(A) Wiring not encased in moulding or approved conduit, shall be supported wholly on non-combustible insulators, constructed so as to prevent the insulating coverings of the wire from coming in contact with other substances then the insulating supports. They shall be so arranged that wires of opposite polarity, with a difference of potential of 250 volts or less, will be kept apart at least 2½ inches, and the above distance shall be increased proportionately where a higher voltage is used. In no event shall the wiring be laid in plaster, cement, or similar finish or fastened with staples.
(B) All wiring not encased in moulding or approved conduit, in unfinished lofts, between floor and ceilings, in partitions, and other concealed places, shall have at least 1 inch clear air space surrounding them, and shall not be less than 2½ inches apart when possible. Wires run as above immediately under roofs, in proximity to water tanks or pipes, will be considered as exposed to moisture. Wires must not be fished for any great distance and only in places where the Superintendent can satisfy himself or herself that the rules have been complied with, and twin wires shall never be employed in this class of concealed work.
(Ord. 24, passed 4-4-1895) Penalty, see § 10.99