VAMP 259 - Page 142

2.24 Inverse time operation
2 Protection functions
Technical description
142
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VM259.EN007
Example for Delay type RI :
k = 0.50
I = 4 pu
I
pickup
= 2 pu
3.2
2
4
236.0
339.0
5.0









RI
t
The operation time in this example will be 2.3 seconds. The
same result can be read from Figure 2.24.1-15.
Example for Delay type RXIDG:
k = 0.50
I = 4 pu
I
pickup
= 2 pu
9.3
25.0
4
ln35.18.5 


RXIDG
t
The operation time in this example will be 3.9 seconds. The
same result can be read from Figure 2.24.1-16.
Figure 2.24.1-15 Inverse delay of
type RI.
Figure 2.24.1-16 Inverse delay of
type RXIDG.