Undervoltage Protection
Setting Ranges / Increments
Measured quantity Positive Sequence phase-to-earth voltages as
phase-tophase values
Pickup Thresholds U<, U<< 10.0 V to 125.0 V Increments 0.1 V
Dropout Ratios DR
(only stages U<, U<<)
1.01 to 1.20 Increments 0.01
Time Delays T U<, T U<< 0.00 s to 60.0 s
or ∞ (unwirksam)
Increments 0.01 s
The set times are pure delay times with definite time protection.
Times
Pickup times
50/60 Hz approx. 30 ms
16.7 Hz approx. 70 ms
Dropout times
50/60 Hz approx. 30 ms
16.7 Hz approx. 70 ms
Tolerances
Pickup voltages U<, U<< 1 % of setting value or 0.5 V
Delay times T 1 % of setting value or 10 ms
Influencing Variables for Pickup Values
Power supply direct voltage in range
0.8 ≤ U
H
/U
HN
≤ 1.15
≤ 1 %
Temperature in range
–5 °C ≤ Θ
amb
≤ 55 °C
≤ 0.5 %/10 K
Frequency in range 0.95 ≤ f/f
N
≤ 1.05 ≤ 1 %
Harmonics
- up to 10 % 3rd harmonic
- up to 10 % 5th harmonic
≤ 1 %
≤ 1 %
4.14
Technical Data
4.14 Undervoltage Protection
SIPROTEC 4, 7UT6x, Manual 449
C53000-G1176-C230-5, Edition 09.2016