Manual

3-44 Protection Functions
865-UM001A-EN-P – July 2009
Equation 10 – RXIDG
pickup
RXIDG
Ik
I
t ln35.18.5 −=
t = Operation delay in seconds
k = User’s multiplier
I = Measured value
I
pickup
= User’s pick up setting
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 3.30.
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 3.31.