Method and Device For Prevention and Protection of Electrical Transformer Against Explosion and Fire

A system for preventing, protecting and/or detecting explosion and/or resulting fire of electrical transformer (30) in advance before decomposition of combustible coolant fluid/dielectric oil, said system comprising:

• one or more differential current sensing electrical relay (26) for calculating the difference of input current and output current with the ceiling level and thereby providing first input to the control unit (1), if ratio of input current to output current exceeding more than the predetermined limit;
• wherein said input current and output current are the currents fi-om high voltage conductor (22) and low voltage conductor (23) of the electrical transformer (30) respectively;
• one or more buchholz relay (18) for sensing the excessive oil surge in the transformer and thereby providing second input to the control unit (1),
• one or more circuit breakers for obtaining input signals from current sensing electrical relay (26) aid buchholz relay (18) and thereby providing third input signal to control unit (1),
• one or more control unit (1) for receiving first, second and third input signals from the said differential current sensing electrical relay (26), buchholz relay (18) and circuit breakers (24, 28) respectively, and thereby generating control signal to energize lifting magnet (5) for draining of the combustible coolant fluid (11) through tile drain valve (4) and subsequently injecting inert gas from the bottom of the electrical transformer tank (14) through a nitrogen release valve (6) for stirring the combustible coolant fluid (11) and bringing down temperature and oxygen contents for preventative measures against the explosion and/or resulting fire in the electrical transformer (30).