User's Manual

2
SEL-FT50/SEL-FR12 Fault Transmitter and Receiver System Instruction Manual Date Code 20170317
Functional Overview
Functional Overview
The SEL-FT50/SEL-FR12 system consists of as many as twelve SEL-FT50
Fault Transmitters and one SEL-FR12 Fault Receiver. The SEL-FT50 is mounted
on distribution conductors with voltages as high as 38 kV. The SEL-FR12 is
mounted in a recloser control cabinet or in a substation control house.
When one or more SEL-FT50 Fault Transmitters detect a fault, they send a
wireless signal to the SEL-FR12. The SEL-FR12 transfers the received signal
to the recloser control or relay via MIRRORED BITS communications in as little
as 6 ms. The recloser control uses the fault information to make protection or
relay decisions.
To monitor the health of the system, the SEL-FT50 Fault Transmitters
periodically send communication link-check messages to the SEL-FR12 to
indicate their status.
System Overview
Figure 1 provides an overview of the SEL-FT50/SEL-FR12 system and
illustrates how to apply it across a distribution power system.
Serial Port
MIRRORED BITS
Encoder
12-Channel
Receiver
SEL-FR12 Fault Receiver
Receive
MIRRORED BITS Output
Overhead Conductor
SEL-FT50 Fault Transmitter
Signal and
Energy Harvest
Fault
Sense
Link-Check
Timer
Power
Circuit
Radio
Transmit