Toshiba GR-200-5 Instruction Manual

Also see for GR 200 Series: Instruction manual Instruction manual Instruction manual Instruction manual Instruction manual

6F2T0207 (0.01)GRE200 (5,6)- 122 -Thermal overload function (THM)Apparatus such as cables, transformers, generators and others can become overheated whenoverloaded beyond their respective design limits due to excessive demands being placed on thesystem. The thermal overload function (THM) works by determining the temperature rise inan item of primary equipment by monitoring the current in order to detect the thermaloverload of the apparatus.THM has an exponential characteristics in accordance with the IEC 60255-149 standard.THM determines both theI2R loss and the cooling effect of the coolant simultaneously; THMalso determines the pre-load condition and signals a trip signal when an overload conditionarises.THM issues a trip signal in accordance with an alarm stage that reflects the temperatureof the thermal overload condition. The alarm stage is configured using a setting; hence, theuser should determine the appropriate setting so that a trip signal can be issued before theapparatus is overheated