Transport Publication TP 127 E
2.1 For the purpose of these Standards, the following cooling air and cooling water temperatures are applicable:
- for ships making foreign and home trade Class I voyages and ships that operate within the tropical belt:
- a primary cooling water supply temperature of 30° C ; and
- a cooling air temperature of 45° C except for electrical machines located in machinery spaces in which case the cooling air temperature is 50° C ; and
- for ships other than those described in paragraph (a):
- a primary cooling water supply temperature of 25° C ; and
- a cooling air temperature of 40° C .
2.2 All electrical apparatus shall be constructed so as to function satisfactorily during voltage fluctuations within 10% below and 6% above the nominal voltage of the system.
2.3 Alternating current apparatus shall be constructed so as to function satisfactorily at frequencies within 5% of the nominal frequency of the system.
2.4 All electrical conductors, switchgear and accessories shall be of such size as to be capable of carrying, without their respective ratings being exceeded, the maximum current that can normally flow through them.
2.5 All electrical equipment shall operate satisfactorily under all conditions with the ship at the following inclination from the normal; transversely: 15° - rolling: up to 22°30' and longitudinally: 7°30' for all ships; emergency installations shall in addition operate satisfactorily when the ship is inclined 22°30' and/or when the trim of the ship is 10°.
2.6 A substantial addition shall not be made to the authorized load of an existing installation until an inspection under Section 36.2 indicates that the current-carrying capacity and the condition of the existing accessories, conductors, switchgear and all other equipment affected are adequate for the increased load.
2.7 Electrical equipment which includes, appliances, accessories and fittings shall bear the classification mark of the Canadian Standards Association ( CSA ); or where special marine type equipment is required and there is no standard for it, it shall be of a type that is safe and effectively fulfils the purpose for which it was intended.
2.8 Notwithstanding subsection 2.7 electrical equipment manufactured outside Canada shall be constructed to meet the most recent version of an applicable rule or code issued by a Society, Association or a recognized Classification Society and shall bear the identification mark of the testing laboratory or certifying authority that verifies that the equipment meets the rule or code.
2.9 Solid insulating materials purporting to be non-combustible and flame-retardant shall conform to the test requirements specified in the C.S.A. Guide for the Preparation of Test Procedures for the Thermal Evaluation of Insulation Systems for Electrical Equipment.
2.10 In general, all electrical equipment shall be constructed of durable, flame-retardant, non-hygroscopic materials which are not subject to deterioration in the atmosphere and temperatures to which they are likely to be exposed; where hygroscopic materials are used in contact with live parts, secondary non-hygroscopic insulation shall be incorporated.
2.11 Insulating materials and insulated windings shall be resistant to moisture, sea air and oil vapours unless special precautions are taken to protect them from their deleterious effects; porcelain, if used, shall not be rigidly fastened by machine screws or the equivalent, and shall not be exposed to direct mechanical damage.
2.12 The distances between live parts of different potential and between live parts and the enclosure or other grounded metal, whether across surfaces or in air shall be adequate for the working voltage having regard to the nature of the insulating material and conditions of service.
2.13 Any grounded metal or parts of the enclosure in proximity to the arc from contactors, circuit breakers or other contacts liable to arc, or in proximity to semi-enclosed fuses, shall be lined with arc-resisting insulating material.
2.14 The design of the electrical equipment shall provide accessibility to all parts requiring inspection and maintenance.
2.15 Apparatus shall be provided with suitable cable or conduit entries; enclosures of drip-proof apparatus shall not have cable entries on the top unless the cable entry plate and cable attachment is so made to exclude water.
2.16 Conductors shall be supported so that no injurious strain is imposed on the terminals of any electrical apparatus or devices or any joints or taps.
2.17 Terminal or connection boxes shall be of sufficient size to accommodate wiring without crowding and each box shall be of adequate mechanical strength and rigidity to protect the contents and to prevent distortion under all normal conditions of service; cables of differing voltage shall not be included in the same junction or terminal box unless each voltage is clearly and permanently identified and effective barriers provided within the enclosure to separate each voltage; terminal connections for incoming cables shall be physically separated from internal connections.
2.18 Machines and apparatus shall be so constructed that their efficiency is not impaired by vibration and shock likely to arise under normal service conditions; screws and nuts securing current carrying parts shall be of a type or provided with a device to prevent them from working loose due to vibration.
2.19 Accessories shall be so designed and constructed that the passages for insulated conductors are of ample size and are free from rough projections, sharp angles and abrupt bends and all outlets for cables shall have well rounded edges or be suitably bushed.
2.20 Accessories shall be so designed and fixed that dust and moisture cannot readily accumulate on the insulation or on live parts.
2.21 Electric radiators shall be constructed to reduce fire risks to a minimum and their heating elements shall not be so exposed that clothing, curtains or other materials can be scorched or set on fire by heat from the element.
2.22 A non-conducting mat or a grating of impregnated wood shall be provided in front of switchgear and control gear assemblies and also at the rear and sides if access is necessary for operation or maintenance. Where assemblies are of the walk-mats or gratings shall also be provided on the inside.
3. Installations, Location, and Protection of Electrical Equipment
3.1 Electrical apparatus shall be so constructed and installed that danger of injury in ordinary handling shall not exist.
3.2 The installation of electrical equipment shall avoid all hazardous locations where explosive dusts, flammable gases or vapors are liable to accumulate unless it is essential for safety or the operational procedures of the vessel. Where electrical equipment is necessary to be located in a hazardous location it shall be of a type certified safe for operation in the particular atmosphere or location as noted in Section 26.
3.3 In hazardous areas where explosion-proof equipment is installed, the integrity of the equipment shall be maintained by the use of suitable explosion-proof rated seals or connectors.
3.4 Switchgear and control and instrumentation equipment shall be mounted in suitable fire resisting enclosures, so located as to be readily accessible for operation and maintenance.
3.5 Electrical equipment shall be so placed that, as far as practicable, it is not exposed to risk of mechanical damage.
3.6 Electrical equipment shall be suitable for the usual general conditions of shipboard marine service and shall be located as far as practicable clear of boilers, steam pipes, fuel tank openings and machinery exhaust pipes or manifolds and shall be protected from dripping water, oil, etc. where necessary when the equipment is inclined at any angle up to 15° from the vertical.
3.7 Electrical equipment used for essential services and located in areas where sprinkler heads or spraying devices for fire prevention are fitted, shall be of an integrity such that water cannot cause malfunction of the equipment.
3.8 Emergency electrical machines and equipment shall not be installed forward of the collision bulkhead.
3.9 Every horizontal rotating machine shall, where practicable, be installed in the fore and aft direction; where a machine has to be installed athwartships, the design of the bearings and the arrangements for lubrication shall be suitable for withstanding the stresses encountered in heavy weather.
3.10 Electrical apparatus shall be so installed that sufficient space is available for maintenance.
3.11 Open type machinery and control gear shall be provided with suitable guards to obviate risk of injury to persons.
3.12 When installing electrical equipment, consideration shall be given to the deleterious effects of galvanic action due to dissimilar metals in contact.
3.13 Switchboards shall be installed so that no pipes or tanks carrying or containing liquids are above them within the same space; where this is unavoidable, pipes shall be without joints in such positions; switchboards which are located immediately above or adjacent to open bilge areas or tank tops shall be enclosed at the bottom.
3.14 Accessories shall be so designed and insulated conductors shall be so installed that stress cannot be applied by the conductors to any terminal to which they may be connected.
3.15 Accessories shall be so designed and fixed that dust and moisture cannot readily accumulate on the insulation or on live parts.
3.16 Where basically different distribution systems are in use, the receptacles and plugs shall be so designed that incorrect connection cannot be made.
3.17 Receptacles shall not be fitted in bathrooms or washrooms unless an a.c. supply is used and the receptacles are each fitted with an isolating transformer; receptacles fitted in bathrooms and washrooms shall be used for electric razors only; on effectively grounded distribution systems ground fault interrupting receptacles may be used in lieu of isolation transformers.
3.18 On weatherdecks, in stokeholds and engine rooms and wherever they are exposed to drip or condensed moisture, receptacles and plugs shall be weatherproof and provided with means for maintaining this quality after removing the plug.
3.19 In galleys, laundries, bathrooms and similar locations, in areas, which are moisture laden, switches shall be of watertight construction or shall be enclosed in insulation which is durable and substantially continuous.
3.20 Electrical radiators shall be fixed in position.
3.21 In special category spaces above and below the bulkhead deck the equipment and installation shall be in accordance with Section 26.21 (a) and (b) respectively:
3.22 Closed Ro-Ro spaces in cargo vessels containing motor vehicles with fuel in their tanks for their own propulsion shall be in accordance with Section 26.22
3.23 The design of devices employed for dimming indicating and instrument lighting located on the navigating bridge shall not permit the total extinguishment of the lamps.