FIELD: electrical engineering; low-voltage metal-clad switchgear. SUBSTANCE: magnetic starter designed for power distribution among ac motors of important drives running continuously has short-circuit protective gear of three fuses connected to terminals of first, second, and third phases, phase-failure protective gear incorporating three phase-failure relays with one contact at each relay, power contacts connected in series with fuses, overload protective gear, and control circuit; newly introduced in phase-failure protective gear are phase- shifting capacitors, each of them being connected between adjacent phases through respective contact of phase-failure relay; the latter has making contacts. EFFECT: enhanced effectiveness of starter phase-failure protection due to affording no-break operation of motor. 1 cl, 1 dwg
