Figure. 5.5.1. - 113. Combined operating time characteristics of voltage windows in function of voltage deviation to the set target
voltage.
From the operating characteristics it can be seen that the faster inverse operation until the U>>/<<
window threshold setting which after U>/< window threshold gives de nite operating time.
Settings for this example are:
U>/< pick-up = (1.2 * TAPEFF) / 2 = (1.2 * 1.67%) / 2 = 1%, Operating time 60 seconds.
U>>/<< pick-up = U>/< pick-up + TAPEFF = 1 % + 1.67% = 2.67%, Operating time 60 seconds.
For very high overvoltage AVR has an instant low function which lowers the voltage without any given
set time delay except the given minimum time between control pulses.
This function is used in the AVR until the measured voltage is below the set instant low threshold level.
After the set instant low threshold level is reached corresponding window time characteristics calculate
the consecutive time delays until the desired target window is reached.
AQ-T257
Instruction manual
Version: 2.00
219
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