Siemens 6MD85 Manual page 1156

Technical Data
11.20 Undervoltage Protection with 3-Phase Voltage
[fo_UVP3ph_inverse, 2, en_US]
Where
T Inverse-time delay
Inv
T Time multiplier (parameter Time dial)
p
V Measured undervoltage
V Threshold value (parameter Threshold)
Thresh
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
Times
Pickup time
Dropout time
Frequency Operating Range
0.9 ≤ f/f ≤ 1.1
rated
10 Hz ≤ f < 0.9 f
1.1 f < f ≤ 80 Hz
rated
f < 10 Hz
f > 80 Hz
Tolerances for Stage Type Definite-Time Undervoltage Protection
Voltages
Currents
Time delays
76 OOT (Output Operating Time): additional delay of the output medium used, see Chapter
1156
rated
150 mV sec.
Approx. 25 ms + OOT at 50 Hz
76
Approx. 22 ms + OOT at 60 Hz
Approx. 20 ms + OOT
According to specified tolerances
Slightly expanded tolerances
Inactive, maintained;
Dropout of the pickup induced by blocking or by
increasing the measurand beyond the dropout
threshold
0.5 % of the setting value or 0.05 V
1 % of the setting value or 5 mA (I
(I = 5 A, f ± 10 %), valid for protection-class
rated rated
current transformers
1 % of the setting value or 0.1 mA (I
0.5 mA (I = 8 A, f ± 10 %), valid for instrument
rated rated
transformers
1 % of the setting value or 10 ms
11.1.4 Relay Outputs
SIPROTEC 5, High-Voltage Bay Controller, Manual
C53000-G5040-C015-9, Edition 11.2017
= 1 A) or 25 mA
rated
= 1.6 A) or
rated