... the principle of relay protection.LONG TERM RECORD: 10 days CCS.SEAMLESS RECORDING: Withstands long periods of ... harmonic relayGenerator loss of field relayGenerator out of step relayGenerator over exciting relayGenerator frequency abnormal relayGenerator stator ... load relayTest: Generator open, short, synchronizing, destroy magnetic, 10% step;Accurate:Rated AC voltage, current @50Hz,25°C:0 ...