The variables the user can set are binary signals from the system. The blocking signal needs to reach
the device minimum of 5 ms before the set operating delay has passed in order for the blocking to
activate in time.
The following figures present some typical applications for this function.
Figure. 5.3.7 - 40. Cable end differential with natural unbalance in the phase current measurement.
When calculating residual current from the phase currents, the natural unbalance can be around 10 %
while the used CTs are still within the promised 5P class (which is probably the most common CT
accuracy class). When the current natural unbalance is compensated in this situation, the differential
settings may be set to be more sensitive and the natural unbalance does not, therefore, affect the
calculation.
A
AQ
Q-T256
-T256
Instruction manual
Version: 2.06
84
© Arcteq Relays Ltd
IM00028
Summary of Contents for AQ-T256
Page 1: ...AQ T256 Transformer protection IED Instruction manual...
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