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3 - 6
Siemens AG ⋅ January 1999
Table 3.6 Line differential protection
Current threshold I
1
(release with local current)
I/I
N line
Differential current I/I
N line
Delay time T
0.00 to 1.50 (step 0.01)
0.05 to 2.50 (step 0.01)
0.00 to 60.00 s (step 0.01 s)
Stabilization with 2nd harmonic I
2fN
/I
fN
Resetting ratio
see Figure 3.1
10 to 80 %
approx. 0.7 @ pick-up value (I
stab
=0)
All current values refer to symmetrical current with standard connection.
Pick-up time for two-sided infeed
with 4 x setting value
Reset time
approx. 20 to 28 ms without stabilization by
2 harm
approx. 32 to 42 ms with stabilization by
2 harm
approx. 35 ms
with pre-settings
under reference conditions
Local current threshold
Differential current
"3 % of set value, min 0.02 @ I
N
"5 % of set value, min 0.02 @ I
N
Auxiliary supply voltage in range
0.8
v U
H
/U
HN
v@1.15
Temperature in range 0 _C
v
amb
v 40 _C
Frequency in range 0.9
v f/f
N
v 1.1
v1%
v1 %/10K
v4%
Number
Asymmetry of pilot wire pair at 800 Hz
Maximum loop resistance
Permissible induced longitudinal voltages
for direct connection with pilot wire
for connection via isolating transformer
2
preferably symmetrical telephone wire pairs
with 73 /km loop resistance and 60 nF/km
capacitance
max. 10
-3
1200
v1.2 kV, but max. 60 % of the test voltage of
the pilot wires
w1.2 kV, but max. 60 % of the test voltage of
the pilot wires and max. 60 % of the test volĆ
tage of the isolating transformer
(order option)
Monitoring signal
Delay of fail signal
Operating time of transfer tripping
Prologation of transfer trip signal
2000 Hz, pulse code modulation
1 to 60 s (step 1 s)
approx. 65 ms
0.00 to 5.00 s (step 0.01 s)
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