In order to improve the service level and reliability of power supply, utility companies around the world have been investing in medium-voltage construction practices, proving that these goals are achievable. The two antennas used in North America since 1951 are air-isolated cable systems, originally designed by Bill Hendrix; and tree-like wire configurations, which utilize an open structure that covers the wires on the crossed arms with polyethylene insulators. in. This article will present the latest developments in the field of connector technology for use with these covered conductor systems, rather than discussing the features and advantages of both systems.
IPC installed in Europe, using hot rods.
In order to connect the transformer to the covered conductor line, the present invention requires the outer casing to be stripped to mount the connector. In most cases, the faucets are bare and a protective layer is placed over the mess above the faucet to prevent temporary power outages due to tree or animal contact. As an additional standard precaution, lightning arresters have also been used to avoid possible problems during lightning strikes.
Perceived challenges to overlay systems
One of the challenges that utilities face when using spacer cable and overlay systems is that it is difficult to adequately and safely strip the conductors over the conductors before making the taps. When a utility needs to make a tap for a transformer, it is always required to strip the cable. This is a relatively simple process with the right stripping tool. However, tools are not always available or in good working order. In some cases, line workers have begun using knives to strip insulation. This creates a safety hazard on the job site and also the potential for damage to insulation and/or cables, affecting the long-term reliability and integrity of the cable. Other safety issues in the stripping process, such as being too close to the adjacent phase, the awkwardness of the stripping tool, or the temperature rise during the stripping process, essentially cause some utility companies to be reluctant to adopt Cover the wire.
Historically, in transformer connectors, stripped conductors have to be stripped. The faucet is usually bare.
Insulation piercing connector
Advances in technology and the development of insulated perforated connectors (IPCs) have eliminated the need for insulation stripping, which allows the system to be completely insulated and water sealed. This technology has come a long way in achieving the industry's many years of goals, including avoiding stripping altogether, improving line worker safety, avoiding cable damage, and maintaining grid reliability/integrity.
European vs. North American adoption
In fact, IPCs have a long history of use in low voltage systems around the world and have been used in medium voltage (MV) applications in Europe for more than a decade. The application of IPC technology in the United States has been slow, but this situation is about to change as the new IPC makes significant progress in addressing industry concerns.
European standards for covered conductance are quite different from those of the United States, which have been incorporated into international standards. The standard used in North America has a much higher insulation requirement for overhead cables than in Europe. Although IPCs passed the EU standard type test many years ago, there is concern about the use of IPCs on thicker insulation. Overcoming this problem with IPCs in ANSI C119.4.3
In order to solve the challenges faced by IPCs, a rigorous and comprehensive type test procedure (see Table 1) was designed, focusing on all concerns of ANSI C119.4, as well as type testing of EN-50397-2 (when ANSI standard) Did not address a specific concern contained in the European Standard).
Industry concerns and early adopters
Utilities across North America are still skeptical about improper installation of IPCs and possible system failures (just like they are for any "new" technology). Further research has shown that in the absence of IPCs, failure due to improper stripping and tapping is an unfortunate industry reality. Installation of IPCs is by no means inconsequential and should follow the official installation process. But the industry's goal is to reduce failures and accidents to zero, and IPC supporters in the coverage conductor market hope that the new IPC technology will help in this regard.
Early adopters of IPC technology believe that the widespread introduction and adoption of IPC technology is the logical next step in improving grid reliability. The use of covered conductors, such as the Hendricks overhead cable, as part of the mesh hardening is a start. With proper mounting techniques, the implementation of the cover conductor can be a huge success. And the use of IPCs simplif