Distribution systems
39.—(1) In every vessel of 12 metres in length and over to which these Rules apply main and emergency switchboards shall be suitably guarded and so arranged as to provide easy access without danger to any person. Adequate non-conducting mats or gratings shall be provided. Exposed parts which may have a voltage between conductors or to earth exceeding 250 volts direct current or 55 volts alternating current shall not be installed on the face of any switch-board or control panel.
(2) In every such vessel hull return shall not be used for the power, heat and light distribution systems.
(3) In every such vessel where two or more generating sets may be in operation at the same time for providing the auxiliary services essential for the propulsion and safety of the vessel each generator shall be arranged to supply such essential services and means shall be provided to trip automatically sufficient non-essential load when the total current exceeds the connected generator capacity.
(4) In every such vessel cable systems and electrical equipment shall be so installed as to reduce interference with radio reception to a minimum.