Cart (0)
- No items in cart.
Total
$0
There is a technical issue about last added item. You can click "Report to us" button to let us know and we resolve the issue and return back to you or you can continue without last item via click to continue button.
Not a subscriber? Register for a trial account.
Already a subscriber? 
MADCAD.com Free Trial
Sign up for a 3 day free trial to explore the MADCAD.com interface, PLUS access the
2009 International Building Code to see how it all works.
If you like to setup a quick demo, let us know at support@madcad.com
or +1 800.798.9296 and we will be happy to schedule a webinar for you.
| Email * | |
| Password * | |
| Confirm * | |
| First Name * | |
| Last Name * | |
| Title | |
| Company Name * | |
| Company Size * | |
| Industry * | |
| Address * | |
| Address 2 | |
| City * | |
| State * |
Zip *
|
| Country * | |
| Phone * | |
| How did you hear about MADCAD.com? * |
|
Reset password
Enter your personal account email address to request
a password reset:
a password reset:
Reset password
Enter your account email address to request
a password reset:
a password reset:
Security check
Please login to your authorized staff account to use this feature.
Are you sure you want to empty the cart?
Report To Us
Contact us for a custom quote
⨯To continue with accurate pricing,
please select your company type below:
⨯We need your input!
Are you a code official in a jurisdiction with less than 300,000 population?
⨯ We need your input!
Download File
eLibrary >
24/30477334 DC BS 8450 Installation of electrical and electronic equipment in ships. Code of practice >
Expand All
TOC Search:
24/30477334 DC BS 8450 Installation of electrical and electronic equipment in ships. Code of practice, 2024
- 30477334_Form 36
- 30477334_pdf [Go to Page]
- 1 Scope
- 2 Normative references
- 3 Terms and definitions [Go to Page]
- 3.1 appropriate authority
- 3.2 computer-based system
- 3.3 DP (dynamic position) control system
- 3.4 hazardous area
- 3.5 high voltage
- 3.6 low voltage
- 3.7 non-hazardous area
- 3.8 valve-regulated battery
- 4 General recommendations [Go to Page]
- 4.1 Voltage and frequency [Go to Page]
- 4.1.1 In circuits supplied by batteries (given that the voltage variations in BS IEC 60092-101 are likely to be exceeded, particularly where the battery is normally on floating service) the apparatus supplied should function satisfactorily within the ...
- 4.1.2 Batteries supplying the emergency services should be capable of carrying the emergency electrical load without recharging, whilst maintaining the voltage of the battery throughout the discharge period within 12% above or below the rated voltage.
- 4.1.3 The supply system should be designed such that if the defined transient limits are exceeded this does not cause maloperation or damage to other equipment.
- 4.2 Design of equipment [Go to Page]
- 4.2.1 All apparatus should be of a design appropriate to the situation in which it is likely to be used and its mode of installation should take account of the conditions likely to be encountered in service.
- 4.2.2 The design of equipment should provide accessibility to all parts requiring inspection or replacement in service.
- 4.2.3 Electrical and electronic equipment that operates under automatic or remote control should do so such that the risk of damage to plant or injury to personnel is judged to be as low as reasonably practicable.
- 4.2.4 Equipment should be designed, constructed and installed in accordance with BS IEC 60533 and BS EN 60945, as appropriate, with respect to the electromagnetic compatibility (EMC) of the electrical equipment and systems of the installation.
- 4.2.5 Materials used for items associated with systems which are required to operate as long as possible in a fire (e.g. cables for certain alarms and shutdown systems, navigation lights, communication systems, emergency lighting) should be selected w...
- 4.2.6 Where liquid coolants are used, the detection of liquids in an equipment enclosure and provision of an alarm indication should be taken into account. For semiconductor converters, the flow of coolant should be monitored to operate an alarm in th...
- 4.2.7 Apparatus should be provided with suitable cable glands, bushings or conduit entries. All entries should maintain the degree of protection provided by the enclosure of the associated apparatus (see 8.2.1.8).
- 4.2.8 The means of fixing current-carrying parts should be independent of the means of making electrical connection thereto.
- 4.2.9 Apparatus should be provided with suitable terminals, clearly marked, placed in an accessible position convenient for external connections. The terminals should be effectively secured and should be so spaced and/or shielded as to minimize the ri...
- Enclosures containing delicate apparatus should be provided with means to allow easy termination of cables without exposing such apparatus to the possibility of damage. [Go to Page]
- 4.2.10 Enclosures of fixed apparatus which are liable to exceed a temperature of 80 C should be so located or guarded as to prevent persons coming accidentally into contact with such equipment.
- 4.3 Installation, location and protection of equipment [Go to Page]
- 4.3.1 Electrical equipment should, as far as practicable, be so placed that it is not exposed to risk of mechanical damage or excessive vibration. If equipment is installed in locations subject to vibration, e.g. steering compartments, it should be se...
- 4.3.2 Electrical equipment should be so selected and located or protected that the effects of exposure to sea air, water, steam, oil or oil fumes, spray, ice formation, etc., are minimized. Electrical equipment should be located well clear of boilers,...
- 4.3.3 Where sprinkler heads or water spraying devices are fitted for fire-fighting, the siting of electrical equipment should such that it is not likely to be seriously affected by the inadvertent operation of the extinguishing arrangement. For switch...
- 4.3.4 Horizontal rotating machines should, where practicable, be installed fore-and-aft to minimize the effects of rolling. Where a machine is installed athwartships or vertically, the design of bearings and the arrangement for their lubrication shoul...
- 4.3.5 Where an item of equipment or enclosure contains live parts that are not capable of being isolated by a single device, a warning notice should be placed in such a position that any person gaining access to live parts is warned of the need to use...
- 4.3.6 In ships where electric power is used for essential services, generators, switchgear, motors and associated control gear for such services should be so situated or protected that they continue to operate satisfactorily in the event of partial fl...
- 4.4 Electrical equipment in flammable and/or explosive dust atmospheres [Go to Page]
- 4.4.1 Owing to the potential dangers introduced by electrical equipment and the difficulty in maintaining its safe characteristics in service, such equipment should not be installed where flammable gases/vapours or explosive dusts are liable to accumu...
- 4.4.2 Where there is a risk of explosion from flammable gases/vapours, equipment should be of a safe type, certified for the gases/vapours involved and should conform to the BS EN 60079 series or an equivalent national or international standard.
- 4.4.3 Where there is a risk of explosion from combustible dusts, equipment should conform to BS EN IEC 60079-31 and BS EN 60079-14, or an equivalent national or international standard.
- 4.4.4 Electrical equipment for use in stores containing paint or other flammable fluids should be of a certified safe type. All switches and protective devices should interrupt all poles or phases and should be located in a non-hazardous area. Such sw...
- 4.4.5 Electrical equipment for use in other spaces/areas where flammable gases/vapours and/or explosive dusts are liable to accumulate or where explosive materials are handled or stored should be of a type acceptable to the appropriate authority.
- 5 Earthing and bonding [Go to Page]
- 5.1 System earthing [Go to Page]
- 5.1.1 Earthed neutral systems should be so designed that the potential earth fault current:
- 5.1.2 The earthing system adopted should take account of, and limit to acceptable values, possible harmonic circulating currents.
- 5.1.3 Low-voltage earthed neutral systems should be achieved by connecting the neutral point directly to earth. The earth loop impedance should be low enough to permit the passage of a current at least three times the fuse rating for fuse protected ci...
- 5.1.4 High-voltage earthed neutral systems should be achieved by inserting impedance in the neutral connection to earth to limit the earth fault current to an acceptable level. The prospective earth fault current should be at least three times the val...
- 5.1.5 Where an earthed system is divided into two or more sections, means for neutral earthing should be provided for each section.
- 5.1.6 All earthing resistors/impedances should be connected to the ship’s hull. In addition, earthing resistors/impedances should be bonded together on the hull side of the resistance/impedance. The means of bonding should be separate from that provid...
- 5.1.7 Efficient means should be provided for detecting defects in the insulation of the system. For systems where the earth fault current exceeds 5 A, automatic tripping devices should be provided.
- 5.2 Earthing of non-current-carrying parts [Go to Page]
- 5.2.1 Unless specifically included in the exemptions listed in BS IEC 60092-401, all exposed-conductive-parts and extraneous-conductive-parts should be bonded to the ship’s hull. The bonding should be such as to give a substantially equal potential an...
- 5.2.2 Extraneous-conductive parts, which are connected to the ship’s hull by permanent and reliable metal-to-metal joints of negligible impedance, should not be bonded by separate earthing conductors. Separate supplementary bonding should be provided ...
- 5.2.3 The earthing of installations in hazardous areas should conform to BS EN 60079-14.
- 5.3 Earth indication
- 5.4 Additional recommendations for ships with non-metallic hulls [Go to Page]
- 5.4.1 A main earth conductor bar should be provided at a suitable location (e.g. the main switchboard) to which all non-current-carrying parts not exempted in BS IEC 60092-401 should be connected.
- 5.4.2 The main earth conductor bar should be connected to the main earthing plate described in BS IEC 60092-401 by a copper conductor having a minimum cross-sectional area of 64 mm2, preferably of solid strip construction.
- 5.4.3 To minimize electromagnetic interference, earthing connections should be run with the associated power cables wherever practicable.
- 5.4.4 Earthing connections of equipment, which are sensitive to electromagnetic interference, should be made directly to the main earth conductor bar of the main earthing plate.
- 5.4.5 The earthing system and the lightning protective system (see Clause 20) should be run separately down to the pillars at the main earthing plate.
- 5.4.6 To dissipate possible charge build-up in ships with non-metallic hulls constructed of high resistivity materials (surface and volume resistivities greater than 108 ohms and 106 ohm-metres, respectively), all metallic objects over 0.6 m in length...
- 6 Application of diversity factors [Go to Page]
- 6.1 General [Go to Page]
- 6.1.1 The diversity factor for power circuits should take account of the known and anticipated conditions. The calculations should be based on the full load ratings of motors and the characteristics of the generators.
- 6.1.2 The diversity factor applied, where justifiable, to the loading calculation of cables, switchgear and generators supplying groups of winch motors or crane motors should be based upon the estimated duty cycle of the motors in the group, taking in...
- 6.1.3 All diversity factors should be taken as minima, and cables, switchgear and generators supplying winch motors and crane motors should be capable of carrying continuously (subject to voltage drop) the currents calculated by applying an appropriat...
- 6.1.4 Where the cables feeding winch motors and/or crane motors supply other equipment, the current upon which the cross-sectional area of the conductors of the cables is based should allow for the coincidence of the various loads and any calculated v...
- 6.2 Refrigerated containers
- 7 Distribution [Go to Page]
- 7.1 General [Go to Page]
- 7.1.1 If a cable is looped from board to board without passing through a protective device, the cable conductors should be of the same cross-section throughout.
- 7.1.2 Switches in conductors of insulated distribution systems should open all lines simultaneously.
- 7.2 Final circuits [Go to Page]
- 7.2.1 A final circuit may supply two or more cooking appliance where these are installed in one space; this circuit should have a rating exceeding 16 A, but not exceeding 32 A. In the absence of precise data, the current demand should be assessed as t...
- 7.2.2 In dry areas of accommodation spaces, and in spaces having similar environmental conditions, where socket-outlets conforming to BS 1363-2 are installed, they should be served by ring final circuits, each protected by a 30 A or 32 A fuse or circu...
- 7.2.3 Every final circuit should be separately connected to a distribution board or a switchboard.
- 7.2.4 Switches used to control emergency lighting should not be accessible to unauthorized persons.
- 7.2.5 Pilot lamps installed as an integral part of an appliance or accessory for essential services should be suitably protected such that a lamp circuit failure will not impact primary equipment function.
- 7.3 Navigation lights [Go to Page]
- 7.3.1 General [Go to Page]
- 7.3.1.1 Ships of every type and size should be provided with “steaming lights”, which comprise masthead, side, stern, anchor, not-under-command and, if applicable, special purpose lights.
- 7.3.1.2 Ships should be provided with primary and alternative lanterns for each of the navigation lights, except that alternative lights are not required for ships less than 24.4 m in length. Primary lanterns and alternative lanterns should be electric.
- 7.3.2 Primary electric steaming lanterns with electric alternatives [Go to Page]
- 7.3.2.1 Each light should be connected by a separate cable to a distribution board reserved for navigation lights, fitted in an accessible place and under control of the officer of the watch.
- 7.3.2.2 There should be two essentially separate power supply systems to the distribution board: one from the main switchboard and one from the emergency switchboard. Where a transitional source of emergency power is needed, the arrangements should be...
- 7.3.2.3 So far as is practicable, the arrangements should be such that a fire, fault or mechanical damage at any one point does not render both systems inoperative. Given that the systems inevitably come together at some point where the changeover can...
- 7.3.2.4 Each light should be controlled and protected in each insulated pole by a switch and fuse, or by a circuit-breaker mounted in the distribution board.
- 7.3.2.5 Each light should be provided with an automatic indicator to give an audible and/or visual alarm in the event of lamp failure. If a visual signal is used, which is connected in series with the steaming light, means to prevent failure of the in...
- 7.3.2.6 The use of junction boxes in navigation light circuits, other than those provided for connecting the lanterns to the fixed wiring of the electrical installation, should be avoided. Cables for different circuits should not use the same junction...
- 7.3.2.7 Where systems at reduced voltage (e.g. 24 V) are used, the voltage drop in cables should not exceed 6% of the nominal voltage.
- 7.3.3 Electric steaming lanterns with oil alternatives
- 8 Generating plant and motors [Go to Page]
- 8.1 Prime movers [Go to Page]
- 8.1.1 General [Go to Page]
- 8.1.1.1 Prime movers for driving generators should conform to the following applicable standards:
- 8.1.1.2 Where a change in operating ambient conditions is likely to significantly alter the relationship between the capabilities of the prime mover and driven generator, appropriate measures should be employed to prevent damage.
- 8.1.2 Governing characteristics [Go to Page]
- 8.1.2.1 Transient performance for all types of prime mover should at least meet the governing accuracy for Class G2 in BS ISO 8528-5.
- 8.1.2.2 Each prime mover should be fitted with an emergency overspeed device which operates at a speed not more than 15% above rated speed and has provision for tripping by hand.
- 8.1.2.3 The governor setting should be capable of adjustment both locally and from a remote switchboard.
- 8.1.2.4 Each combined prime mover, transmission system and generator should be designed to withstand without damage the effects of the most onerous short-circuit condition at the generator terminals when running at rated voltage and speed.
- 8.1.3 Lubrication
- 8.2 Generators and motors [Go to Page]
- 8.2.1 General [Go to Page]
- 8.2.1.1 Where continuous rating is inappropriate, generators and motors should be assigned ratings in accordance with the BS 4999 series or BS EN 60034-1, as applicable to their specified duty.
- 8.2.1.2 Where motors are to be operated on a non-sinusoidal and/or variable frequency supply, any additional heating should be such that it does not impair the service life of the motor.
- 8.2.1.3 Where cooling-water is used, the cooler should be so arranged as to minimize the risk of entry of water into the machine, whether by leakage or condensation in the heat exchanger.
- 8.2.1.4 Machines should be so constructed that when running at any and every working speed, all revolving parts are well balanced and capable of withstanding over-speeds required by the prime mover.
- 8.2.1.5 DC machines and their protective system should be so designed that they minimize damage in the event of short-circuit.
- 8.2.1.6 Every sleeve bearing should be fitted with an inspection cover and means for visual indication of level or flow or pressure, as appropriate to the type of lubrication employed.
- 8.2.1.7 Measures should be taken, if necessary, to avoid the circulation of currents between the shaft and bearings.
- 8.2.1.8 Machines should be located so that adequate space is provided to enable convenient access for cables and ease of their connection or termination (see 4.2.7).
- 8.2.2 Adjustment of generator voltage [Go to Page]
- 8.2.2.1 Where manual adjustment of terminal voltage is necessary or is provided for the satisfactory operation of generators, the facilities should be provided at the switchboard or at an appropriate control position.
- 8.2.2.2 For each generator, coupled to its prime mover at any permissible temperature within the working range, the means provided should be capable of adjusting the voltage at any load between no-load and full-load to within:
- 8.2.2.3 The excitation system provided in accordance with 8.2.2.1 and 8.2.2.2 should be capable of maintaining the voltage under steady-state conditions within ±2.5% of rated voltage for all loads between zero and rated load, within the range of power...
- 8.2.2.4 In the limit, the generating plant should have a transient voltage response such that the anticipated motor starting currents are accommodated without such voltage drop as would cause maloperation of or damage to other equipment.
- 8.2.3 Circulating currents and starting currents [Go to Page]
- 8.2.3.1 If generators are intended to run with their neutrals solidly connected together, or connected via a low impedance, the manufacturer(s) should be informed so that the generators can be designed to have a low value of harmonic voltage and/or to...
- 8.2.3.2 For every AC motor, the starting current and its duration should be compatible with the mechanical load, the overall characteristics of the supply system and the protective equipment. Each motor should be rated in accordance with its duty.
- 8.3 Shaft generator systems [Go to Page]
- 8.3.1 Performance
- 8.3.2 Construction
- 8.3.3 Lubrication [Go to Page]
- Where forced lubrication (pressure or gravity fed) is used on machines in or connected to the propulsion shaft line, temperature and pressure-measuring devices, or temperature and flow-measuring devices, should be fitted and arranged to operate an ala...
- 8.3.4 Alarms and indicators [Go to Page]
- Where a switch is provided for silencing an audible alarm(s), a visual warning device should be automatically switched on to indicate acceptance of the alarm(s).
- 8.4 Additional recommendations for shaft generating systems [Go to Page]
- 8.4.1 The generating system should be capable of continuously delivering the power required under all ship manoeuvring conditions, including the propeller being stopped.
- 8.4.2 The generating system should be at least as effective and reliable as independent generating sets.
- 8.4.3 The generating system should be such that with any one generator or its prime mover out of operation, the remaining generator(s) are capable of providing the electrical services necessary to start the main propulsion plant from a dead ship condi...
- 8.5 Other shaft generators
- 9 Construction of cables [Go to Page]
- 9.1 If the particular application allows the use of solid wire conductors, then cables using class 2 or class 5 conductors in accordance with to BS EN 60228 should be used.
- 9.2 The shape of the cable should be such that its entry into an enclosure does not impair the enclosure’s specified degree of protection.
- 9.3 Where cables are required to operate in an area where contamination by oil is likely to occur, the type of oversheath selected should be of an “enhanced oil resistance” grade. In cases where the contamination is severe, the advice of the cable man...
- 9.4 Every core of a single, twin or multi-core cable for use as fixed wiring should be identifiable at its terminations and, preferably, throughout its length.
- 10 Selection and installation of cables [Go to Page]
- 10.1 Determination of the cross-sectional areas of conductors
- 10.2 Protective covering of cables
- 10.3 Cable runs
- 10.4 Installation in metallic pipes, conduits or trunking [Go to Page]
- 10.4.1 Conduits and conduit fittings should, with the exception of inspection and draw-in boxes (see 10.4.2), conform in all respects to BS EN 61386-1 and BS EN IEC 61386-21, BS EN IEC 61386-22 or BS EN IEC 61386-23, as applicable, and should be heavy...
- 10.4.2 Inspection and draw-in boxes should be of metal construction and should be in rigid electrical and mechanical connection with the conduits. The boxes should, in addition, conform to BS EN 61386-1 or BS EN 50085-1, as applicable. For steel condu...
- 10.4.3 A space factor of 40% should be applied to installations where the cables are not drawn round more than two 90 bends conforming to BS EN 61386-1 or BS EN 50085-1, as applicable. Where there are more than two such bends, an appropriate reductio...
- 10.5 Cable ends
- 10.6 Cables for special applications
- 11 Tables of cable current ratings [Go to Page]
- 11.1 General
- 11.2 Voltage drop
- 12 Motor control gear [Go to Page]
- 12.1 Construction and temperature limits [Go to Page]
- 12.1.1 The construction, rating and testing of control gear should be in accordance with BS IEC 60092-302-2, BS EN IEC 62271-106, BS EN IEC 62271-200 or BS EN 60947-4-1, as applicable.
- 12.1.2 Glazed windows of enclosing cases should be as small as practicable, consistent with their purpose, and suitable protection should be arranged, where necessary, against accidental breakage.
- 12.2 Electric motors [Go to Page]
- 12.2.1 Every electric motor with a rating of more than 0.5 kW should be provided with efficient means of starting and stopping, the latter so placed as to be easily operated by the person controlling the motor.
- 12.2.2 Means should be provided to prevent automatic re-starting after a stoppage due to a drop in voltage or complete failure of supply, where unexpected re-starting of the motor is undesirable.
- 12.2.3 Means of isolation should be provided, suitably placed, and so connected that all voltages are removed from the motor and all apparatus, including any associated automatic circuit-breaker.
- 12.2.4 Where necessary for safety, local stopping facilities should be provided.
- 12.2.5 Where a single master-starter system (i.e. a starter used for controlling a number of motors successively) is used, the apparatus should provide under-voltage and overcurrent protection and means of isolation for each motor not less effective t...
- 12.2.6 Emergency stop controls for motor-driven fuel-oil transfer and fuel-oil pressure pumps should be provided at a readily accessible point outside the compartments in which the pumps are situated. The controls should be of the manual re-set type a...
- 12.2.7 All power ventilation, except machinery and cargo space ventilation and any alternative ventilation specially provided for control stations outside the machinery spaces, should be fitted with controls so grouped that any fans are capable of bei...
- 12.2.8 Motor-driven pumps designed to discharge above the water line in the way of lifeboat launching should be provided with emergency stop controls installed in locked boxes having breakable covers, e.g. glass, conveniently located. The controls sho...
- 12.3 Lifts [Go to Page]
- 12.3.1 Lift electrical equipment should conform to the appropriate part of the BS 5655 series.
- 12.3.2 Lifts, other than those used exclusively for goods, should be arranged so that in the event of failure of the main supply, they deck automatically using the emergency supply and should then allow the gates to be opened, or should be provided wi...
- 12.3.3 Unless the emergency generator is arranged to start automatically on mains failure, the emergency supply should be taken to include the 30 min transitional battery, where fitted.
- 12.3.4 One lamp in each lift and the alarm facility should be supplied from an emergency power source.
- 12.4 Magnetic brakes [Go to Page]
- 12.4.1 Series-wound and compound-wound brakes should release on first-step starting current of the motor. Series-wound brakes should hold off under all working conditions, including light running. Equipment that provides electric controlled lowering s...
- 12.4.2 The temperature rise of coils when tested in accordance with the brake rating should not exceed that permitted on motors with which they are being used. Where the coils are in close proximity to the lining, the brakes should be tested under con...
- 12.5 Magnetic clutches
- 13 Batteries [Go to Page]
- 13.1 General [Go to Page]
- 13.1.1 The temperature of the battery should be maintained within the range 15 C to 50 C, or as recommended by the manufacturer.
- 13.1.2 Each battery should be provided with a durable name-plate securely attached or, alternatively, fitted adjacent to the battery, bearing the maker’s name and type designation, the ampere-hour rating at some specific rate of discharge (preferably ...
- 13.1.3 All batteries should be arranged to facilitate ease of installation, replacement and, where necessary, maintenance. Each cell or crate of cells should be accessible from the top and at least one side.
- 13.1.4 Where a battery consists of single cells assembled in crates or trays or upon a stand or stands of wood or other suitable material, such crates and trays should be provided with means to facilitate handling. Crates and trays should not exceed 1...
- 13.1.5 All fittings should be non-corrodible or should be treated with electrolyte-resistant material.
- 13.2 Construction
- 13.3 Location [Go to Page]
- 13.3.1 No battery compartment should form a means of access to any other compartment.
- 13.3.2 Where lead acid and alkaline batteries are installed in the same compartment or on the same platform, separate tools, such as hydrometers and topping-up devices, should be provided.
- 13.3.3 Battery compartments should have gas-tight boundaries where they adjoin accommodation or service spaces. They should be arranged with access from the open deck.
- 13.4 Ventilation [Go to Page]
- 13.4.1 The ventilation system for battery boxes and compartments should be separate from other ventilation systems and the ducts should lead to a location in the open air where any gases can be safely diluted. The location should be away from possible...
- 13.4.2 Batteries in rooms, compartments or boxes connected to a charging device with a total maximum power output of more than 2 kW should be ventilated by mechanical exhaust.
- 13.4.3 Where lockers or boxes are provided for batteries in machinery spaces and other well-ventilated compartments, the duct should terminate not less than 900 mm above the battery enclosure.
- 13.4.4 Boxes for batteries should have ventilation openings near the top to permit escape of gas. Holes for air inlet should be provided on opposite sides of the box as a minimum. The entire box, including openings for ventilation, should be sufficien...
- 13.4.5 All openings through battery compartment bulkheads or decks, other than ventilation openings, should be effectively sealed to reduce the possibility of escape of gas from the battery compartment.
- 13.5 Electrical installations in battery compartments and rooms [Go to Page]
- 13.5.1 Luminaires should be permanently wired and fitted outside the space so that the space is illuminated through permanently fixed lenses or ports fitted in the bulkhead or deck, so arranged to maintain the gas-tight integrity of the compartment.
- 13.5.2 Cables should not be installed in battery compartments unless they form part of intrinsically safe circuits or are serving permitted equipment within the compartment.
- 13.5.3 Cable penetration arrangements should maintain the gas-tight integrity of the battery compartment.
- 13.6 Sealed batteries [Go to Page]
- The use of lithium batteries should be in accordance with BS EN IEC 62619.
- 13.7 Valve-regulated batteries [Go to Page]
- 13.7.1 General [Go to Page]
- 13.7.1.1 Valve-regulated lead-acid batteries should conform to BS EN 60896-22 and BS EN 61056-1. Nickel-cadmium batteries should conform to BS EN IEC 61951-1 and BS EN 60622.
- 13.7.1.2 Where other standards are used, precautions should be taken to minimize the risk of a release of gas under normal conditions and risk due to disruption by explosive force in abnormal conditions.
- 13.7.1.3 Boxes or lockers containing valve-regulated batteries should conform to 13.4.4.
- 13.7.2 Charging facilities [Go to Page]
- 13.7.2.1 Where valve-regulated batteries are installed in accordance with BS EN 60623 and BS EN 60896-22, a device independent of the normal charging arrangements should be provided to sense and alarm in the event of gas evolution in excess of the man...
- 13.7.2.2 A suitable warning plate should be fitted to the charger stating: “Isolate charger before working on battery connections.”
- 13.7.2.3 In the case of constant voltage changes, temperature compensation should be taken into account in accordance with the battery manufacturer’s recommendations.
- 14 Heating and cooking appliances [Go to Page]
- 14.1 General [Go to Page]
- 14.1.1 Electric heating and cooking appliances should conform to BS EN 60335-1, BS EN 60335-2-36, BS EN 60335-2-37, BS EN 60335-2-38 and BS EN 60335-2-39.
- 14.1.2 All combustible materials in the vicinity of heating and cooking appliances should be protected by suitable non-combustible and thermal-insulating materials.
- 14.1.3 Every heating and cooking appliance, whether portable or fixed, should be controlled locally by a fixed switch. Where a socket-outlet is provided, it should be connected between the switch and the appliance. When in the “off” position, control ...
- 14.1.4 A means by which power to the galley can be cut off in the event of fire should be fitted outside the galley exits in positions not likely to be made inaccessible by such a fire.
- 14.1.5 Space heaters should be of the convector type, and be equipped with means to interrupt the current if the temperature exceeds the permissible limit.
- 14.2 Trace and electric surface heating systems [Go to Page]
- 14.2.1 Trace heating systems should conform to BS EN 62395-2.
- 14.2.2 Systems should use devices suitable for locations with a high probability of the presence of water and a high risk of mechanical damage. They should be provided with overcurrent protection, residual current protection with trip indication, adeq...
- 14.2.3 Cable or tape units should be provided with either metallic sheath, braid or wire armour.
- 14.2.4 The cable or tape units should be supplied from an isolating transformer or transformers with secondary circuit earthed and having a secondary voltage not exceeding 254 V.
- 14.2.5 The RCCB should conform to BS EN 61008-1 and should have a rated residual operating current not exceeding 30 mA.
- 14.2.6 In situations where the cable or tape units are liable to mechanical damage, they should be provided with suitable protection.
- 14.2.7 Notices should be provided indicating the location of cables or tapes, and warning personnel not to stand on traced pipes.
- 14.2.8 Trace heating systems which are installed in hazardous areas should additionally conform to BS 60079-14.
- 15 Semiconductor converters for power purposes [Go to Page]
- 15.1 In addition to the requirements in BS IEC 60092-304, the following should be taken into account.
- 15.2 Filters fitted in the power circuit for EMC purposes should be so designed that they are protected against overloading by energy generated elsewhere in the connected system.
- 15.3 If the cooling water is in contact with live heatsinks, a method for controlling its conductivity should be provided. An alarm should be activated if the conductivity exceeds a pre-set value.
- 16 Transformers
- 17 Accessories [Go to Page]
- 17.1 General [Go to Page]
- 17.1.1 Cable entries should conform to the class of enclosure of the accessory.
- 17.1.2 Where there is the possibility of electrolytic corrosion between a metal enclosure and the surface upon which it is mounted, suitable insulating material should be inserted and separate means should be provided to bond the case to earth.
- 17.2 Switches [Go to Page]
- 17.2.1 Switches should conform to the applicable requirements of the BS EN 60669 series. Where the ambient and/or load parameters exceed those in the BS EN 60669 series, other appropriate national or international standards should be applied.
- 17.2.2 In galleys, laundries, bathrooms, machinery and other similar spaces, switches should be of watertight or of all-insulated construction to protect against mositure.
- 17.2.3 On weather decks, switches should be of watertight construction IP56 and cable entries provided with watertight glands.
- 17.2.4 Every switch or other means of control or adjustment should be so situated as to be normally inaccessible to a person using a fixed bath or shower, except for electric shaver supply units conforming to BS EN 61558-2-5 or insulating cords of cor...
- 17.2.5 Every switch not specially designed to break an inductive load of its full rated capacity should:
- 17.3 Socket-outlets and plugs [Go to Page]
- 17.3.1 Socket-outlets and plugs should conform to the relevant requirements of the BS 1363 series or BS EN 60309-2, as appropriate.
- 17.3.2 Where differing distribution systems supplying socket-outlets are in use, the socket-outlets and plugs should be of such design that an incorrect connection cannot be made.
- 17.3.3 All three-phase socket-outlets should be of the same phase rotation.
- 17.3.4 Socket-outlets should not be installed below the floor of machinery spaces and in closed fuel and lubricating oil separator rooms.
- 17.3.5 In a space containing a fixed bath or shower, there should be no socket-outlets and there should be no provision for connecting a portable appliance, except where it is a shaver supply unit conforming to BS EN 61558-2-5.
- 17.3.6 Socket-outlets for use with electric shavers should be incorporated in a shaver supply unit conforming to BS EN 61558-2-5 when installed in bathrooms or wash places. When installed in other locations they should:
- 17.3.7 Every plug containing a fuse should be non-reversible and so designed and arranged that no fuse can be connected in an earthed conductor.
- 17.3.8 Where the supply is DC, each socket-outlet should be controlled by a switch immediately adjacent thereto or combined therewith. Where the supply is AC and the plug is readily withdrawable, such a switch need not be provided, except for sockets ...
- 18 Communication and navigation aids [Go to Page]
- 18.1 All communication and navigation aid systems should operate from the ship’s main source of electrical power. Additionally, the systems required to be carried should be provided with access to the ship’s emergency source of electrical power.
- 18.2 Radio communication systems should also have access to a reserve source of energy.
- 18.3 The main emergency and reserve sources of energy for the communication and navigation aids should be conditioned power supplies suitable for the bridge and deck zone in accordance with BS IEC 60533.
- 19 Control and instrumentation [Go to Page]
- 19.1 Environmental and supply conditions [Go to Page]
- 19.1.1 Power supplies [Go to Page]
- 19.1.1.1 All circuits providing emergency services should receive supplies from sources which are available under both normal and emergency conditions.
- 19.1.1.2 In the event of failure of supply to the engine-room telegraph, indication should be given on the bridge.
- 19.1.1.3 Supplies to programmable electronic systems should be in accordance with 19.3.
- 19.1.2 Electromagnetic compatibility (EMC) [Go to Page]
- 19.1.2.1 Each system should incorporate, as necessary, suitably screened equipment, earthing and arrangement of cabling such that any induced interference between systems in no way impairs the proper effective operation of these systems at all times.
- 19.1.2.2 Where systems are connected to a common source of supply, they should be so arranged that no detrimental effects are induced onto the supply which could impair the operation of other apparatus connected on the supply.
- 19.1.2.3 Equipment should meet the requirements of BS IEC 60533 or BS IEC 60945.
- 19.2 Computer-based systems – safety applications [Go to Page]
- 19.2.1 Computer systems which also provide safety functions (or in the event of their failure would have safety implications affecting the ship, its personnel or the environment) and which are not backed-up by non-computer-based devices should be subj...
- 19.2.2 Computer-based systems used for essential services, or which are connected directly or indirectly to an essential service, should be protected from unauthorized/uncontrolled alteration of system configurations, programs or data, from both onboa...
- 19.3 Power supplies [Go to Page]
- 19.3.1 Power supplies to processors should be arranged to provide automatic transfer facilities from the normal to an alternative supply of suitable quality, e.g. smoothed and stabilized, when necessary.
- 19.3.2 The operation of transfer arrangements should not interrupt or interfere with the safe operation of the ship.
- 19.3.3 The following should be checked:
- 20 Lightning protection [Go to Page]
- 20.1 Protective systems
- 20.2 Earth terminals
- 21 Systems operating at above 1 kV AC [Go to Page]
- 21.1 General [Go to Page]
- 21.1.1 Where a lower-voltage system is supplied from a high-voltage system, precautions should be taken to prevent the lower-voltage system being charged by leakage from the high-voltage system.
- 21.1.2 Access to high-voltage equipment by unauthorized personnel should be prevented (by the provision of locks and keys, warning notices, etc.).
- 21.1.3 All keys provided for access should be available to authorized personnel only.
- 21.1.4 Only authorized personnel should carry out maintenance, repair and calibration of high-voltage equipment using a “permit to work” system in accordance with BS 6626.
- 21.2 High-voltage tests [Go to Page]
- 21.2.1 General
- 21.2.2 Rotating machines
- 21.3 Creepage and clearance distances
- 21.4 Switchgear, control gear and fuse gear
- 22 Dynamic positioning (DP) [Go to Page]
- 22.1 General
- 22.2 DP control system power supplies
- Annex A (informative) Guidance on the selection and use of socket-outlets and welding equipment [Go to Page]
- A.1 Voltages for use with AC handheld equipment [Go to Page]
- A.1.1 Conditions vary to such an extent and are so difficult to define that precise rules governing the application of appropriate voltages for portable equipment in various locations are not practicable. Furthermore, the susceptibility of individuals...
- A.1.2 In dry areas of accommodation spaces where the risk is not abnormal, supplies as specified in BS IEC 60092-201:2019, Table 3(3) are satisfactory for cabin fans, vacuum cleaners, table lamps, etc. Additional safety, if considered necessary, can b...
- A.1.3 For supplies to electric shavers, see 17.3.6.
- A.1.4 For hand lamps, 24 V is recommended.
- A.1.5 In some circumstances, a supply not exceeding 115 V, obtained from a transformer of which the mid-point of the secondary (115 V) winding is connected to earth, thus limiting the shock risk to earth to a maximum of 60 V, might be appropriate.
- A.1.6 Handheld tools can be obtained for 50 V but current-carrying difficulties can arise if lower voltages are chosen. If these supplies are derived from local isolating transformers limited to the supply of only one appliance, safety is further impr...
- A.1.7 Where supplies are provided under the terms of BS IEC 60092-201:2019, Table 3(3), it is advisable that the loading of each isolated secondary circuit is limited to 5 kVA supplying only one socket-outlet.
- A.1.8 Under particular conditions, any AC voltage, even as low as 50 V, can be fatal. Even lower voltages can cause injury due to being thrown off balance by a shock. Very adverse conditions occur where personnel and equipment can become damp while su...
- A.1.9 For circuits having adequate earth return path (i.e. one point of the supply is connected to earth), RCCBs in addition to other precautions can be used.
- A.2 Choice of handheld equipment
- A.3 Voltages for use with AC portable and transportable equipment [Go to Page]
- A.3.1 The guidance for handheld equipment in A.2 is to be followed as far as practicable.
- A.3.2 It is recognized, however, that the limits of voltage given are not always practicable for equipment (submersible pumps, deck scalers, refrigerated containers, etc.). In these cases, where three-phase supplies up to 500 V might be involved, the ...
- A.4 Electric shock hazard in the use of electric arc welding equipment [Go to Page]
- A.4.1 The risk from electric shock in the use of electric arc welding equipment in certain special locations, for example, as described in A.1.8, is not always recognized.
- A.4.2 Since the effect of shock from direct current is less (at the operating voltages used) than with alternating current, the use of welding sets having a DC output, especially those incorporating DC generators providing an open circuit (idling) vol...
- A.4.3 Voltage reduction safety devices which limit the “idling” voltage to 25 V or less are also available for use with alternating current electric arc welding plant.
- A.4.4 These safety devices are intended to apply the idling voltage only until there is contact between the electrode and the “work” when the full open circuit voltage becomes available to strike the arc. Once struck, welding continues in the normal w...
- A.4.5 Electrode holders of the fully insulated type are to be used.
- A.4.6 When joints in the cables are necessary, fully insulated connectors are to be used, designed such that live parts are not exposed when disconnected. A “go and return” system where two cables are used from the welding set with one cable solidly c...
- A.4.7 Means whereby the current can rapidly be cut off from the electrode holder are to be in place in case the operator gets into difficulties. Means of disconnection are to be available to the welder for use when changing electrodes.
- Annex B (informative) Guidance on the treatment of the neutral point [Go to Page]
- B.1 Methods of treating the neutral point in electrical systems [Go to Page]
- B.1.1 The neutral point
- B.1.2 The neutral point under fault conditions
- B.1.3 Neutral earthing methods [Go to Page]
- B.1.3.1 On occurrence of a fault from line to earth, the steady-state and transient voltages to earth and fault currents vary with the impedance between the neutral point and earth. This impedance is dependent on the treatment of the neutral point and...
- B.1.3.2 Although not intentionally connected to earth, the so-called “unearthed” or “isolated” system is in fact capacitively earthed by the distributed capacitance to earth of the phase conductors throughout the system, together with any interference...
- B.1.3.3 The principal features of these methods are given in Figure B.1.
- B.1.4 Marine electrical systems [Go to Page]
- B.1.4.1 Marine electrical systems have a number of significant characteristics which differentiate them from typical land-based systems. These need to be borne in mind when considering neutral earthing of marine systems.
- B.1.4.2 The zero and positive sequence impedance of AC generators, which are the usual sources of power, are such that line to neutral fault current can significantly exceed the symmetrical three-phase fault value. This is of importance to the rating ...
- B.1.4.3 The interconnection of the neutral points of generators, particularly those of different sizes or different winding configurations, or even identical generators with different loadings, can give rise to undesirable circulating harmonic current...
- B.1.4.4 Distribution circuits are geographically compact and distribution is by cable. The proximity of the cables to the hull structure and also of machine windings to earthed stator cores unavoidably gives rise to significant phase-to-earth capacita...
- B.1.4.5 Fault power factors are low, with the result that the ratio of peak asymmetrical current to RMS symmetrical current is high and tends to the maximum ratio of .
- B.1.4.6 System natural resonant frequencies are high, typically 5 kHz–10 kHz. At these frequencies, the oscillatory circuit is usually over damped, with the result that oscillatory overvoltages are unlikely to occur.
- B.1.4.7 Earth return impedances are low due to the metal structure.
- B.1.4.8 The wet, salty, high vibration level operating environment is harsh and might cause earth faults to occur, particularly in exposed electrical fittings.
- B.1.4.9 Because comprehensive spares might not be carried on board and maintenance personnel might not be sufficiently specialized, the diagnosis of faults and their subsequent repair might not be undertaken until return to port.
- B.2 Selection of neutral earthing method [Go to Page]
- B.2.1 General [Go to Page]
- B.2.1.1 In view of the wide variety of types and sizes of ships and their associated electrical installations, there is no single “best” method for treating the neutral point in marine electrical power systems. Good, safe, correctly engineered install...
- B.2.1.2 In order to select a method for a given application, a careful assessment is to be made of the relative importance of all technical, operational and commercial factors (see Figure B.1). Subjective judgements are mostly unavoidable, but the fol...
- B.2.2 Factors not significant [Go to Page]
- B.2.2.1 Although important in their own right, certain factors apply equally, however the neutral point is treated and so can be discounted when selecting between methods.
- B.2.2.2 Electric shock – phase to earth
- B.2.2.3 Overvoltages
- B.2.2.4 System voltage
- B.2.3 Significant factors [Go to Page]
- B.2.3.1 Earth faults
- B.2.3.2 Continuity of supply
- B.2.3.3 Switchgear rating
- B.2.3.4 Availability of suitable electrical equipment
- B.2.3.5 Fault location
- B.2.3.6 Fire risk
- B.2.3.7 Flash hazard
- B.2.4 Applicability to marine electrical systems [Go to Page]
- B.2.4.1 Unearthed neutral systems
- B.2.4.2 High reactance earthed neutral systems
- B.2.4.3 High resistance earthed neutral systems
- B.2.4.4 Low resistance or low reactance earthed neutral systems
- B.2.4.5 Solidly earthed neutral systems
- B.3 Good practice for the selected neutral earthing method [Go to Page]
- B.3.1 Unearthed neutral systems [Go to Page]
- B.3.1.1 To avoid jeopardizing the main power system through final circuit earth faults, localized earthed systems for supplying lighting and hotel services can be used.
- B.3.1.2 At the design stage, assess what actions can be taken to ease the fault location process by, for example:
- B.3.1.3 Estimate the system capacitance fault current at the design stage and then measure it to check that the risk of fire is acceptable.
- B.3.1.4 Assess the benefits offered by phase segregation barriers to reduce the likelihood of earth faults becoming phase faults.
- B.3.1.5 Fit double pole switches.
- B.3.1.6 Alert the operating staff to the need to remove earth faults as quickly as possible by specifying that a warning notice needs to be installed adjacent to the earth fault indication lamps.
- B.3.2 Earthed neutral systems [Go to Page]
- B.3.2.1 General
- B.3.2.2 Solidly earthed neutral
- B.4 Calculation for damping of oscillatory overvoltages [Go to Page]
- B.4.1 Basis
- B.4.2 Procedure [Go to Page]
- B.4.2.1 For each combination of generators, motors, cable lengths, etc., produce an equivalent R-L-C circuit and calculate its natural frequency, fo, using the formula:
- B.4.2.2 Establish the sources of loss in the circuit and convert to an equivalent resistance “Re” as follows, noting that the losses are to be obtained at the natural frequency of the system.
- B.4.2.3 Check for damping.
- Annex C (informative) Guidance on electromagnetic compatibility (EMC) [Go to Page]
- C.1 General
- C.2 Types of interference
- C.3 Modes of interference propagation and coupling to interference sources [Go to Page]
- C.3.1 Conducted interference
- C.3.2 Types of mutual coupling
- C.3.3 Coupling effects of earth currents
- C.4 Installation practice designed to reduce interference transmission and pick-up [Go to Page]
Copyright 2024 Compu-tecture, Inc.
All Rights Reserved.
About Us /
Careers /
support@madcad.com /
1.800.798.9296