Instruction Manual

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Date Code 20210405 Instruction Manual SEL-FT50/SEL-FR12 Fault Transmitter and Receiver System
Network Deployment Overview
If an alternative SEL-FT50 site is not available, consider whether the SEL-FR12
location could be moved to another point with better line of sight. Use the
SEL-3031 as a backhaul device to carry the data back to the relay or recloser con-
trol that needs the fault information, as shown in Figure 16.
Path Study
A path study, rather than an area study, can be performed for networks with only
a few SEL-FT50 devices that have either a long link range or have obstructions in
the link path. A path study can also complement an area study for specific links
in a larger network where received signal level is not optimal. Performing a path
study helps you understand the propagation characteristics of the link and
whether reliable communication is achievable. SEL provides radio path studies
for as many as five SEL-FT50 links at no cost. For larger studies, SEL offers this
service, as well as link planning and testing, for a fee through SEL Engineering
Services, Inc. (contact SEL for details). Only one path study is needed for each
group of collocated SEL-FT50 devices.
On-Site Testing
SEL-FR12 Installation
Install the network SEL-FR12 at the identified site or set of sites and enable the
radio before installing any SEL-FT50 devices. Follow the procedures in Physical
Installation on page 35 for instructions on the physical installation. Commission
the SEL-FR12 as described in Commissioning the SEL-FR12 on page 23.
Verify the radio is enabled and functioning with a nearby SEL-FT50 device. For
this test, use the SEL-FT50 with a mini current loop to test the link. Simulate a
fault by using the mini current loop and verify that the device registers a fault on
the SEL-FR12 front-panel LEDs. The RSSI information available will indicate
the signal strength, verifying RF connectivity and initial SEL-FR12 setup. See
Receive Signal Strength Indicator on page 26 for details. Now you are ready to
install SEL-FT50 devices on the distribution system.
Figure 16 Using the SEL-3031 as a Repeater for Links Without a Clear Line of
Sight
Obstruction
SEL-FT50
Location
>15 dB Link Margin
<15 dB Link Margin
Relay or Recloser
Control Used in
SEL-FT50/SEL-FR12
Application
SEL-FR12 and SEL-3031
Repeater Site
NOTE: After installing the SEL-FT50
on the Mini Current Loop, press the
button on the loop to simulate a fault.
You should see a FAULT LED on the
SEL-FR12 right away. The LINK LED will
illuminate within 80 s if more than
one fault is triggered.