Technical Data
4.3 Frequency Protection 81 O/U
SIPROTEC, 7RW80, Manual
C53000-G1140-C233-1, Release date 10.2010
187
4.3 Frequency Protection 81 O/U
Setting Ranges / Increments
Times
Dropout Difference
Dropout Ratio
Tolerances
Influencing Variables
Number of frequency elements 4; each can be set to f> or f<
Pickup values f> or f<
for f
Nom
= 50 Hz
40.00 Hz to 60.00 Hz Increments 0.01 Hz
Pickup values f> or f<
for f
Nom
= 60 Hz
50.00 Hz to 70.00 Hz Increments 0.01 Hz
Dropout threshold
= |pickup threshold - dropout threshold|
0.02 Hz to 1.00 Hz Increments 0.01 Hz
Time delays T 0.00 s to 100.00 s or ∞ (dis-
abled)
Increments 0.01 s
Undervoltage blocking
with three-phase connection: Positive sequence
component V
1
with single-phase connection (connection type "Vph-
n, Vsyn"): single-phase Phase-to-ground voltage
10 V to 150 V Increments 1 V
Pickup times f>, f< approx. 100 ms at f
Nom
= 50 Hz
approx. 80 ms at f
Nom
= 60 Hz
Dropout times f>, f< approx. 100 ms at f
Nom
= 50 Hz
approx. 80 ms at f
Nom
= 60 Hz
Δf = I pickup value - dropout value I 0.02 Hz to 1 Hz
Dropout Ratio for Undervoltage Blocking approx. 1.05
Pickup frequencies 81/O or 81U
Undervoltage blocking
Time delays 81/O or 81/U
15 mHz (with V = V
nom
, f = f
Nom
± 5 Hz)
3 % of setting value or 1 V
1 % of setting value or 10 ms
Power supply direct voltage in range 0.8 ≤ V
PS
/V
PSNom
≤ 1.15 1 %
Temperature in range 23.00 °F (-5 °C) ≤ Θ
amb
≤ 131.00 °F (55 °C) 0.5 %/10 K
Harmonics
- up to 10 % 3rd harmonic
- up to 10 % 5th harmonic
1%
1%