Siemens SIPROTEC 4 7UT6 Series Manual page 412

Technical Data
4.2 Differential Protection
Operating Range Frequency (Generators, Motors, Reactors)
Frequency influence within the frequency tagging range
[tdfrequenzeinf-genmot-7ut612-021026-rei, 1, en_GB]
Figure 4-5
Idiff Differential current = |Ι
INObj Nominal current of protected object
IXf Current at any frequency within specified range
Differential Current Monitor (Busbars, Short Lines)
Note:
Higher tolerances must be expected if Ι
transformers). Also, the device tolerances do not include measuring errors originating from
summation CTs and magnetizing currents.
Steady-state differential current monitoring
/Ι
Ι
Monit NObj
Delay of blocking of differential current
T
Monit
Feeder Current Guard (Busbars, Short Lines)
Trip release by feeder current guard
Operating Time (Busbars, Short Lines)
7UT612
Pickup time / dropout time with single-side infeed
Pickup time at frequency
412
Frequency influence (generator / motor protection and busbar protection)
+ Ι |
1 2
= 0.1 A (device connected via summation current
N
0.15 to 0.80
1 s to 10 s
/Ι 0.20 to 2.00
Ι>
Guard NObj
or 0 (always
released)
50 Hz 60 Hz
see Figure 4-5
Increments 0.01
Increments 1 s
Increments 0.01
SIPROTEC 4, 7UT6x, Manual
C53000-G1176-C230-5, Edition 09.2016