Standards ensure that products are suitable for use on the purpose they are intended. Users are now increasing awareness of the value of purchasing a product certified to national and international standards that ensures the quality of manufacture, and that the product does not have design faults which are likely to make it fail prematurely in normal service leading to financial saving not only of the cost of early replacement but also of the cost of 'down-time'.
A standard is defined as a technical specification or other document available to the public, drawn up with the cooperation and consensus or general approval of all interests affected by it, based on the consolidated results of science, technology and experience, aimed at the promotion of optimum community benefits and approved by a body recognised on the national, regional, or international level.
Most countries have national standards body whose main function is the preparation and/or publication of national standards and/or the approval of standards produced by other bodies.
The international standards organisation primarily concerned with electrical standards is the International Electrotechnical Commission (IEC).
The primary objectives of a standard are
- To provide a set of criteria by which a product can be verified to be suitable for the purpose for which it is intended in comparison with similar products from other manufacturers or sources. This value provides advantage to both manufacturer and the customer.
- To avoid the pitfalls of proliferation of sizes and performance specifications. In the absence of standardisation, it would be difficult to replace a damaged component by one of different manufacturer or even from the same manufacturer if modifications have been subsequently made to the design.
- To ensure compliance to safety requirements and design criteria to warrant that it is safe in normal use.
The certification to safety standards gives also a degree of protection against legal action in the event of accident involving the product.
The value to the general public at large, of standardisation is the improved reliability of the equipment around them, giving longer uninterrupted service and greater personal safety.
Safety aspects contained within product specifications establish matters such as marking of the product to inform the user of the product ratings and limitations, and where necessary to warn of dangers of misapplication.
Safety tests are also included in standards. In some cases, the level of safety is indicated in the title of the standard e.g. if it states that it is intended for use by authorised persons, which implies that there can be an additional level of hazard if used by unqualified person.
A quality assurance procedure provides a standard framework for regular checking to ensure maintenance of quality in production, and continued adherence of the product to the standard to which it is claimed to conform.
Manufacturers of products for export are required to conform with the appropriate standard which applies to the particular country to which they are exporting. The may already have test certificates to certify complete compliance with their local standard, the other country may have national standards which differ significantly. Some countries have local regulations and trade practices which enforce series of re-testing by local test bodies in their own country to ensure compliance to local standards.
Electrical Standards and bodies
Philippines Electrical Code (PEC) published by the Institute of Integrated Electrical Engineers (IIEE).
The National Electrical Code, produced by the National Fire Protection Association (NFPA); and The National Electrical Safety Code, produced under the auspices of the Institute of Electrical and ElectronicEngineers (IEEE).
The British Standards Institution (BSI) is the recognised body for the preparation and promulgation of national standards in all fields.
European Committee for Electrotechnical Standardisation (CENELEC). The standardisation institutions of Western Europe formed the European Committee for Standardisation (CEN) which coordinated the drafting of standards within the two regional trading groups: The European Economic Community (EEC) and the European Free Trade Area (EFTA).
- International Electrotechnical Commission (IEC)
The International Electrotechnical Commission (IEC), was established in 1906, and now comprises the national electrotechnical committees ofover 60 countries in all continents throughout the world.
IEC Standards are widely adopted as the basis of national electrotechnical standards so far as local customs and conditions permit. They are also quoted in manufacturers' specifications and by users when calling for tenders.
This widespread adoption facilitates international trade in the electrical and electronic engineering sectors.
- Underwriters Laboratories Inc. (UL)
The Underwriters Laboratories Inc. (UL) is an independent non-profit organisation in the USA which was originally set up by the insurance underwriters to carry out testing for public safety. A complete description of the organisation, purposes, and methods of UL can be found in a pamphlet 'Testing for Public Safety' obtainable from UL.
- International Organisation for Standardisation (ISO)
was founded in 1947 in the aftermath of World War II, and the national standards bodies of approximately 90 different countries now participate in its work.
ISO produces standards which are published on approval by 75% of the member bodies. ISO is governed by the ISO Council, and within the organisation there are in excess of 2000 technical committees, sub committees, and working groups involved in the preparation of International Standards. ISO had published approximately 8000 standards in the 20th century. In principle, ISO does not produce electrical standards, this being the province of its electrical counterpart the IEC.
A Regulation is a binding document which contains legislative, regulatory or administrative rules and which is adopted and published by an authority legally vested with the necessary power. References made to standards in regulations may have one of two effects:
- Standards made mandatory: the standard or the part of the standard which is referred to must be followed, or a specific result in a standard test must be achieved in order to obey the statutory requirement. This means that the text in the standard ceases to be voluntary in the context of the legal requirement.
- Standards deemed to satisfy: in this case, compliance with the standard is indicated as one way of fulfilling a regulatory requirement. It is possible to choose another route to fulfil the requirement, but those doing so may be required to prove that their alternative complies with the regulation.
Structure of a typical standard
The following is the structure of a typical IEC standard specification:
- Foreword (followed by preface and introduction where appropriate), giving the background to the specification and its international development;
- Conditions For Operation in Service;
- Standard Conditions for Construction; and
This structure has been criticised in the past in that it sometimes leads to a certain degree of repetition in different clauses. However this disadvantage is offset by the considerable advantage that all the requirements are clearly stated in each clause, and all the test requirements are gathered together in the final section rather than being distributed throughout the text. It is thus perfectly clear exactly what has actually been tested and what the product has achieved if it successfully complies with the specification.
Testing, certification and approval
To confirm compliance of products with standards, it is necessary to test and to mark the appropriate products to identify compliance with the appropriate standard and/or that the manufacture is maintained at an acceptable level of quality.
The local certification and assessment body is responsible not only for the certification of products but also for the assessment of the capabilities of manufacturers and the service industries. The growing realisation Of the importance of quality and reliability in goods and services has caused rapid growth in the percentage of firms seeking registration.
Registration and maintenance to such a quality standard has a dual advantage. Compliance is not only an attraction to customers, it is also a benefit to the efficient business of the registered firm improving its competitiveness and ensuring the maintenance of that quality by independent assessment to standards.
Electrical Engineers Reference Book
M. A. Laughton