Underfrequency Protection - Siemens Siprotec 5 7SS85 Techical Data

11.28

Underfrequency Protection

Setting Values
Pickup values f<
Dropout differential
Time delay T
Minimum voltage
Times
Pickup times f<
Dropout times f<
Dropout
The larger dropout differential (= | pickup value – dropout threshold |) of the following two
criteria is used:
Dropout differential derived from the Dropout ratio parameter
If this parameter is not available, a dropout ratio of 95 % applies to the overvoltage protection and a dropout
ratio of 105 % applies to the undervoltage protection.
Minimum absolute dropout differential
Operating Ranges
Voltage range
Frequency range
Tolerances
Frequency f<
f - 0.20 Hz < f < f
rated
f - 3.0 Hz < f < f
rated
Time delay T(f<)
Minimum voltage
41 OOT (Output Operating Time) Additional delay of the output medium used, for example 5 ms with fast relay, see chapter
Outputs
SIPROTEC 5, Low-Impedance Busbar Protection 7SS85, Manual
C53000-G5040-C019-6, Edition 06.2016
+ 0.20 Hz
rated
+ 3.0 Hz
rated
11.28 Underfrequency Protection
40.00 Hz to 70.00 Hz
20 mHz to 2 000 mHz
0.00 s to 600.00 s
3.000 V to 175.000 V
Angle difference method
50 Hz
60 Hz
Filtering method
50 Hz
60 Hz
60 ms to 80 ms
150 mV sec.
5 V to 230 V (phase-phase)
Angle difference method
Filtering method
± 5 mHz at V = V
rated
± 10 mHz at V = V
rated
1 % of the setting value or 10 ms
1 % of the setting value or 0.5 V
Technical Data
Increments of 0.01 Hz
Increments of 10 mHz
Increments of 0.01 s
Increments of 0.001 V
Approx. 70 ms + OOT 41
Approx. 60 ms + OOT
Approx. 75 ms + OOT
Approx. 75 ms + OOT
10 Hz to 80 Hz
25 Hz to 80 Hz
11.1.4 Relay
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