FIELD: electrical engineering. SUBSTANCE: interrupter has electromagnetic operating mechanism incorporating H-shaped magnetic circuit 7 with first air gap accommodating movable contact arm 5 and second air gap formed between moving element 8 turning about axis and pole shoe of magnetic circuit 7. Change-over mechanism 9 is connected to moving element 8 to ensure displacement of contact arm 6 towards open position. Change-over mechanism 9 is formed by elongated part located between magnetic circuit 7 and first chamber 30; this part is engageable with fastening member of contact arm 5 so as to block passage between first and second chambers 30, 32 upon attraction of moving element and to open mentioned passage upon reset of moving element 8 to open position. EFFECT: improved reliability under all environmental conditions. 4 cl, 6 dwg
