Siemens SIPROTEC 4 7SD80

Ground Fault Differential Protection in Resonant-grounded /
Isolated Systems
Pickup Values
Differential current;
87N L: IN(s)>
Ι
Nom
= 1 A
0.003 A to 1.000 A Increments 0.001 A
Operating Times
The operating times depend on the communication speed. The following data require a transmission rate of 512 kbit/s.
Pickup/trip times of the 87N L: IN(s)> element at
50 Hz or 60 Hz approx.
minimum 24 ms to 29 ms
Dropout times of the 87N L: I-DIFF> element
approx.
minimum 35 ms to 50 ms
Minimum current for direction determination
5% of setting value or 1 % Ι
Nom
Delay of the 87N L: I-DIFF> element approx. 1 % of setting value or 10 ms
Frequency range 45 Hz to 55 Hz at 50 Hz
55 Hz to 65 Hz at 60 Hz
25 Hz to 45 Hz at 50 Hz
30 Hz to 55 Hz at 60 Hz
Increased tolerances
Time Delays
Tripping delay
87N L:Trip-
Delay
0.00 s to 320 s Increments 0.01 s
Expiry tolerances 1 % of setting value or 10 ms
The set times are pure time delays.
Frequency Operating Range
Operating Range
0.8 ≤ f/f
Nom
≤ 1.2
stable at machine start-up (f = 0 to f
Nom
)
4.5
Technical Data
4.5 Ground Fault Differential Protection in Resonant-grounded / Isolated Systems
SIPROTEC 4, 7SD80, Manual 265
E50417-G1100-C474-A2, Edition 02.2018