Undervoltage Protection with Any Voltage
Setting Values
Measured value
Measured phase-to-ground voltage V
A
Measured phase-to-ground voltage V
B
Measured phase-to-ground voltage V
C
Measured phase-to-phase voltage V
AB
Measured phase-to-phase voltage V
BC
Measured phase-to-phase voltage V
CA
Calculated phase-to-phase voltage V
AB
Calculated phase-to-phase voltage V
BC
Calculated phase-to-phase voltage V
CA
Calculated voltage V0
Method of measurement
Fundamental component
RMS value
Threshold value
60
0.300 V to 340.000 V
Increments of 0.001 V
Time delay
0.00 s to 60.00 s
Increments of 0.01 s
Dropout ratio
1.01 to 1.20
Increments of 0.01
Dropout
The greater dropout differential (=
| pickup value – dropout value |
) of the following 2 criteria
applies:
Dropout differential derived from the parameter
Dropout ratio
If this parameter is not available, a dropout ratio of 95 % applies for the overvoltage and of 105 % for the
undervoltage functionality.
Minimum absolute dropout differential
150 mV sec.
Times
Operate time with time delay = 0 ms, typical
Approx. 25 ms + OOT
61
at 50 Hz
Approx. 22 ms + OOT at 60 Hz
Operate time with time delay = 0 ms, maximum
Approx. 30 ms + OOT at 50 Hz
Approx. 26 ms + OOT at 60 Hz
Dropout time, typical
Approx. 25 ms + OOT
Dropout time, maximum
Approx. 30 ms + OOT
Frequency Operating Range
0.9 ≤ f/f
rated
≤ 1.1
According to specified tolerances
10 Hz ≤ f < 0.9 f
rated
1.1 f
rated
< f ≤ 90 Hz
Slightly expanded tolerances
f < 10 Hz
f > 90 Hz
Inactive, maintained;
Dropout of the pickup induced by blocking or by increasing the
measurand beyond the dropout threshold
11.19.8
60
If you have selected the method of measurement = RMS value, do not set the threshold value under 10 V.
61
OOT (Output Operating Time): additional delay of the output medium used, see Chapter
Technical Data
11.19 Voltage Protection
SIPROTEC 5, Low-Impedance Busbar Protection, Manual
965
C53000-G5040-C019-C, Edition 04.2021
