These rules, which enumerate only the essential requirements and precautions for ensuring satisfactory results, including safety from fire and shock, relate to all electrical installations in or on buildings, structures and preises, but shall not apply in premises owned or occupied by any electric supply authority to wiring and apparatus which is used for any purpose other than the consumption of electricity within such premises or for purposes immediately incidental to. They are intended to apply only to installations (or alterations or additions thereto) made or carried out after the date on which This code comes into operation.