User's Manual

5
Date Code 20170317 Instruction Manual SEL-FT50/SEL-FR12 Fault Transmitter and Receiver System
Application Examples
➤ The ROK, TX, RX (green), and LOOP (red) LEDs indicate
MIRRORED BITS status and activity. The ROK LED illuminates
when MIRRORED BITS data exchange is successful.
➤ The TARGET RESET pushbutton resets the FAULT LEDs. Press and
hold the pushbutton to illuminate all HMI LEDs (lamp test
function).
Application Examples
Collect Fault
Information From
Remote Branches
A traditional recloser control or substation circuit breaker must be coordinated
with the other protective devices on a distribution feeder, including fuses on
downstream line segments. On the sample feeder in Figure 4, the recloser
control or substation relay cannot distinguish one segment from another.
Figure 4 Typical Recloser Visibility
The SEL-FT50/SEL-FR12 system offers increased visibility to a recloser
control by providing fault status from locations as far away as two miles.
Figure 5 illustrates how this allows the recloser control to see faults on
individual branches, including locations where it is not economically feasible
to install a relay or recloser. Each SEL-FT50 label in Figure 5 represents three
SEL-FT50 Fault Transmitters, one per phase.
Table 1 Target and Status LED Definitions
LED (Color) Off Flashing On Reset Methods
FAULT (red) target No fault signal has been
received from the
corresponding Unit ID
since the last reset.
Not applicable. The SEL-FR12 received a
fault signal from the cor-
responding Unit ID since
the last reset.
Manual—resets via the
TARGET RESET pushbutton.
Remote—resets via MIR-
RORED BITS.
LINK (green) status The SEL-FR12 has not
detected an SEL-FT50
with the corresponding
Unit ID since initializa-
tion.
This learning feature
keeps unused LINK LEDs
turned off.
The SEL-FR12 is not
presently receiving sig-
nals from the previously
learned Unit ID, indicat-
ing that an SEL-FT50 is
not harvesting energy
during low-current condi-
tions or an outage.
The SEL-FR12 has
received signals from the
corresponding Unit ID
within the last minute,
indicating that the
SEL-FT50 is receiving
minimum radio link active
current.
Automatic—learning
mode resets automatically
after the SEL-FR12 turns
on.
Remote—resets via M
IR-
RORED BITS.
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