Siemens 7SK80 Manual page 303

Setting Group Change Function
If binary inputs are used to switch setting groups, please observe the following:
• Two binary inputs must be dedicated to the purpose of changing setting groups when four groups are to be
switched. One binary input must be set for „>Set Group Bit0", the other input for „>Set Group Bit1".
If either of these input functions is not assigned, then it is considered as not controlled.
• For the control of 2 setting groups one binary input is sufficient, namely „>Set Group Bit0", since the
non-assigned binary input „>Set Group Bit1" is then regarded as not connected.
• The control signals must be permanently active so that the selected setting group is and remains active.
The following table shows the allocation of the binary inputs to the setting groups A to D and a simplified con-
nection diagram for the two binary inputs is illustrated in the following figure. The figure illustrates an example
in which both Set Group Bits 0 and 1 are configured to be controlled (actuated) when the associated binary
input is energized (high).
Where:
no =
yes =
Table 3-1
>Set Group Bit 0
No
Yes
No
Yes
Figure 3-1
Trip Circuit Supervision
Please note that two binary inputs or one binary input and one bypass resistor R must be connected in series.
The pick-up threshold of the binary inputs must therefore stay substantially below half the rated control DC volt-
age.
If one binary input is used, a bypass resistor R must be used (see following figure). The resistor R is inserted
into the circuit of the 52b circuit breaker auxiliary contact to facilitate the detection of a malfunction also when
the 52a circuit breaker auxiliary contact is open and the trip contact has dropped out. The value of this resistor
must be such that in the circuit breaker open condition (therefore 52a is open and 52b is closed), the circuit
breaker trip coil (52TC) is no longer energized and binary input (BI1) is still energized if the command relay
contact is open.
SIPROTEC, 7SK80, Manual
E50417-G1140-C344-A5, Release date 11.2012
not energized or not connected
energized
Changing setting groups using binary inputs
Binary Input
>Set Group Bit 1
No
No
Yes
Yes
Connection diagram (example) for setting group switching using binary inputs
Active Group
Group A
Group B
Group C
Group D
Mounting and Commissioning
3.1 Mounting and Connections
303