The SEL Wireless Protection System helps relays make better tripping and reclosing decisions based on the location of a fault, augmenting your existing distribution protection schemes to improve the reliability and safety of your feeder. The system’s components include the SEL-FT50 Fault Transmitter, SEL-RP50 Fault Repeater, and SEL-FR12 Fault Receiver. When the SEL-FT50 detects a fault, it quickly broadcasts the fault status via 900 MHz wireless signals directly to an SEL-FR12 or via multiple SEL-RP50 repeaters to an SEL-FR12. The SEL-FR12 provides the fault status directly to a protective relay or recloser control via high-speed Mirrored Bits communications. In all, it takes just 6 ms to send the data to a protective relay, with each fault repeater used in the communications chain only adding up to 1.5 ms of delay to the overall system latency.
SEL-FT50: $236 USD
SEL-RP50: $236 USD
SEL-FR12: $574 USD
Block Reclosing for Underground Faults—It can be challenging to determine whether a fault has occurred on the overhead or underground section of a feeder. Traditionally, utilities have had to choose between the possibility of undesired reclosing into an underground fault or blocking reclosing for a close-in overhead fault when a high-current lockout is used. By installing the SEL-FT50 at the riser pole, the relay can receive fault status information via the SEL-FR12 before the first trip and know whether the fault is overhead or underground. The relay is then programmed to only allow reclosing when the SEL-FT50 signals that the fault is on the overhead portion of the feeder.
Fast Bus Tripping—Fast bus tripping schemes can provide an economical solution for substation bus protection on radial systems. However, in some cases, communication between relays may not be feasible or may be cost prohibitive. The SEL-FT50 and SEL-FR12 install easily on substation feeders, allowing protective relays to differentiate between a fault on the feeder and a fault on the bus with fast wireless communication to speed up bus protection.
High-Density Recloser Trip Blocking—A higher density of protective devices on distribution networks can help improve reliability metrics by reducing the number of utility customers within any isolation zone. Traditional relaying coordination methods become increasingly difficult to implement as the total number of devices increases. Combining the SEL-FT50, SEL-FR12, and SEL-RP50 can enable relays and recloser controls to implement fast, economical trip blocking schemes while coordinating with lateral fuses.
Think Milliseconds, Not Seconds
The SEL-FR12 can be paired with up to 12 line-powered SEL-FT50 transmitters. Up to 5 SEL-RP50 repeaters can be used to retransmit signals from each SEL-FT50 back to the SEL-FR12. When the SEL-FT50 detects a fault, it quickly broadcasts fault status via 900 MHz wireless signals directly to an SEL-FR12 or via multiple SEL-RP50 repeaters to the SEL-FR12. In all, it takes just 6 ms to send the data to the protective relay, with each fault repeater used in the communications chain only adding up to 1.5 ms of delay to the overall system latency.
Get Around Obstructions With Repeated Signals
The line-powered SEL-RP50 overcomes the communications challenges of obstructions to the radio path’s line of sight by repeating the link and fault status signals from the SEL-FT50. Place one or more fault repeaters between your fault transmitter and fault receiver to reach around corners, go over a hill, bend around branches, and get around other obstacles blocking the line of sight.
Easy to Deploy, Easy to Maintain
The lightweight design of the SEL-FT50 and SEL-RP50 makes them easy to install by simply using a shotgun hot stick to clamp them to the overhead conductor. The SEL-FT50 and SEL-RP50 are rated for voltages up to 38 kV and are completely line-powered, removing the need for battery maintenance.
Reduce Operation and Maintenance Costs
By identifying faults faster and shortening the duration of fault currents, the SEL Wireless Protection System extends the life of equipment, reducing operation and maintenance costs.
The SEL-FT50 and SEL-FR12 are approved for use by governments of the following countries:
The SEL-RP50 is approved for use in the United States and Canada.
The SEL-FT50 Fault Transmitter detects faults and transmits data via an SEL-FR12 Fault Receiver to a protective relay. Communicate the fault status to enhance distribution protection schemes.
For the United States and Canada. To order SEL-FT50 models that are approved for use in other countries, please contact an SEL customer service representative.
The SEL-FR12 Fault Receiver monitors as many as 12 SEL-FT50 Fault Transmitters. It communicates the fault status using high-speed Mirrored Bits communications to a protective relay or recloser control.
For the United States, Canada, and Mexico. To order SEL-FR12 models that are approved for use in other countries, please contact an SEL customer service representative.
The Firmware IDs for older versions of the firmware can typically be found in Appendix A of the instruction manual.