply and means of protection of colliery's site. The purpose of the work is the improvement of account and forecasting methods of equipment electrical safety. The development of reliability norms on protective switching - of and grounding at which a normalized level of electrical safety on collieries sites is provided. To reach the given objective analytical methods and methods based on experimental researches, theories, which are based on the main concepts of probability and reliability theories were used. The scientific importance of the work is developing of more perfect mathematical model (for electrical safety estimation), which allows to predict man's electrical shock probability from the various dangerous factors while exploiting coal - mining electrical equipment. The new block diagram of possible process of man's electrical shock formation was suggested and proved. The dependencies of frequency of a man's electrical shock from dangerous factor frequency and duration of their existence, switching - of reliability of both protective grounding and terms of their preventive maintenance are offered. The practical importance of the work is in improvement of an accounts technique allowing to estimate man's electric shock probability while exploiting electrical equipment and safety means and also in reliability basic norms on protective switching - of and protective grounding where normalized level of electrical safety is possible. Introduction area: suggested mathematical models and formulas are accepted by MakNII for further researches of the factors influencing electrical safety while operating with electrical equipment at collieries. The basic results of the work are in the basic of the document "The technique of a electrical safety rating for mining electrical equipment". The results of work are expedient for using by institutes MakNII, UkrNIIVE, when designing and determining reliability norms for protecting means and preventive maintenance terms, when estimating and forecasting electrical safety on objects which may cause man's electrical shock (the industrial enterprises, collieries etc.).