GE C70 Instruction Manual page 437

8 THEORY OF OPERATION
Equation 8.67 becomes:
Equation 8.68 becomes:
Note that in the ungrounded case, the operating signal is half of that for the grounded case.
• With the grounded configuration, the two banks must be nominally identical. With the ungrounded configuration the
two banks need not be the identical though each should be balanced. In this situation, the base for C(pu) is the
capacitance of the string which has the element failure, so the larger bank will have a lower sensitivity than the smaller
bank.
GE Multilin

C C
d +
A1
------------- - I ----------------------------------------------- - I
=
OP
dC

C
A1
A1
C I
A2
----------------------------------
=

C C
+
A1
I
1
A
 ----  --------- -
4 C
A1
I
A
  ---- 
I pu
=
OP
4
I
rated
 
--------------- -
I pu
=
OP
4I
base
C70 Capacitor Bank Protection and Control System
 C
–
A2 A1
A
2

C
+
A2
A
2

A2
  
C pu
   
C pu
8.1 OVERVIEW
(EQ 8.70)
(EQ 8.71)
(EQ 8.72)
8
8-17