Technical information

■ to import into North America: compliance with federal laws, obligation to attest

component conformity and in some cases, to submit the product to authorised

inspectors.

2. Historical evolution of the

North American regulations

The historical reasons that justify the differences described are found not only in

the cultural diversity but also in the communication difficulty between two

worlds, at least up to the end of the XIX century.

The oceanic distances and the different background philosophy have emphasised

the differences up to the recent times; that is why two different approaches to

solve the same safety problem developed at each side of the ocean.

The brief historical account that follows wants to briefly explain how the

structure of the different standards and regulations for electrical system have

developed to be shaped as we know them today.

In the United States Thomas Alva Edison patents the first incandescent light bulb

(1879) and, in 1882 investing the earnings of his patent the best way in the

telegraph,The Edison Electric Light Company is established and a direct-current

power plant is built in New York.Electric current, whether direct or alternating,

propagates really fast and so does the increase of the fires due to electrical causes

and the relevant insurance refunds.

In 1893 during the Universal Exhibition in Chicago,the Palace of Electricity

represents the first time electric energy imposes over any other forms of energy,

and also the time when American insurance companies accept to compromise

only after carrying out thorough inspections of installations.

Under the pressure exerted by insurance companies, and also due to purely

economic reasons in first place, five different installation codes are developed.All

attention is mainly focused on fires that are an unavoidable consequence of

overloads and short-circuits in buildings mainly characterised by the use of wood.

A feature common to all electrical code is the requirement to use safe electrical

components, but the different provisions make it impossible for manufacturers to

produce a common product.

In 1897 the main organisations around the country defined a sole installation

code valid for the whole federation, the National Electrical Code (NEC) which

was immediately adopted by all the main organisations of fire prevention and

protection, and above all, by insurance companies.

At the same time as the NEC, the installation codes for automatic sprinkling

systems were drawn up and the organisation in charge of updating the technical

specifications of both codes (every three years) was set up: the National Fire

Protection Association (NFPA).

INTRODUCTION TO NORTH AMERICAN STANDARDS