General precautions against shock, fire and other hazards.-
(1) In every ship all electrical equipment shall be so constructed and installed that there is no danger of injury to any person handling it in a proper manner.
Exposed metal parts of electrical equipment which are not intended to have a voltage above that of earth but which may have such a voltage under fault conditions shall be earthen unless such equipment is :-
- (a)Supplied at a voltage not exceeding 55 volts direct-current or 55 volts root mean square alternating current to as “RMS a.c.”, from a source other than an auto-transformer, or
- Supplied at a voltage not exceeding 250 volts R.M.S. a.c. by safety isolating transformer supplying only one consuming device or
- Of double insulation construction.
(2) All electrical apparatus shall be constructed and installed in manner that it is not likely to cause injury when handled or touched in the normal manner. When electric lamps, welding equipment, tools or other apparatus are used in confined or damp spaces or spaces with large exposed conductive surface, special provision shall be made, so far as practicable, to ensure that the danger of electric shock is reduced to a minimum. Such spaces shall at least include open decks and machinery spaces.
(3) Every main and emergency switchboard shall be so arranged as to give access as may be necessary for operation and sufficient access for maintenance without danger to any person. Every such switchboard shall be suitably guarded and non-conducting mat or grating shall be provided at the back and front of such switchboard. No exposed parts which may have a voltage between conductors or to earth exceeding 250 volts direct current or 55 volts R.M.S. a.c. shall be installed on the fact of any switchboard or control panel.
(4) The hull return system of distribution shall not be used for any purpose other than the use of :-