Siemens siprotec 7SD610 User Manual page 137

Figure 2-51
2 Protection Relays If redundant protection is provided for a line and each protection operates with its own
with 2 Automatic automatic reclosure function, a certain signal exchange between the two combinations
Reclosure Circuits is necessary. The connection example in Figure 2-52 shows the necessary cross-con-
nections.
If phase segregated auxiliary contacts of the circuit breaker are connected, a three-
pole coupling by the 7SD610 is ensured when more than one CB pole is tripped. This
requires activation of the forced three-pole trip (see Section 2.10.2 at margin heading
„Forced three-pole trip"). An external automatic three-pole coupling is therefore un-
necessary if the above conditions are met. This prevents two-pole tripping under all
circumstances.
7SD610 Manual
C53000-G1176-C145-4
Connection example with external protection device for fault detection depen-
dent dead time — dead time control by pickup signals of the protection device;
AR control mode = with PICKUP
2.10 Automatic Reclosure Function (optional)
137