All electrical wiring shall conform to the National Electrical Code, current edition, except as specified below:
(a) Festoon wiring shall be allowed where not accessible to the public and when not less than eight feet high when indoors and when not less than 10 feet high when outdoors; provided, that where vehicles or structures are or may come under such wiring, the wiring shall be five feet higher than the highest part of such vehicle or structure, including counters; provided further, that no combustible drapes, paper or other decoration is allowed within two feet of such festoon wiring; provided further, that there are no electrical conductors, terminals or contacts that are not properly insulated for 300 volts; and provided further, that such festoon wiring is for temporary use not to exceed 30 days.
(b) All wiring installed permanently in buildings owned by the city shall be installed in compliance with the National Electrical Code and in rigid metal conduit or in metal wireways or busways of equal strength and rigidity of each respective installation.
(c) All wiring installed in buildings owned by the city for temporary use not to exceed 30 days shall be installed in compliance with the National Electrical Code and shall be armoured cable, nonmetallic sheathed cable, electrical metallic tubing, rigid metal conduit or equivalent metal wireway or busway and shall be installed with proper fittings, outlets and devices for such use.
(d) Extension or flexible cords shall not be used if in a worn or otherwise unsafe condition and when used shall be on the Type S hard service cord as listed in Table 19 of the National Electrical Code and shall not exceed 25 feet in length except that portable fixtures and devices bearing the label of approval of Underwriters’ Laboratories, Inc., may be used with cords not to exceed six feet in length when cord is the cord regularly supplied with such device, and when used in places that are dry and not hazardous and when not subject to hard wear. (Code 1941, Art. 96-7)