7PG2113/4/5/6 Solkor 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 3.2-3 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 3.2-4 Through Fault, 1000 ohm pilots, Negative half cycle.
At the other limiting condition the pilot resistance is a 1000 ohms loop and the circuit will be as shown in Figure
3.2-3 & Figure 3.2-4. with 500 ohms in each leg of the pilot circuit and zero padding resistors. As shown in Figure
3.2-3 & Figure 3.2-4 the resultant voltage distribution of this maximum pilot arrangement gives identical voltages
across the relay points B-X and C-Y.
©2010 Siemens Protection Devices Limited Chapter 1 Page 29 of 80