Figure. 5.5.1. - 110. Setting recommendation. Set window is 20% bigger than tap step effect. This sensitivity is recommended for
stabile and calm operation. This ensures that after tap changing the voltage is not too near of the opposite voltage window
border. If more sensitivity is wanted, voltage window below 5% bigger than tap step effect is not recommended.
In the AVR applications rst window (U>/<
window
) is normally used for slower operation with de nite set
operating time on small deviations. Typically this operating time may be 30…120 seconds. Operating
time starts to count when the measured voltage exceeds either U> or U< setting limit. If this situation
continues until the set operating time tap change operation is applied. If measured voltage returns to
target voltage window operating time counter is reset. In the target voltage window 3% hysteresis is
applied for the U> and U< pick-up reset.
To de ne the second voltage window and settings for fast operation the setting limit should be
considered so that it is not used before one tap change cannot bring the voltage inside the set rst
voltage window.
AQ-T257
Instruction manual
Version: 2.00
© Arcteq Relays Ltd
216
