User's Manual

SEL-FT50/SEL-FR12 Fault Transmitter and Receiver System Instruction Manual Date Code 20170317

Application Examples

Figure 5 Recloser Communication With Fault Transmitters

Each SEL-FT50 monitors line current and instantly transmits a wireless signal

when an overcurrent (fault) condition occurs. The companion SEL-FR12

receives and aggregates fault data from as many as 12 SEL-FT50 Fault

Transmitters. Upon detecting a fault indication signal, the SEL-FR12

communicates the fault information to the host SEL-651R recloser control, or

other SEL protective relay, by using M

IRRORED BITS communications.

The SEL-FT50/SEL-FR12 system allows the protective relay or recloser

control to make intelligent decisions by using high-speed fault information

from remote locations.

Improve Fuse

Coordination

In a radial distribution system, there are two main schemes that control fuse

coordination: fuse-saving and fuse-blowing (also called trip-saving). Each of

these schemes has shortcomings that you can address with the

SEL-FT50/SEL-FR12 system.

Figure 6 gives a representation of a typical time-overcurrent coordination

graph.

Wireless

SEL-FT50

SEL-FR12

SEL-651R-2