Figure. 5.4.16. - 67. Simpli ed function block diagram of the TRF function.
The TRF function outputs are dependent of the set transformer data in that sense that per unitized
measured currents are related to transformer nominal values. Following diagram presents the TRF
function outputs in various situations.
Figure. 5.4.16. - 68. TRF function outputs activation.
“No load” signal is activated when the current is under “No load current” limit (0.2 xIn)” for more than
10 ms time. If the current increases from this situation to “Heavy overloading limit (> 1.3 x In) then
“HV/LV inrush detection” signals are activated. If measured current is in between of low detection and
nominal current the “Load normal” signal is activated. If measured current is in between of nominal and
heavy overloading current “Overloading” signal is activated.
AQ-T257
Instruction manual
Version: 2.00
131
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