FIELD: digital short-circuit protective gear for traction lines of main railways, industrial enterprises, and subways. SUBSTANCE: method involves shaping values proportional to averaged value of current flowing in feeder under protection, to increment of current flowing in feeder, and to present value of increment setting. Two latter values are continuously compared and comparison results are used to shape OFF-signal for switch. EFFECT: improved selectivity and sensitivity of protective gear. 5 cl, 3 dwg, 1 tbl
