5
Date Code 20210405
Instruction Manual
SEL-FT50/SEL-FR12 Fault Transmitter and Receiver System
System Overview
Each SEL-FT50 mounts onto and monitors the line current on one phase. When a
fault occurs, the SEL-FT50 transmits a high-speed wireless signal to influence
protection decisions. Control (DIP) switches inside the transmitter allow easy
selection of unit and Network IDs. No batteries are needed because the
SEL-FT50 is powered by line current.
In applications where trees, buildings, or terrain could block the line-of-sight
path between the SEL-FT50 and SEL-FR12 antenna, one or more SEL-RP50
Fault Repeaters can be installed to forward signals that might otherwise be
blocked.
Figure 4
shows the exterior and interior features of the SEL-RP50.
Each SEL-RP50 mounts onto and harvests energy from one phase. The
SEL-RP50 Unit ID and Network ID DIP switch selections must be set the same
as the companion SEL-FT50 or SEL-RP50s, and mounted on the same electrical
phase. Like the SEL-FT50, for three-phase systems the SEL-RP50s will normally
be installed in groups of three. Up to five SEL-RP50 (sites) may be used for each
SEL-FT50 with appropriate Repeater ID selections. See
Technical Support on
page 57
for details and examples on SEL-RP50 deployment. No batteries are
needed because the SEL-RP50 is powered by line current. Each SEL-RP50 site
typically adds up to 1 ms to the fault response time as seen by the SEL-FR12.
Figure 4
SEL-RP50 Overview
Shotgun stick loop
Current transformer
Twistlock housing
for setting access
Omnidirectional antenna for
the radio receiver and transmitter
Left control (DIP)
switch bank
SW 1–4 Unit ID
SW 5–8 Network ID
Right control (DIP)
switch bank
SW 1–3 Repeater ID
Conductor stop
Spring for secure installation
NOTE:
The SEL-RP50 is a node in
the wireless link between the
SEL-FT50 and the SEL-FR12. The
SEL-RP50 receives fault and link
messages, modifies the message by
attaching identifier and diagnostic
data, then transmits this message to
the next device in the link (e.g.,
another SEL-RP50 or SEL-FR12).
