Wiring is so fundamental to our society that we often forget it
is a system unto itself. The aging of a wire system can result in
loss of critical functions in equipment powered by the system or
in loss of critical information regarding the operation of certain
parts of the equipment. Either result can jeopardize public health
and safety and lead to catastrophic equipment failure or to smoke
and fire. Consequently, the safety of the nation's wire systems
is an issue of major importance to all of us.
The aging of wire systems was first recognized as an issue of national
concern in commercial aviation. Through efforts underway at various
federal agencies, however, it has become apparent that aging wiring
is an issue that extends far beyond aviation.
With this realization in mind, the Office of Science and Technology
Policy has expanded the focus of wire system safety initiatives
beyond aircraft into other areas, including consumer products, homes
and other buildings, nuclear power plants, public transit, and railroads.
This expansion of focus led to the creation of the "Wire System
Safety Interagency Working Group" (WSSIWG) as a task?oriented
subgroup of the National Science and Technology Council's Committee
on Technology. Chapter 1, "Introduction" describes
the creation of the WSSIWG and the preparation of this report.
The WSSIWG serves as the internal deliberative body of the NSTC
on wire system safety Science and Technology policy, programs, investment
priorities, and direction for the Executive Branch. In support of
its mission, the WSSIWG has prepared this report to document current
federal programs in-and recommend strategies for-improving wire
system safety. The report will also serve as a benchmark for interagency
efforts to optimize government research and will facilitate the
formulation of a national strategy for wire system safety.
Safety issues related to electrical wire systems are discussed
in Chapter 2, "Potential Wire Safety Issues." During
normal service life, all wire systems are subject to aging. If such
aging causes a loss of critical functions or information, it can
jeopardize public health and safety and even lead to catastrophic
failure. Specific issues of concern include damage caused to wire
systems by environmental stresses, improper installation, mishandling
during routine maintenance, and the accumulation of aged wiring
in buildings and other structures.
Chapter 3, "Current Practices" features an agency?by?agency
review of the methods federal agencies are using to manage aging
wire systems for which they have regulatory or operational responsibility.
These current practices flow from-and are limited by-the current
state of wire systems in terms of design, installation, diagnostic
technology and maintenance. In general, they fall into the following
- Conformance with applicable regulations, codes, and standards.
- Training of inspectors and maintenance personnel.
- Inspection, assessment, and maintenance of wire systems.
- Engineering improvements, including modification or modernization.
- Safety investigations.
- Analysis of wire system data.
- Exchange of technical information between agencies.
Studies focused on wire system safety that are currently underway
or planned by federal agencies are summarized in Chapter 4, "Current
Science & Technology Initiatives." The goals of these
initiatives are to identify precursors to failure, predict problems,
preserve integrity and function, and ensure the continued safety
of wire systems.
Chapter 5, "Analysis of Current Practices and S&T Initiatives,"
finds that the federal agencies have the following common issues
and needs regarding aging wire systems. The findings from the analysis
are as follows:
Faulty wire systems pose a risk to public health and safety
and may lead to failure of essential functions and even to smoke
Managing aging wire systems is extremely time-consuming.
Inspection, testing, and maintenance of wire systems is a technical
challenge. In most applications, wire systems are not inspected
or tested-other than by visual inspection-unless an electrical
Most diagnostic procedures currently in use for an electrical
system can detect only "hard failures" that result
in serious deterioration or complete loss of electrical integrity.
Today's diagnostic procedures cannot detect and locate slight
deterioration-such as chafing- before it results in system failure.
Knowledge about how wire systems age and how they fail is limited.
There are limitations to electrical codes and standards. Those
pertaining to fixed structures (buildings) have historically
governed only design and installation and, thus, have tended
to lead to a "fit and forget" approach to wire systems.
Wire systems are becoming more complex with increasing computerization
of operations and of providing information about those operations.
Wire system maintenance is very expensive, and the lack of
access to detailed wiring maintenance data has historically
limited funding to address wire systems issues unless a major
system breakdown occurs.
Current practices flow from-and are limited by-the current
state-of-the-art of wire system technology in terms of design,
installation, diagnosis, and maintenance.
The final chapter of the report is Chapter 6, "Conclusions
and Recommendations." Based on the analysis of current
practices and initiatives, this report concludes that wire system
safety is an important public health and safety issue that transcends
Aging occurs in all parts of all man-made devices and structures.
Wire systems, which are an integral part of virtually all these
devices and structures, are themselves subject to aging. While there
is a tendency to ignore wire systems, there is a pervasive need
to manage aging wire systems so that they continue to function safely.
The government has developed regulations, codes, and standards
and both industry and the government have developed operational
practices that maintain a high degree of safety. However, as they
continue to age and become ever more complex, there needs to be
a higher priority given to wire systems and a more proactive stance
in their management.
Four basic strategies are necessary to improve wire system safety:
- Altering the perception of wire systems.
- Increasing collaboration between industry, academia, and the
- Improving the management and functionality of wire systems.
- Improving wire system technology.
Specific recommendations are proposed to implement each of these
strategies. These recommendations along with the common issues discussed
in this report should serve as catalysts for forging a strong partnership
to revolutionize the way the nation manages its wire systems.
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