ABB RELION REF615R, Technical Manual

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Table 449: 2-wire EIA-485 jumper connectors
Group Jumper connection Description Notes
X4 1-2 A+ bias enabled COM2
2-wire connection
2-3 A+ bias disabled
X5 1-2 B- bias enabled
2-3 B- bias disabled
X6 1-2 Bus termination enabled
2-3 Bus termination disabled
X7 1-2 B- bias enabled COM1
2-wire connection
2-3 B- bias disabled
X8 1-2 A+ bias enabled
2-3 A+ bias disabled
X9 1-2 Bus termination enabled
2-3 Bus termination disabled
The bus is to be biased at one end to ensure fail-safe operation, which can be done using
the pull-up and pull-down resistors on the communication module. In 4-wire connection
the pull-up and pull-down resistors are selected by setting jumpers X4, X5, X7 and X8 to
enabled position. The bus termination is selected by setting jumpers X6 and X9 to enabled
position.
The jumpers have been set to no termination and no biasing as default.
Table 450: 4-wire EIA-485 jumper connectors for COM2
Group Jumper connection Description Notes
X4
1-2 A+ bias enabled
COM2
4-wire TX channel
2-3
A+ bias disabled
1)
X5
1-2 B- bias enabled
2-3
B- bias disabled
1)
X6
1-2 Bus termination enabled
2-3
Bus termination disabled
1)
X7
1-2 B- bias enabled
COM2
4-wire RX channel
2-3
B- bias disabled
1)
X8
1-2 A+ bias enabled
2-3
A+ bias disabled
1)
X9
1-2 Bus termination enabled
2-3
Bus termination disabled
1)
1) Default setting
1MRS240050-IB C
Section 14
Protection relay's physical connections
REF615R 633
Technical Manual