1. A PROTECTIVE RELAY FOR AN ELECTRICAL SYSTEM COMPRISING, A FIRST CIRCUIT DEVICE FOR DEVELOPING A FIRST SIGNAL DEPENDENT ON THE CURRENT IN SAID SYSTEM, A SECOND CIRCUIT DEVICE FOR DEVELOPING A SECOND SIGNAL DEPENDENT ON THE VOLTAGE OF SAID SYSTEM, A RELAY ELEMENT, FIRST CONTROL MEANS FOR APPLYING THE FIRST SIGNAL TO SAID ELEMENT IN A SENSE TENDING TO OPERATE THE ELEMENT WHEN ITS MAGNITUDE EXCEEDS A CERTAIN FINITE VALUE, SECOND CONTROL MEANS FOR APPLYING THE SECOND SIGNAL TO SAID ELEMENT IN A SENSE TENDING TO RESTRAIN ITS OPERATION, CIRCUIT MEANS FOR PROTECTING SAID SYSTEM IN RESPONSE TO THE OPERATION OF SAID ELEMENT IN DEPENDENCE ON THE RELATIONSHIP BETWEEN THE MAGNITUDES OF THE FIRST AND SECOND SIGNALS AND LIMITING MEANS FOR INHIBITING THE APPLICATION OF SAID SECOND SIGNAL TO SAID ELEMENT WHENEVER IT LIES BELOW A PREDETERMINED LOW VALUE AND RESTRICTING THE MAXIMUM MAGNITUDE OF THIS SIGNAL TO A PREDETERMINED HIGHER VALUE.