It is unlawful for any person to fail or refuse to give the personnel of the municipal utility department free access, at reasonable hours of the day or in case of emergency at other times, to all parts of buildings and premises served by the water system, the gas system, the electric system or any other city owned utility or enterprise, for the purpose of performing their official duties in connection with such utilities and enterprises. Such personnel shall have such right of access; provided always, that such personnel are properly identified. (1988 Code § 17-102)