FIELD: electric safety engineering; relay protection of electrical equipment.
SUBSTANCE: proposed method designed for use in low-voltage switchgear and control gear of quarry excavators involves measurement of insulation resistance in ac voltage circuits of all power supplies and in dc voltage circuits of lifting, head, and turn generators, determination of RUNNING or ADJUSTMENT mode of excavator operation, and disconnection of electrical equipment on occurrence of insulation resistance drop in one of mentioned circuits below permissible level: in ADJUSTMENT mode it is made instantly and in RUNNING mode, with time delay sufficient for emergency termination of executed operation within which sound alarms and light signals are generated indicating point of ground fault for driver.
EFFECT: enhanced efficiency of controlling emergency disconnection of electrical equipment in response to ground fault.
1 cl, 1 dwg
