[fo_UVP3ph_inverse, 2, en_US]
Where
T
Inv
Inverse-time delay
T
p
Time multiplier (parameter Time dial)
V Measured undervoltage
V
Thresh
Threshold value (parameter Threshold)
k Curve constant k (parameter Charact. constant k)
α Curve constant α (parameter Charact. constant α)
c Curve constant c (parameter Charact. constant c)
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
Pickup time
Approx. 25 ms + OOT
34
at 50 Hz
Approx. 22 ms + OOT at 60 Hz
Dropout time Approx. 20 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 ≤ 80 Hz
Slightly expanded tolerances
f < 10 Hz
f > 80 Hz
Inactive, maintained;
Dropout of the pickup induced by blocking or by
increasing the measurand beyond the dropout
threshold
Tolerances for Stage Type Definite-Time Undervoltage Protection
Voltages
0.5 % of the setting value or 0.05 V
Currents 1 % of the setting value or 5 mA (I
rated
= 1 A) or 25 mA
(I
rated
= 5 A, f
rated
± 10 %), valid for protection-class
current transformers
1 % of the setting value or 0.1 mA (I
rated
= 1.6 A) or
0.5 mA (I
rated
= 8 A, f
rated
± 10 %), valid for instrument
transformers
Time delays 1 % of the setting value or 10 ms
34
OOT (Output Operating Time): additional delay of the output medium used, see Chapter 12.1.4 Relay Outputs
Technical Data
12.7 Undervoltage Protection with 3-Phase Voltage
728 SIPROTEC 5, Paralleling Device, Manual
C53000-H5040-C071-1, Edition 05.2018
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