Instruction Manual
Table Of Contents
- Major Features and Benefits
- Functional Overview
- System Overview
- Application Examples
- Collect Fault Information From Remote Branches
- Improve Fuse Coordination
- Fuse-Blowing Scheme Shortcomings
- Improve Fuse-Blowing Schemes With the Fault Transmitter and Receiver System
- Fuse-Saving Combined With Fuse-Blowing Schemes
- Improve Feeder Cable First-Span Protection
- Implement a Low-Cost Fast Bus-Tripping Scheme
- Tripping the Right Recloser Faster
- Safety Information
- Network Deployment Overview
- Device Installation
- Dimensions
- Specifications
- Appendix A: Manual Versions
- Appendix B: Two-Branch Application
- Appendix C: Link Budget Analysis
- Appendix D: SEL-RP50 Fault Repeater Detailed Implementation
- Technical Support
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SEL-FT50/SEL-FR12 Fault Transmitter and Receiver System Instruction Manual Date Code 20210405
Appendix D: SEL-RP50 Fault Repeater Detailed Implementation
Appendix D: SEL-RP50 Fault Repeater Detailed
Implementation
The SEL-RP50 Fault repeater provides a method to help break the line-of-sight
restrictions for SEL-FT50 to SEL-FR12 wireless communications paths. This
appendix provides details on where SEL-RP50s can help, and where they might
not. Example system example diagrams explain configuration details.
In situations where obstacles such as trees, terrain, or buildings are blocking line-
of-sight from one or more SEL-FT50s, consider installing one or more
SEL-RP50 Fault Repeaters per SEL-FT50 on the same feeder as the obscured
SEL-FT50s. The repeaters will generally be installed in sets of three. Figure 33
shows a distribution system with two SEL-FT50 Trios, and one SEL-FR12. The
SEL-FT50s nearest the substation have unobstructed line-of-sight back to the
SEL-FR12 antenna. The other SEL-FT50 Trio (lower right part of diagram) is
obscured by terrain, and there is no line-of-sight path. A set of three SEL-RP50s
installed on the same branch in a location with a good line-of-sight to both the
SEL-FT50s and the SEL-FR12 antenna will enable the signals from this
SEL-FT50 trio to get around the obstacle.
Some key points to consider:
➤ SEL-RP50s are not available in all areas. See Table 13.
➤ Each SEL-RP50 only repeats signals from one SEL-FT50, or another
SEL-RP50 with matching Unit ID and Network ID. See Figure 34
and Figure 35.
➤ SEL-FT50s and SEL-RP50s operate using harvested line current,
devices with matching Unit IDs must be installed on the same electri-
cal phase
➤ The SEL-RP50s sharing a Unit ID with an SEL-FT50 must be
installed so fault current passes through all devices.
➤ Each site with three SEL-RP50s can repeat the messages from one
SEL-FT50 Trio, or from another SEL-RP50 Trio.
➤ Up to five sequential SEL-RP50 sites can be installed per SEL-FT50
Trio.
➤ A maximum (but unlikely) configuration would include one
SEL-FR12, twelve SEL-FT50s, and sixty SEL-RP50s.
➤ When the feeder is deenergized the SEL-RP50s are unable to oper-
ate. When a feeder is powered up to a low load condition, the
SEL-RP50 wireless repeaters are in a sleep state and do not continu-
ally operate. In this state they are still able to wake up and repeat
incoming fault messages.
Figure 33 Using SEL-RP50s to get around one obstacle