VAMP 265 - 9.3. Protection Functions; 9.3.1. Differential Protection

Technical description
9 Technical data
9.3 Protection functions
VM265.EN011
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207
9.3. Protection functions
9.3.1. Differential protection
Differential overcurrent stage I> (87)
Setting range
5 - 50 % I
n
Bias current for start of slope 1
0.50 x I
n
Slope 1
5 - 100 %
Bias current for start of slope 2
1.00 - 3.00 x I
n
Slope 2
100 - 200 %
Second harmonic blocking
5 - 30 %, or disable
Reset time
< 95 ms
Reset ratio
0.95
Inaccuracy:
- 2
nd
harmonic blocking
±1% - unit
- Starting
±3% of set value or 0.02 x I
n
when currents are
> 200 mA
- Operating time (I
d
> 1.2 x I
set
)
< 60 ms
- Operating time (I
d
> 3.5 x I
set
)
< 50 ms
NOTE! The amplitude of second harmonic content has to be at least 2% of the
nominal of CT. If the moninal current is 5 A, the 100 Hz component needs
to exceed 100 mA.
Differential overcurrent stage I>> (87)
Setting range
5.0 - 40.0 x I
n
Reset time
< 95 ms
Reset ratio
0.95
Inaccuracy:
- Starting
±3% of set value or ±0.5% of rated value
- Operating time (I
d
> 3.5 x I
set
)
< 40 ms