Siemens SIPROTEC 7UT613 series Manual page 439

Operating Times (Generators, Motors, Reactors)
Operating Range Frequency (Generators, Motors, Reactors)
Differential Current Monitor (Busbars, Short Lines)
7UT613/63x Manual
C53000-G1176-C160-2
Pickup time / dropout time with single-side infeed
Pickup time at frequency
I high-speed relays
> min
Diff
high-speed relays
high-speed relays
I
>> min
Diff
high-speed relays
Dropout time, approx.
Dropout ratio
Frequency influence within the frequency tagging range
Figure 4-5 Frequency influence (generator / motor protection and busbar protection)
I
differential current = |I
diff
I
Nominal current of protected object
NObj
I
Current at any frequency within specified range
Xf
Note:
Higher tolerances must be expected if I
transformers). Also, the device tolerances do not include measuring errors originating from
summation CTs and magnetizing currents.
Steady-state differential current monitoring
I
/I
Monit NObj
50 Hz
30 ms
25 ms
11 ms
6 ms
54 ms
approx. 0.7
+ I
|
1 2
= 0.1 A (device connected via summation current
N
0.15 to 0.80
4.2 Differential Protection
60 Hz 16.7 Hz
27 ms 78 ms
22 ms 73 ms
11 ms 20 ms
6 ms 15 ms
46 ms 150 ms
see Figure 4-5
Steps 0.01
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