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98
Two step definite and inverse time
delayed phase overcurrent protection
(TOC2)
I
S EC
⋅
------------- - Is
Is
=
SEC
I
PRIM
where I
is the secondary rated current of the main CT and I
SEC
current of the main CT.
The relay setting value for I>Inv, I>Low and I>High is given in percentage of the sec-
ondary base current value, I
is given from the formula:
Is
SE C
⋅
I
=
-------------- - 100
set
I
1b
, associated to the current transformer input I1. The value
1b
&KDSWHU
&XUUHQW
(Equation 45)
is the primary rated
PRIM
(Equation 46)
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