Abstract
There has been an increasing emphasis in recent decades to
achieve international codes and standards for electrical
installations and products. Although the bene-fits of unified
documents and products worldwide seem obvious, the migration
to such internationalization requires management that
considers regional differences of elements such as: the
presently installed base, practices used in construction,
infrastructure and expectations of users.
The North American electrical safety system
has been developed carefully, is operating safely, and is
largely homogeneous. Because it is uniform, a single set of
product standards for the region is presently realizable.
There are elements of this system that should be preserved and
perhaps captured in the worldwide system toward which we may
be heading. This article examines the hand-in-hand functioning
of installation codes and product standards and their
enforcement in North America as strengths to be recognized and
preserved. These elements and their linkages are a foundation
of the safety system to build upon.
Introduction
In the rush toward global harmonization of codes and
standards, it is worthwhile or perhaps necessary to understand
the cornerstones of safety in the present system. Examining
the "life" of an electrical installation, one
realizes that a typical installation usually lasts well over
25 years, in many cases. Through its life, the system will be
interconnected with similar electrical systems and various
types of equipment. Any upgrades and expansions of the system
must also be compatible over its life. Although the electrical
system may not change rapidly, it must retain safety. This
article examines some of the elements of the electrical safety
system and recognizes that they are already regionally in
place across North America, and suggests that regional
harmonization be strengthened on the way toward examining
feasibility of worldwide harmonization.
The Homogeneous
North American Electrical System
Throughout North America, one finds a 60 Hz system with common
voltages and a single, basic practice for grounding of
low-voltage, utilization level systems.1, 2 Similar systems are found in many countries in South and
Central America and in other regions of the world in which
North American style equipment predominates or in which North
American companies operate. Contrast this picture with that of
Europe in which frequency is 50 Hz and a variety of electrical
systems is used, but almost never the American style
electrical system. Residence and office distribution voltage
is 230 V rather than the 120 V used throughout North America.
It should be understood that construction practices, training
provided to installation professionals and expectations of
users differ from those of North America.
Code Impact
Recognize that the governing installation code largely
influences requirements of product standards. Installation
codes used in Canada, USA and Mexico are largely similar, and
product standards in the region are carefully tied to the
codes. By contrast, International Electrotechnical Commission
(IEC) product standards generally support installation codes
employed in European countries and do not necessarily have any
relation to those of North America. Electricity production in
North America is over 4.5 trillion kWh annually while that of
the European Union is less than three trillion kWh.3
The North American
Electrical Safety System
If we step above the physical system to the infrastructure
that provides for the safety of installations, we again find
common elements throughout NA. Namely, we find linkages among
the installation codes, the product standards and the
inspection and enforcement system (see figure
1). The linkages provide for safe products and safe
installations.
The Installation Codes as Safety Drivers
We have already mentioned that the three installation
codes, the National Electrical Code (NEC),4 the Canadian Electrical Code (CEC),5 and the Mexican Electrical Code, NOM-001 (MEC),6 are largely similar. The codes serve as the drivers for safety
by directing the safe installation of products and the system.
The NEC states in 90.1, "The purpose of this code
is the practical safeguarding of persons and property from
hazards arising from the use of electricity." Similarly,
the CEC states in Section 0, "Compliance ... will ensure
an essentially safe installation." Safety is the focus.
The codes enumerate the requirements for
safe systems while helping to ensure the use of safe products.
Safe products fit within an integrated system, are rated for
their application and meet minimum safety requirements. Code
requirements influence requirements of product standards. For
example, the product standards establish permitted temperature
rises in equipment based on a properly selected conductor
being used. The code establishes the selection rules for the
conductor on specific applications. Without proper
coordination, an improperly selected conductor could lead to
equipment operating at temperatures above the permitted
limits. This is one of thousands of requirements under which
the codes and product standards are linked.
Product Standards Set Minimum Requirements
for Safety
In the foreword and introductory sections of North
American product standards (e.g., UL Standards) is a statement
noting that the requirements in the standard are for safety.
When it comes to evaluating product compliance in Mexico,
Canada, the USA, or elsewhere the requirements in the
standards are safety requirements.
Product standards in general establish
minimum safety requirements for performance, construction,
marking and certification. Performance and construction
requirements do not necessarily relate to the function the
product will provide to its user. Rather, these requirements
relate to extreme or abnormal conditions products may
encounter in service and avoidance of shock or fire hazard
under such conditions.
Further, products must be used together in
a system. The installation codes provide guidelines, if not
requirements, for safe compatibility of products. For example,
in temperature testing a piece of equipment, the temperature
at wiring terminals cannot exceed the temperature rating of
the insulation of the conductors that will connect to them. As
another example, current and voltage ratings and operating
performance of wiring devices and other equipment used in
electrical systems correspond to ratings of overcurrent
protective devices. When a 20 A circuit is installed in
accordance with the code, all devices certified to linked
standards and rated for use in or attached to a 20 A circuit
are compatible, from overcurrent protection to wiring to
receptacle outlets and beyond. Whether the linkage is
pronounced or submerged, there is an important linkage between
the installation code and individual product standards.
When products are labeled as having been
certified or listed to appropriate standards, additional
evaluation by inspection authorities at the installation site
is not necessary. Certification to the standard driven by the
code means that the product has been determined to satisfy
specified safety requirements and can be installed in
compliance with the code requirements. Section 90.7 of the NEC states, "For specific items of equipment and materials
referred to in this Code, examinations for safety made
under standard conditions will provide a basis for approval
where the record is made generally available through
promulgation by organizations properly equipped and qualified
for experimental testing, inspections of the run of goods at
factories, and service-value determination through field
inspections." A similar statement appears in 2-024 of the
CEC. Recognize that the link between the installation code and
product standards exists within the North American electrical
safety system and is essential for safe products in safe
installations.
Enforcement by Inspection
Throughout NA there are electrical inspectors who are
usually an arm of a state, municipal, county or provincial
government. The inspector verifies that the installation
complies with the code. This is a check on the system by
people trained in the code who are removed from the design,
construction or operation of the site. In addition, a solid
inspection system provides for uniform interpretation of the
code throughout the area. Because the inspector must interpret
the code relative to a variety of fully-installed systems, he
or she helps provide useful feedback to improve the safety and
usability of the other parts of the safety system.
Inspection and enforcement ties to the
other parts of the infrastructure in that it uses the code as
the basis for inspection and provides the legal enforcement
mechanism for the requirements. Labeled evidence of compliance
with the standard provides the inspector with a means of
knowing that products are suitable for application under the
code requirements.
Under this system of inspection, products
that have not been determined to comply with standards are
unlikely to be used. In addition, products that are applied
improperly are often identified and not accepted as installed.
Of course, methods exist to provide for compliance of special
products or products for which no standard exists. This can be
accomplished by examination by the inspector if he or she has
the proper expertise or examination by a certification
organization such as Underwriters Laboratories (UL),
Asociacion Nacional de Normalizacion y Certificacion del
Sector Electrico (ANCE), Canadian Standards Association (CSA)
or other similar organizations.
The International Association of Electrical
Inspectors (IAEI) represents many of the inspectors in all
three North American countries. One of its objective is:
"To cooperate in the formulation of standards for the
safe installation and use of electrical materials, devices and
appliances and to promote the uniform understanding and
application of the National Electrical Code and other
electrical codes." 7
The Three Legs
The North American electrical safety system consists of
the three interdependent parts described; codes, standards and
inspection. Together they can be thought of as a three-legged
stool. Each leg must be present for the system to competently
support safety. No leg can adequately stand alone without its
tie to the others. It is a proven system built by experience
and the hard work of many.
There are a number of apparent forces that
may be acting to change or replace this highly effective
system. Acknowledging that continuous evolution is desirable
and is provided for in the existing system, any great and
rapid change could severely challenge the safety of North
American electrical installations.
International
Electrotechnical Commission
One possible challenge to the system is replacement of
existing product standards or even the installation codes with
standards of the International Electrotechnical Commission (IEC).
Under the somewhat misleading assumption that IEC Standards
are worldwide standards, such a step would certainly be
perceived as a move toward unification of world electrical
systems. It would, in theory, allow the interchange of
products made to a single set of minimum safety standards
throughout the world. This kind of unity sounds good in
international trade discussions, but moving blindly would be
unwise in regards to electrical safety.
IEC is a standards development organization
(SDO) that prepares and publishes standards for electrical,
electronic and related technologies. It also operates
worldwide schemes for assessing conformity to those standards.
Participation is through the national committee of each
participating nation.8 Presently there are 63 participating nations. Within its
structure there are 172 Technical and Subcommittees and
roughly 900 Working Groups, Project Teams and Maintenance
Teams. The USA, Canada and Mexico are all participating
members.
Since North American countries participate,
at least to some degree, in the development of a number of the
IEC standards, why should not these IEC standards become the
adopted standard in North America? Here are several points to
consider.
1. None of the IEC standards are linked
to the North American codes. If they are linked to any code,
they are linked to the IEC 60364 series of documents. There
is no way to tell whether a product that satisfies an IEC
standard is compatible for use with other products in a
system installed in compliance with a North American code.
2. IEC standards are not generally
reflective of regional practices, products and
infrastructure employed in North America. One of the
greatest influences in the development of IEC standards has
been CENELEC.9 CENELEC is a well-organized SDO with membership of 28
participating European countries plus 8 affiliate countries
from Central and Eastern Europe. CENELEC standards define
the conditions for access of electrotechnical goods and
services into the European Market. Of the 63 countries
participating in IEC, 33 of them are associated with CENELEC.
In the one-country one-vote system of IEC, North America has
a maximum of three votes.
3. Though many nations throughout the
world contributed to the development of these IEC standards
including the USA and Canada, the greatest input to these
standards was European. European countries have largely
adopted the standards in some form and employ them under
their national installation codes.
4. The term international standard does not mean safe for application everywhere.
Four Issues
Four issues have arisen from the standards harmonization and
safety perspective.
1. International standard means
IEC standard.
2. IEC standards are "better"
than North American counterparts.
3. IEC standards can always be adopted or
adapted with only minor country deviations.
4. Manufacturers’ reputations and
suppliers’ declarations are preferred conformity
assessment procedures.
International Standard means IEC standard
Trade agreements such as the North American Free Trade
Agreement (NAFTA) and the WTO do use the term international
standard in their text. The immediate assumption by many
is that the term international standard refers to IEC
or ISO standards. Although some definitions for international
standards may reference IEC and ISO standards as examples, the
definitions do not limit the term to standards developed by
these organizations.
In comments to the World Trade Organization
Committee on Technical Barriers to Trade, the following
written comment was made: "The United States continues to
believe that bodies which operate with open and transparent
procedures which afford an opportunity for consensus among all
interested parties will result in standards which are relevant
on a global basis and prevent unnecessary barriers to
trade." 10
Internationally accepted standards which
provide for this open and non-discriminatory access should be
considered international standards. A good example would be
the National Electrical Code developed under the
National Fire Protection Association (NFPA) consensus process.
IEC standards are "better" than
North American counterparts
IEC and North American standards are all good standards,
competently developed and proven by field experience.
Components of each system work well when used in the system of
infrastructure for which they are intended. One is not better
than the other. They are different, based on different
practices.
The real issue is the mixing of products
designed to standards that are not linked. The differences
could result in incompatibilities that affect the safety of
the electrical system.
IEC standards can always be adopted or
adapted with only minor country deviations.
It has been questioned whether North American standards
can be replaced by adopting IEC standards or adapting them via
minor in-country "deviations" to account for
specific code practices. In some cases, near compatibility
exists to start with and adaptation or adoption makes good
sense. However, in one case in which "deviations"
were listed, the list occupied as many pages as the applicable
North American standard. A simple review of the existing
installation code does not identify the necessary deviations.
Some linked requirements are not obvious, though they are the
result of years of co-development of the code and product
standard.
Manufacturers’ reputations and suppliers’
declarations are preferred conformity assessment procedures.
Manufacturers’ declarations of conformity to electrical
equipment standards are not generally acceptable to users,
manufacturers or inspectors in North America. In general, all
prefer third party certification for assurance, uniform
interpretation and liability purposes. As mentioned above,
electrical codes permit installation of equipment that has
been approved by the authority having jurisdiction. To grant
approval, those authorities typically rely on listing and
labeling by an organization equipped and recognized for that
purpose. In defining the term listed, the codes in the
USA and Mexico specifically discuss periodic inspection of
runs of goods at the factory as a follow-up to the initial
evaluation and testing program. In Canada, follow-up
inspection is also required though not specifically mentioned
in the code. Follow-up inspection at the factory is an
essential and highly valuable service that provides for
conformance through the manufacturing life of a product.
Preserving The
System
Several basic and key steps can be taken to preserve and
further unify the North American electrical safety system.
1. More clearly cross-reference codes to
product standards for safety.
2. Harmonize product standards within North
America.
3. Globalize the inspection and
enforcement concepts.
There may be useful work in tying product
standards to codes. Presently, code requirements are written
with no referential or process link to product standards.
People who work with codes and standards have informally taken
responsibility for updating product standards as codes are
revised. Code process participants continually cite the fact
that a product standard requires certain tests and
construction to justify acceptance of a code rule. Conversely
to that it has been stated that if the code does not state a
specific product standard, then anything can be used. This
thinking can result in detrimental effects to the safety
system. To address some of this concern, the NEC was
modified to add Annex A that provides an informative list of
product standards that are applicable to products that are
required to be listed by the Code.
Regarding point 2, there is presently a
North American initiative to harmonize product standards for
many products throughout the three countries. Harmonization is
carried out under the Consejo de Armonizacion de Normalizacion
Electrotecnica de las Naciones de America (CANENA) or the
Council for Harmonization of Electrotechnical Standardization
of the Nations of the Americas. CANENA is an umbrella
organization that assembles harmonization committees, composed
of members from participating countries, to work together. The
standards developed are adopted by the SDO for each country,
such as ANCE in Mexico, UL in the USA and CSA in Canada. The
result of the process is a single standard published by the
participating SDOs and containing the requirements for all
participating countries. To a great extent, the standards
permit a single product to be applied in any of the
participating countries. These standards may also be
harmonized with counterpart IEC standards to the extent
possible based on infrastructure considerations and the
installation codes.
The emergence of harmonized standards
throughout North America or throughout the Americas recognizes
the similarity of electrical systems and/or of electrical
safety systems. It supports the link between product
standards, installation codes and the inspection authority
throughout the region. It will also provide for a more closely
unified view as the next steps in harmonization with or
adoption of IEC standards are taken. This is in addition to
the benefit of having a single product suitable throughout the
region.
On point 3, electrical inspection is a
vital public safety function. It helps protect the system from
corruption, intentional or unintentional. It provides for
uniformity of installations to a recognized safety code.
Strengthening of this leg of the electrical safety system
should be encouraged worldwide. The International Association
of Electrical Inspectors has sections and chapters throughout
North America as well as some limited areas in other
geographic regions. They provide important activities in
training and coordination of the inspection community
regarding interpretation of codes and inspection practices.
Opportunities for the Americas
The homogeneity of electrical systems is not solely true for
North America. Other nations of the Americas and elsewhere
share similar electrical systems and interests for a common
safety system. A version of the NEC has been used in
Colombia, Venezuela, Panama, Saudi Arabia, Puerto Rico and the
Philippines. All of these nations would share an interest in
product standards that are linked to their national code and
could be supportive in making that link by having practices
from those codes and standards recognized in either IEC
standards or in regional standards.
North American Influence
Customer focus
Customer needs, consistent with safety practices must drive
any approach to codes and standards. This statement leads to
the thought that systems are best when open to the application
of whatever product fits the customer need, a product
appropriately certified to whatever standard that properly
supports the installation code.
Two systems
It should be recognized that there are two approaches to
electrical safety systems in the world today. There is the
North American system with its set of practices linked to very
similar installation codes. There is also the European safety
system with IEC standards at the center. Both are very good,
but they are different. Pressuring either one to throw out
existing standards in favor of the standards of the other
would be unwise, unsafe and impractical.
One system
One worldwide system can only be achieved when standards
become truly international. If the international standards are
to be IEC standards, they must recognize North American
principles and practices. Harmonization means an understanding
of differences between installation codes and effective steps
to account for them with safe product requirements.
Conclusions
1. The North American electrical safety
system is comprised of linked installation codes, product
standards and the inspection function. These are the three
legs of the system. None of these elements is a standalone
element to be replaced without recognizing the other two.
2. The North American system is the
largest in the world in terms of electricity consumption. It
is largely homogeneous today in terms of the three legs of
the electrical safety system and also in terms of the
electrical systems installed. This regional unity should be
recognized.
3. International standards are not
limited to those developed by IEC and ISO. Because of the
unique nature of North American electrical systems and the
links of the safety elements, unified application of present
North American standards is a safe approach that retains the
integrity of the infrastructure.
4. Most IEC standards were not developed
in consideration of North American installation codes. As
such, key linkages for safety between the codes and the IEC
standards do not exist and adoption or adaptation of IEC
standards must be approached with caution.
5. Identical or equivalent harmonized
standards are being developed and published within the three
North American countries. These standards contain
requirements linked to the codes for safety. They often
permit a single product to be used in all three countries,
with minor modifications in some cases.
6. The needs of customers, consistent
with safety practices, must be a primary consideration in
any action.
7. There are presently two approaches to
electrical safety systems in the world: the North American
system and the European (IEC) system. As we discuss moving
toward a single, worldwide system, the infrastructures of
both systems as well as of other smaller systems which may
have unique needs must be accommodated.
References
1 ANSI/IEEE Std. 142-1991, IEEE Recommended Practice for
Grounding of Industrial and Commercial Power Systems.
2 ANSI/IEEE Std. 242, IEEE Recommended Practice for Protection
and Coordination of Industrial and Commercial Power Systems.
3 2005 World Fact Book, U.S. Central Intelligence Agency.
4 ANSI/NFPA 70-1996, National Electrical Code.
5 CSA Standard C22.1-98, Canadian Electrical Code, Part 1.
6 NOM-001-SEMP-1994, Norma Oficial Mexicana.
7 IAEI.org
8 International Electrotechnical Commission – web site, 2005
9 "CENELEC, Its objectives, structure and activities,"
printed 3/6/98 from the CENELEC web site, Brussels.
10 US Contribution to WTO Committee on Technical Barriers to
Trade - G/TBT/W/64 - April 2, 1998.
Based on "North American
Codes and Standards: A Global Challenge," by James T.
Pauley, P.E., Member, IEEE, Square D Company and George D.
Gregory, P.E., Senior Member, IEEE, Square D Company, which
appeared as an IEEE White Paper. Copyright, 1998, IEEE.
Jim Pauley is Vice President,
Industry and Government Relations for Square D
Company/Schneider Electric North America. He is a member
of NEC CMP 2, the NEC TCC and the NFPA Standards
Council. In addition he is the US Technical Advisor to
IEC TC 64 - Electrical Installations in Buildings and
Chairman of the ANSI Executive Standards
Council.Technical Advisor to IEC TC 64 - Electrical
Installations in Buildings and Chairman of the ANSI
Executive Standards Council. |
