7PG21 Solkor Rf Description of Operation
B
C
A
X
Y
W
Z
D
D3
Ra
D4
X
Y
Rp
+
-
D2
D
-
+
W
Z
C
B
A
Rp
Figure 6 Through Fault, 1000 ohm pilots, Positive half cycle.
D4
R a
D3
Y
X
R
p
+
-
D1
A
-
+
Z
W
B
C
D
R
p
C
B
D
Y
X
Z
W
A
Figure 7 Through Fault, 1000 ohm pilots, Positive half cycle.
At the other limiting condition the pilot resistance is a 1000 ohms loop and the circuit will be as shown in Figure 6
& Figure 7. with 500 ohms in each leg of the pilot circuit and zero padding resistors. As shown in Figure 6 &
Figure 7 the resultant voltage distribution of this maximum pilot arrangement gives identical voltages across the
relay points B-X and C-Y.
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Chapter 1 Page 8 of 13
