The following are hereby adopted as safe and practical standards for the installation, alteration and use of electrical equipment in the city:
A. The rules and regulations of the National Board of Fire Underwriters, as contained in the code known as the national electrical code, and as approved by the American Standards Association, as last published.
B. The rules and regulations regarding the installation, alteration and use of electrical equipment as adopted by the electricity supply company now supplying the city, as last published and filed with the Illinois commerce commission, a copy of said code and the last mentioned rules and regulations being now on file in the office of the clerk and of the electrical inspector. (1967 Code § 17.002)