Single time constant(min)Short time constant (min)Long time constant (min)Weighting factor p25 2.6 41 0.430 3.1 49 0.435 3.6 58 0.440 4.1 60 0.445 4.8 75 0.450 5.1 82 0.455 5.6 90 0.460 6.1 98 0.465 6.7 107 0.470 7.2 115 0.475 7.8 124 0.4The default Max temperature setting is 105°C. This value is chosen since eventhough the IEC 60076-7 standard recommends 98°C as the maximum allowabletemperature in long-time loading, the standard also states that a transformer canwithstand the emergency loading for weeks or even months, which may producethe winding temperature of 140°C. Therefore, 105°C is a safe maximumtemperature value for a transformer if the Max temperature setting value is notgiven by the transformer manufacturer.4.1.6.6 SignalsTable 238:T2PTTR Input signalsName Type Default DescriptionI_A SIGNAL 0 Phase A currentI_B SIGNAL 0 Phase B currentI_C SIGNAL 0 Phase C currentBLOCK BOOLEAN 0=False Block signal for activating the blocking modeTEMP_AMB FLOAT32 0 The ambient temperature used in the calculationTable 239:T2PTTR Output signalsName Type DescriptionOPERATE BOOLEAN OperateSTART BOOLEAN StartALARM BOOLEAN Thermal AlarmBLK_CLOSE BOOLEAN Thermal overload indicator. To inhibite reclose.Section 4 1YHT530004D05 DProtection functions238 615 seriesTechnical Manual
