4.10 Undervoltage Protection (ANSI 27)
323
7UM61 Manual
C53000-G1176-C127-3
4.10 Undervoltage Protection (ANSI 27)
Setting Ranges / Increments
Operating Times
Tolerances
Influencing Variables
Measured Quantity Positive Sequence phase-to-earth voltages as
phase-to-phase values
Pickup thresholds U, U<<, Up< 10.0 V to 125.0 V Increments 0.1V
Dropout ratio RV U<
(only stages U<, U<<)
1.01 to 1.20 Increments 0.01
Time Delays T U<, T U<< 0.00 s to 60.00 s
or ∞ (ineffective)
Increments 0.01 s
The set times are pure delay times.
Pickup Times approx. 50 ms
Dropout Times approx. 50 ms
Pickup voltages U<, U<< 1 % of setting value or 0.5 V
Delay times T 1 % of setting value or 10 ms
Auxiliary DC voltage in range
0.8 ≤ U
Aux
/U
AuxN
≤ 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 %
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