ABB RELION Series Technical Manual page 782

Section 13
Protection relay's physical connections
776
To ensure fail-safe operation, the bus is to be biased at one end using the pull-up and
pull-down resistors on the communication module. In the 4-wire connection, the pull-
up and pull-down resistors are selected by setting jumpers X5, X6, X8, X9 to enabled
position. The bus termination is selected by setting jumpers X7, X11 to enabled
position.
The jumpers have been set to no termination and no biasing as default.
Table 721: 2-wire EIA-485 jumper connectors for COM1
Group Jumper connection
X5 1-2
2-3
X6 1-2
2-3
X7 1-2
2-3
1) Default setting
Table 722: 4-wire EIA-485 jumper connectors for COM1
Group Jumper connection
X5 1-2
2-3
X6 1-2
2-3
X7 1-2
2-3
X9 1-2
2-3
X8 1-2
2-3
X11 1-2
2-3
1) Default setting
COM2 port connection can be either EIA-485 or optical ST. Connection type is
selected by setting jumpers X27 and X28.
Table 723: COM2 serial connection X5 EIA-485/ X12 Optical ST
Group
X27
X28
Description
A+ bias enabled
A+ bias disabled
B- bias enabled
B- bias disabled
Bus termination
enabled
Bus termination
1)
disabled
Description
A+ bias enabled
A+ bias disabled
B- bias enabled
B- bias disabled
Bus termination
enabled
Bus termination
1)
disabled
A+ bias enabled
A+ bias disabled
B- bias enabled
B- bias disabled
Bus termination
enabled
Bus termination
1)
disabled
Jumper connection
1-2
2-3
1-2
2-3
1MRS758755 A
Notes
1)
COM1
1)
Rear connector X6
2-wire connection
Notes
1)
COM1
1)
Rear connector X6
4-wire TX channel
1)
1)
4-wire RX channel
Description
EIA-485
Optical ST
EIA-485
Optical ST
REC615 and RER615
Technical Manual