1MRS750886-MUM
25
REU 513
User’s Guide
ABB Substation Automation
Products and Systems
Selector switchgroups SGF, SGB and SGR
Part of the settings and the selections of the operation characteristics of the relay in
various applications is made with selector switchgroups SG_. The switchgroups are
software based and thus not physical switches to be found in the hardware of the
relay. The switches can be set one by one.
A checksum is used for verifying that the switches have been properly set. The
figure below shows an example of manual checksum calculation.
Fig. 2.1.3.6.-1 An example of calculating the checksum of a selector switchgroup
SG_
When the checksum, calculated according to the example above, equals the
checksum read from the relay, the switches in the concerned switchgroup are
properly set.
The following tables indicate the factory default settings of the switches and the
corresponding checksums.
Switch
No
Position
Weighting
factor
Value
1
1
x
1
=
1
2
0
x
2
=
0
3
1
x
4
=
4
4
0
x
8
=
0
5
1
x
16
=
16
6
0
x
32
=
0
7
1
x
64
=
64
8
0
x
128
=
0
Checksum
SG_
∑
=
85