Siemens SIPROTEC 7UT613 series, Руководство пользователя

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4.3 Restricted earth fault protection
441
7UT613/63x Manual
C53000-G1176-C160-2
4.3 Restricted earth fault protection
Setting Ranges
Operating Time
Frequency Influence
Figure 4-6 Tripping characteristic of the restricted earth fault protection depending on the
earth current ratio 3
I
0
"/3
I
0
' (both currents in phase + or counter-phase —);
I
REF
> = setting;
I
Trip
= tripping current
Differential current
I
REF
>/
I
NObj
0.05 to 2.00 Steps 0.01
Limit angle
ϕ
REF
110
°
(fixed)
Trip characteristic see Figure 4-6
Pickup tolerance
(with preset characteristic parameters and one
3-phase measuring location) 5 % at
I
< 5 ·
I
N
Time delay T
REF
0.00 s to 60.00 s
or
∞
(no trip)
Steps 0.01 s
Time tolerance 1 % of set value or 10 ms
The set times are pure delay times
Pickup time at frequency 50 Hz 60 Hz 16.7 Hz
at 1.5 · set value
I
REF
> approx. high-speed relays
35 ms 30 ms 110 ms
high-speed relays 30 ms 25 ms 105 ms
at 2.5 · set value
I
REF
> approx. high-speed relays
33 ms 29 ms 87 ms
high-speed relays 28 ms 24 ms 82 ms
Dropout time, approx. 26 ms 23 ms 51 ms
Dropout ratio approx. 0.7
Frequency influence within the frequency tagging range