Thytronic SIF5600 - Phase Overcurrent 5051 - Standard Inverse Time Curve (IEC 60255-3 BS142 Type A)

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SIF5600 - Manual - 03 - 2008
Phase overcurrent 50/51 - Standard inverse time curve (IEC 60255-3/BS142 type A)
1.1
2 3 4 5 6 7 8 9 10 20
0.01
0.1
1
10
100
1000
10000
t [s]
t>
dep
= 10.0 s
t>
dep
= 30.0 s
t>
dep
= 60.0 s
t>
dep
= 5.00 s
t>
dep
= 1.00 s
t>
dep
= 0.50 s
t>
dep
= 0.30 s
t>
dep
= 0.10 s
t =
t>
dep
·
[(I/I>
dep
)
0.02
-1]
K
Note: match of operating and setting time takes place when:
I/I>
dep
= 4 for 2.00 fw release (SIF5600-Manual-10-2006” reference document)
I/I>
dep
= 700 for 2.10 and following fw releases
I /I>
dep
K = 0.028 for 2.00 fw release
K = 0.14 for 2.10 and following fw releases