Electrical codes arose in the 1880s with the early commercial introduction of electrical power. Many conflicting standards existed for the selection of wire sizes and other design rules for electrical installations. The intention of wiring safety codes is to provide safeguarding of persons and property from hazards arising from the use of Regulations may be set by local city, provincial/state or national legislation, perhaps by amendments to a model code produced by a technical standards-setting organization, or by a national standard electrical code.
The first electrical codes in the United States originated in New York in 1881 to regulate installations of electric lighting. Since 1897 the U.S. National Fire Protection Association, a private nonprofit association formed by insurance companies, publishes the National Electrical Code (NEC). States, counties or cities often include the NEC in their local building codes by reference along with local differences. The NEC is modified each three years. It is a consensus code considering suggestions from interested parties. The proposals are studied by Committees of engineers, tradesmen, manufacturer representatives, fire fighters, and other invitees.
Learn more about Knob & Tube Wiring – Electrical Wiring in Buildings here >>