Siemens 7PG21 Solkor Rf - Figure 10 through Fault Rf Mode, Positive Half Cycle

7PG21 Solkor Rf Description of Operation
A
X
B
C
X
Y
W
Z
D
O
P
D3
R
a
D4
Y
R
p
+
-
D2
D
-
+
W Z
C
B
A
D5
+
-
-
+
O
P
R
a
D7
D8
Figure 10 Through fault Rf mode, positive half cycle
Figure 11 Through fault Rf mode, positive half cycle
If the condition of zero pilots is then considered for Solkor Rf (i.e. with 1000 ohms padding in each relay), the
circuit and voltage distribution are as shown in Figure 10 & Figure 11. This shows that the same bias voltages are
as obtained in Figure 8 & Figure 9.
©2011 Siemens Protection Devices Limited Chapter 1 Page 10 of 13