Suppression of the fires on objects of power represents quite difficult and labor-intensive process. It is connected with existence of a large amount of flammable substances and materials when which burning conditions, dangerous to the person, are created. The special danger is constituted by the fires on electric equipment where besides the main dangers there is also a defeat threat of electric current. For safety it is necessary to de-energize electric equipment before suppression that can take long time at which the fire will accept the considerable sizes. For implementation of actions for fire extinguishing on electric equipment without removal of tension from his current carrying parts, it is necessary to determine working parameters for fire extinguishing structures and means of their transportation and giving. The analysis of the carried-out works demonstrates that a large number of factors influences the safe conditions of application of fire extinguishing structures and means of their giving. One of types of fire extinguishing substance is sprayed water which is the main fire extinguishing component applied in installations of fire extinguishing with opportunities of hydroabrasive cutting. Feature of installations is the possibility of supply of fire extinguishing substances through protective designs directly to the seat of fire or a zone of burning. Respectively, when determining working parameters of installations of fire extinguishing with hydroabrasive cutting for their application at suppression of the fires of electric equipment pilot studies where the data array has been received have been energized conducted. Mathematical processing of the obtained experimental data by method of the regression analysis has been made for definition of the equations describing dependence of size of leak current on distance and tension. As a result of processing of experimental data dependences of size of leak current for water and mix of water and an abrasive have been received from distance and tension on subject to suppression. The received results are comparable to the results received earlier in works on determination of working parameters for manual fire trunks. It demonstrates to reliability of the received results and their correct processing. The received results allow to speak about a possibility of application of the considered installations of fire extinguishing for elimination of the fires which have arisen on electric equipment energized up to 30 kV from distance not less than 1 meter when using a dielectric set. Also received values need to be used at selection of knots and mechanisms to technical devices into which the fire extinguishing installation trunk, for their steady work and safety will be integrated.