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 :-
- Impressed current cathodic protection system.
- Limited and locally earth systems, and
- Insulated monitoring devices with a maximum circulation current of 30 mill-amperes.
(5) Earthen distribution systems shall not be installed in any tanker, chemical tanker or gas carrier.
Provided that the natural of an alternating current distribution system with a line voltage of 3000 volts and above may be earthed if any current their from does not flow directly through and hazardous areas.
(6) The insulation of any distribution system which is not earthed shall be continuously monitored by a system capable of giving audible and visual indication of low insulation values..
(7) Every separate electrical circuit shall be protected against short circuit.
(8) Each separate electrical circuit other than a circuit which operates the ships steering gear or any other circuit in respect of which the Director General of Shipping grants an exemption, shall be protected against overload. There shall be clearly and permanently indicated on or near each overload protective device that current carrying capacity of the circuit which it protects and the rating of setting of the device.
(9) All lighting and power circuits terminating in a bunker or cargo space shall be provided with multiple pole switches outside the space for disconnecting all such circuits.
(10) Accumulator batteries shall be housed in boxes or compartments constructed to protect the batteries from damage and ventilated to minimize the accumulation of explosive gas.
(11) Electrical or other equipment which may constitute a source of ignition of flammable vapours shall not be installed in any compartment assigned to accumulator batteries.
(12) Accumulator batteries shall not be installed in sleeping rooms.