V
thresh
Threshold value (parameter Threshold)
k Curve constant k (parameter Charact. constant k)
α Curve constant α (parameter Charact. constant α)
c Curve constant c (parameter Charact. constant c)
Dropout
The greater dropout differential (= | pickup value – dropout value |) of the following 2 criteria
applies:
Dropout differential derived from the parameter Dropout ratio
If this parameter is not available, a dropout ratio of 95 % applies for the overvoltage and of 105 % for the
undervoltage functionality.
Minimum absolute dropout differential 150 mV sec.
Times
Operate time with time delay = 0 ms
Approx. 25 ms + OOT
28
at 50 Hz
Approx. 22 ms + OOT at 60 Hz
Dropout time Approx. 20 ms + OOT
Frequency Operating Range
0.9 ≤ f/f
rated
≤ 1.1 According to specified tolerances
10 Hz ≤ f < 0.9 f
rated
1.1 f
rated
< f ≤ 80 Hz
Slightly expanded tolerances
f < 10 Hz
f > 80 Hz
Active
Tolerances for Stage Type Definite Time-Overvoltage Protection
Voltages
0.5 % of the setting value or 0.05 V
Time delays 1 % of the setting value or 10 ms
Tolerances for Stage Type Inverse Time-Overvoltage Protection
Voltages
0.5 % of the setting value or 0.05 V
Operate time for
1.2 ≤ V/V threshold value ≤ 20
5 % of the setting value or 30 ms
Reset time delay 1 % of the setting value or 10 ms
28
OOT (Output Operating Time) additional delay of the output medium used, see chapter 11.1.4 Relay Outputs
Technical Data
11.19 Overvoltage Protection with 3-Phase Voltage
SIPROTEC 5, Low-Impedance Busbar Protection 7SS85, Manual 599
C53000-G5040-C019-6, Edition 06.2016