FIELD: welding technique, namely plasma processes in different industry branches. SUBSTANCE: plasma system includes burner having electrode and nozzle with plasma arc opening for extending electrode towards welded products and input transformer with primary winding circuit and secondary winding circuit. Secondary winding circuit is excited by means of primary winding circuit. First circuit is joined with secondary winding circuit for creating starting arc through electrode and nozzle. Second circuit is joined with secondary winding circuit for creating plasma arc through electrode and welded product. Switch is provided for selectively switching between first and second circuits. Secondary winding circuit includes first winding with first effective turn number for exciting first circuit and second winding with second effective turn number for exciting second circuit. First and second effective numbers of turns may be different in order to provide operation of burner with different windings at starting arc mode and cutting mode. EFFECT: quick switching of arc from starting mode to cutting mode, smaller primary electric current values, enhanced effectiveness of system. 26 cl, 12 dwg
