html{display:none} SEL-FT50 and SEL-FR12 Fault Transmitter and Receiver System | Schweitzer Engineering Laboratories

SEL-FT50 and SEL-FR12

Fault Transmitter and Receiver System

The SEL-FT50 and SEL-FR12 System provides an innovative approach for speeding up distribution protection schemes without sacrificing selectivity. You can apply this system with your existing protection schemes to eliminate the need for coordination delays between fuses and protective relays. The system includes line-powered SEL-FT50 Fault Transmitters communicating wirelessly with an SEL-FR12 Fault Receiver over 4 miles. The system communicates the fault data using high-speed Mirrored Bits communications to any SEL device—in less than 6 ms.

Fast detection and communications enable coordination tailored to specific events. This allows you to trip on faults as fast as possible and to selectively decide when reclosing should be enabled, improving safety and reducing wear on equipment. You can install the SEL-FT50 Fault Transmitters on laterals, branches, and the main line to provide additional information for protection decisions. When combined with the SEL-651R Advanced Recloser Control or other SEL distribution protection relays, the SEL-FT50 and SEL-FR12 System makes new protection schemes possible.

Request a Follow-Up


Disable Reclosing for Underground Faults—Knowing whether a fault is on an overhead or underground section of a feeder can be very useful in coordinating reclosing and protection schemes. A set of SEL-FT50 Transmitters can be used to enable reclosing when the fault is on the overhead portion of the feeder.

Tailor Fuse Coordination—Trip fast for main-line faults, and combine fuse-saving and fuse-blowing schemes on the same feeder. You can adapt your coordination based on the SEL-FT50 fault information from laterals, branches, and the main line.

Extend the Range to 20 Miles With SEL-3031 Serial Radio Transceivers—SEL-3031 Radios typically add less than 5 milliseconds of latency for control commands using Mirrored Bits communications.

Visual Overview

Using fault information from the SEL-FT50 Fault Transmitters, the SEL-651R can make faster and more intelligent protection decisions, clearing main-line faults without waiting for fuse coordination on branch circuits or waiting for delay tripping for a fuse-blowing scheme on a lateral. 

FT50-FR12 v6


Adapt Coordination, Fast—SEL-FT50 & SEL-FR12

Watch Video New
Adapt Coordination, Fast—SEL-FT50 & SEL-FR12

Speed Up Distribution Protection—SEL-FT50 & SEL-FR12

Watch Video New
Speed Up Distribution Protection—SEL-FT50 & SEL-FR12

Customize Reclosing for Feeders—SEL-FT50 & SEL-FR12

Watch Video New
Customize Reclosing for Feeders—SEL-FT50 & SEL-FR12

Think Milliseconds, Not Seconds
By providing individual branch inputs, the SEL-FT50 and SEL-FR12 System allows you to engineer faster protection schemes that permit SEL distribution relays or recloser controls to make better decisions about tripping and reclosing. This system is an economical way to improve speed, selectivity, and safety on distribution feeders by providing adaptive coordination for any event.

Reduce Operation and Maintenance Costs
Stretch your budget and get more from your power system assets. Because faults are identified fast, the fault current duration is shortened, reducing operation and maintenance costs by extending the useful life of equipment. Implementing fuse-saving schemes results in fewer truck rolls, fewer fuse replacements, and lower operation costs.

Easy to Deploy, Easy to Maintain
The lightweight design of the SEL-FT50 makes it easy to install by simply using a hot stick to clamp it to the overhead line. The system has just a few settings, all set via control (DIP) switches. In fact, the entire system can be installed and configured without using a computer. The SEL-FT50 is rugged and line-powered, providing maintenance-free operation.

Wireless Area Coverage Study
SEL provides a wireless fault transmitter study free of charge for the planned use of an SEL-FT50 and SEL-FR12 System. You provide location information for the SEL-FR12, and the study identifies viable areas to install SEL-FT50 Transmitters. For larger studies, we offer a service for a fee through SEL Engineering Services.

The SEL-FT50 and SEL-FR12 System is approved for use by the governments of the following countries:

  • Australia
  • Brazil
  • Canada
  • Colombia
  • European Union
  • Mexico
  • New Zealand
  • Peru
  • United States

SEL recommends these parts to go with the SEL-FR12 Receiver and SEL-FT50 Transmitters for specific applications:

SEL-FR12 Recloser Control Accessory Kit

  • SEL-C968-50 Low-Loss LMR-400 N-to-N Connector, 50 ohm, 50 ft*
  • Omnidirectional Antenna
  • 240-0103 Vertical Omnidirectional Antenna Mount for up to 14" Diameter Pole

SEL-FR12 Substation Accessory Kit

  • SEL-C968-75 Low-Loss LMR-400 N-to-N Connector, 50 ohm, 75 ft*
  • SEL-C975-25 RG8-X BNC-to-N Connector, 50 ohm, 25 ft*
  • 200-2004 Radio Surge Protector With N Connectors
  • Omnidirectional Antenna
  • 240-0106 Mast Mount for Omnidirectional Antennas

These parts are available as “recommended accessories.” When you use the Popular Model selector to choose a receiver or transmitter, the accessories are available in the second step of the process.

*Other cable lengths are available

ComplianceDesigned and manufactured under an ISO 9001-certified quality management system
Operating and Storage Temperature Range–40° to +85°C (–40° to +185°F)
Operating EnvironmentPollution degree: 2
Relative humidity: 5–95%, noncondensing
Maximum altitude: 2,000 m
Ingress Protection (SEL-FT50)IP67
Clamp Range (SEL-FT50)0.25” to 1.25”0.3” to 1.1” 

5.58" diameter, 6.97" height

5.71" diameter, 5.83" height

1.72" tall, 9.57" wide, 4.61" deep






Line-powered (no batteries)

Voltage: 9–30 Vdc
Power consumption: <2 W

Power System Frequency Range45–65 Hz
Current Pickup Level

Units individually configurable: 50, 100, 200, 400, 600, 800, 1,000, and 1,200 A

Fault Detection Accuracy3% typical, 20% maximum20% typical
Maximum VoltageUp to 38 kV (L-L)
LatencyFault detection (SEL-FT50) to Mirrored Bits communications output (SEL-FR12): 6 ms
Network Size12 SEL-FT50 Transmitters per SEL-FR12 Receiver
16 customer-selectable network IDs
ISM Frequency Band

902–928 MHz for United States, Canada, and Colombia
916–928 MHz for Peru

TX power: 30 dBm 

902–928 MHz for Mexico
902–907.5 and 915–928 MHz for Brazil
915–928 MHz for Australia and New Zealand
863–870 MHz for European Union 

TX power: 30 dBm (21 dBm for Australia and New Zealand, 16 dBm for European Union)  

Number of channels: 12

RX sensitivity: –97 dBm (–105 dBm for Australia, New Zealand, and European Union) at 1% packet error rate (PER)

Serial protocol: Mirrored Bits communications

Serial port: 9,600, 19,200, 38,400, 115,200 bps

Typical Range4 miles with 20 dB fade margin 4 miles with 20 dB fade margin (2 miles for European Union) 


Patents pending


Documents sorted by newest first.


Sales Force Central access is required to view the content in this tab.

Sales Force Central

The Firmware IDs for older versions of the firmware can typically be found in Appendix A of the instruction manual.