Equipment for protecting electrical systems including inverse-time-delay response

Claim 1

IN A RELAYING ASSEMBLY, A FIRST THREE-PHASE RELAY UNIT FOR PROTECTING A POLYPHASE ALTERNATING-CURRENT ELECTRICAL SYSTEM RESPONSIVE FOR OPERATION WHEN ENERGIZED BY ALTERNATING VOLTAGE AND CURRENT QUANTITIES OCCURRING DURING LINE-TO-LINE FAULT CONDITIONS OF A THREE-PHASE ALTERNATINGCURRENT ELECTRICAL SYSTEM ONLY TO A MAGNITUDE OF A FUNCTION OF IMPEDANCE HAVING A PREDETERMINED ANGLE WHICH FALLS IN A RANGE EXTENDING BETWEEN A FIRST MAGNITUDE AND A SECOND MAGNITUDE, A SECOND THREE-PHASE RELAY UNIT RESPONSIVE FOR OPERATION WHEN ENERGIZED BY ALTERNATING VOLTAGE AND CURRENT QUANTITIES OCCURRING DURING FAULTS INVOLVING THREE LINES OF THREE-PHASE ALTERNATING CURRENT ELECTRICAL SYSTEM TO A MAGNITUDE OF A FUNCTION OF IMPEDANCE, TIME-DELAY RELAY MEANS RESPONSIVE TO OPERATION OF ONE OF SAID RELAY UNITS FOR BEING TRANSFERRED FROM INEFFECTIVE TO EFFECTIVE CONDITION, SAID TIME-DELAY RELAY MEANS WHEN IN EFFECTIVE CONDITION HAVING A TIME-DELAY WHICH VARIES INVERSELY RELATIVE TO THE MAGNITUDE OF THE ENERGIZATION OF SUCH TIME-DELAY RELAY MEANS, AND TRANSLATING MEANS RESPONSIVE TO OPERATION OF THE TIME-DELAY RELAY MEANS.