31
Date Code 20210405
Instruction Manual
SEL-FT50/SEL-FR12 Fault Transmitter and Receiver System
Device Installation
The SEL-FT50 only reads settings during startup; changing settings while the
unit is turned on has no effect. Changing settings requires removal of device
power. The SEL-FT50 retains some energy in storage and may take a couple of
minutes to fully turn off. For an SEL-FT50 connected to an SEL-FR12, the
device is fully turned off when the
LINK
LED for that unit starts blinking, indicat-
ing that the receiver has stopped receiving link messages from the SEL-FT50
transmitter.
To begin, open the SEL-FT50 by twisting the bottom counter-clockwise. On the
inside of the device, you will see the two banks of switches. The switch positions
are labeled 1 through 8 on each of the two switch banks. The switch selections
are outlined on a label on the interior of the device, as shown in
Figure 21
.
Setting the Unit ID
The SEL-FR12 Fault Receiver receives wireless signals from as many as 12
SEL-FT50 Fault Transmitters on the same network, defined by the Network ID
selection in the SEL-FT50/SEL-FR12 system.
To allow the SEL-FR12 to distinguish which fault transmitter has sent a message,
each SEL-FT50 transmits a Unit ID field as part of the message (the Unit ID is a
number from 1 to 12).
The following lists the requirements when planning the Unit IDs to use in a sys-
tem:
➤
Unit IDs cannot be duplicated on the network.
➤
Not all Unit IDs need to be present.
➤
Unit IDs should be grouped in three-phase locations as trios (see
Table 4
).
➤
Single-phase and two-phase applications are possible in specific situ-
ations.
➤
Unit IDs should be marked on the system record for later installation
and commissioning work.
➤
Each SEL-FT50 Unit ID is configurable and is selected by the Unit
ID control switches inside the housing.
Figure 21
SEL-FT50 Switch Selections Labels
CAUTION
To avoid damaging the SEL-FT50, do
not use the CT and clamping mecha-
nism as a handle when removing the
bottom.
NOTE:
Each SEL-FT50 transmits
faults on a specific frequency based
on its Unit ID, and the frequencies for
each Unit ID are the same across
different networks. To avoid collisions,
select the Unit ID such that a single
fault is not likely to trip two SEL-FT50
Fault Transmitters (with the same Unit
ID) on separate networks.
For example, consider an SEL-FT50
with Unit ID 1 on Phase A of a given
feeder. If you have a separate network
downstream, assigning Unit ID 1 to an
SEL-FT50 on Phase A on that
separate network would result in a
Phase-A line fault tripping both
SEL-FT50 Fault Transmitters
simultaneously.
