User's Manual

15
Date Code 20170317 Instruction Manual SEL-FT50/SEL-FR12 Fault Transmitter and Receiver System
System Installation
Figure 13 Serial Port Settings Selection
Setting Near/Distant SEL-FT50
For three-phase installations, the SEL-FT50 Fault Transmitters are installed in
groups of three, and the received signal strength from all members of a trio is
identical. The received signal strength between multiple trios is usually
different because of path differences. To accommodate the range of reception
signal strengths, an attenuation setting is provided for each trio. See Table 3
for trio assignments.
NOTE: There is no transmitter power
adjustment selection in the SEL-FT50.
The appropriate attenuation setting for each trio is based on the distance
between the trio and the SEL-FR12.
Figure 14 Trio Attenuation Switch Selection
Connecting the SEL-FR12 to Other SEL Devices
The SEL-FR12 uses the MB8 MIRRORED BITS protocol.
The following
examples give sample configurations for SEL devices that operate with the
SEL-FR12. For each of these examples, select BAUD = 38400, RX_ADD = 2,
and TX_ADD = 1 on the SEL-FR12. Only the minimum settings required are
shown. Consult the appropriate instruction manual to ensure proper settings
for your particular M
IRRORED BITS application.
Table 3 Trio Assignments
Node (Three-Phase) Unit ID Assignments at Each Location Trio Number
1 1, 2, 3 1
2 4, 5, 6 2
3 7, 8, 9 3
4 10, 11, 12 4