ET 101: National Rules for Electrical Installations

These Rules lay down the requirements for the design and erection of electrical installations so as to ensure safety and proper functioning for the use intended.These Rules apply to electrical installations such as those of:

• residential premises

• commercial premises

• public premises

• industrial premises

• agricultural and horticultural premises

• prefabricated buildings

• caravans and caravan sites and similar sites

• construction sites, exhibitions, fairs and other temporary installations (future)

• docks and marinas (future)

These Rules apply to the following:

• circuits supplied at nominal voltages up to and including 1000V a.c. or 1500 V d.c.

• circuits, other than the internal wiring of apparatus, operating at voltages exceeding 1000 V and derived from an installation having a voltage not exceeding 100 V a.c., e.g., discharge lighting, electrostatic precipitators

• any wiring for telecommunication, signalling, control and the like (excluding internal wiring of apparatus)

These rules do not apply to:

• electrical traction equipment

• electrical equipment of automobiles

• electrical equipment on board ships

• electrical equipment in aircraft

• installations in mines and quarries

• radio interference suppression equipment, except in so far as it affects the safety of the installation

• systems for distribution of energy to the public, or power generation and transmission for such systems

• lighting protection of buildings

Note: Atmospheric phenomena are covered, in so far as effects on the electrical installations are concerned (e.g. with respect to selection of lighting arresters).