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.
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.
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.
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:
SEL recommends these parts to go with the SEL-FR12 Receiver and SEL-FT50 Transmitters for specific applications:
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
|Compliance||Designed and manufactured under an ISO 9001-certified quality management system|
|Operating and Storage Temperature Range||–40° to +85°C (–40° to +185°F)|
|Operating Environment||Pollution 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 System Frequency Range||45–65 Hz|
|Current Pickup Level|
Units individually configurable: 50, 100, 200, 400, 600, 800, 1,000, and 1,200 A
|Fault Detection Accuracy||3% typical, 20% maximum||20% typical|
|Maximum Voltage||Up to 38 kV (L-L)|
|Latency||Fault detection (SEL-FT50) to Mirrored Bits communications output (SEL-FR12): 6 ms|
|Network Size||12 SEL-FT50 Transmitters per SEL-FR12 Receiver |
16 customer-selectable network IDs
|ISM Frequency Band|
902–928 MHz for United States, Canada, and Colombia
TX power: 30 dBm
902–928 MHz for Mexico
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 Range||4 miles with 20 dB fade margin||4 miles with 20 dB fade margin (2 miles for European Union)|
The Firmware IDs for older versions of the firmware can typically be found in Appendix A of the instruction manual.