Toshiba GR-200-5 Instruction Manual page 142

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