Section 1 General requirements

1.1.1 The requirements of Pt 16, Ch 2, 1 General requirements and Pt 16, Ch 2, 21 Testing and trials are, in general, applicable to all the craft types indicated in Pt 1, Ch 2, 2.1 Applicable craft types, with the exception of cargo craft, patrol and pilot craft, workboats and other similar craft of less than 500 tons gross tonnage for operation in Service Groups 1 to 3, and for yachts less than 500 gt, which are covered in Pt 16, Ch 2, 20 Cargo craft, patrol and pilot craft, workboats and other similar craft of less than 500 tons gross tonnage for operation in Service Groups 1 to 3, and yachts less than 500 gt.

1.1.2 Whilst this Chapter applies to the electrical engineering equipment and systems on special service craft intended to be classed, attention should also be given to any relevant Statutory Regulations of the National Authority of the country in which the craft is to be registered and the Code of Safety for High Speed Craft.

1.1.3 Electrical services required to maintain the craft in a normal seagoing, operational and habitable condition are to be capable of being maintained without recourse to the emergency source of electrical power.

1.1.4 Electrical services essential for safety are to be maintained under declared normal and reasonably foreseeable abnormal conditions.

1.1.5 The safety of passengers, crew and craft from electrical hazards is to be ensured.

1.1.6 Consideration will be given to special cases or to arrangements which are equivalent to the Rules.

1.2.1 The documentation described in Pt 16, Ch 2, 1.2 Documentation required for design review 1.2.2 to Pt 16, Ch 2, 1.2 Documentation required for design review 1.2.13 is to be submitted for design review.

1.2.2 Single line diagrams of main, emergency and transitional power and lighting systems which are to include:

1. ratings of machines, transformers, batteries and semiconductor converters;

2. all feeders connected to the main and emergency switchboards;

3. section boards and distribution boards;

4. insulation type, size and current loadings of cables;

5. make, type and rating of circuit breakers and fuses;

6. details of harmonic filters (where fitted); and

7. details of power supply arrangements used for control systems.

1.2.3 A functional description of operation of the main, emergency and transitional electrical power systems, which is to include:

1. the operating philosophy of the main, emergency and transitional electrical power systems under normal and reasonably foreseeable abnormal conditions:

2. degraded modes of operation;

3. load management and load sharing philosophy; and

4. protection philosophy.

1.2.4 An earthing philosophy document that defines the basic approach to be taken for earthing the electrical power systems and all electrical loads.

1.2.5 Simplified diagrams of generator circuits, inter-connector circuits and feeder circuits showing:

1. protective devices, e.g. short circuit, overload, reverse power protection;

2. instrumentation and synchronising devices;

3. preference tripping;

4. remote stops and fire safety stops; and

5. earth fault indication/protection.

1.2.6 Calculations of short circuit currents at main, emergency and transitional switchboards and section boards, including those fed from transformers, with details of circuit breaker and fuse operating times and discrimination curves showing compliance with Pt 16, Ch 2, 6.1 General and Pt 16, Ch 2, 11.6 Conductor size 11.6.2.

1.2.7 Where required by Pt 16, Ch 2, 8.1 General 8.1.1, the hazards resulting from electric arcs within electrical equipment and their consequences for personnel are to be identified, and at least the following supporting evidence is to be submitted:

1. system design;

2. operating philosophies, e.g. manual or automatic control, local or remote operation;

3. general arrangement plans for switchboards, section boards and distribution boards, see also Pt 16, Ch 2, 1.3 Documentation required for supporting evidence 1.3.5;

4. general arrangement plans for the space in which the electrical equipment to be assessed are located, showing:

   1. access to adjacent spaces;

   2. the location of the electrical equipment;

   3. ventilation arrangements for air-conditioning and/or the extraction of smoke, gas and vapours resulting from electric arcs; and

   4. positions within the space in which the electrical equipment is located where personnel will be performing tasks, e.g. switching, equipment maintenance, instrument observation or cleaning, or where personnel could be reasonably expected to enter;

5. calculations in accordance with Pt 16, Ch 2, 8.3 Calculations to be submitted;

6. system operating procedures; and

7. details of defined additional safety measures to be taken during activities.

1.2.8 For battery installations, arrangement plans and calculations to show compliance with Pt 16, Ch 2, 12 Batteries.

1.2.9 A schedule of batteries fitted for use for emergency and essential services, giving details of:

• type and manufacturer's type designation;
• voltage and ampere-hour rating;
• location;
• equipment and/or system(s) served;
• maintenance/replacement cycle dates;
• date(s) of maintenance and/or replacement; and
• for replacement batteries in storage, the date of manufacture and shelf life, with accompanying battery replacement procedure documentation to show compliance with Pt 16, Ch 2, 12.7 Recording of batteries for emergency and essential services.

1.2.10 Details of electrically-operated fire, craft, crew and passenger emergency safety systems which are to include typical single line diagrams and arrangements, showing main vertical and, where applicable, horizontal fire zones and the location of equipment and cable routes, including identification of relevant high fire risk areas, to be employed for:

1. emergency lighting;

2. accommodation fire detection, alarm and extinction systems;

3. Fixed water-based local application fire-fighting systems;

4. public address system;

5. general emergency alarm;

6. watertight doors, shell doors and other electrically operated closing appliances; and

7. low location lighting.

1.2.11 Evidence of the suitability of electrical and electronic equipment for use in protected areas and adjacent areas, as required by Pt 16, Ch 2, 17.3 Fixed water-based local application fire-fighting systems 17.3.9 and Pt 16, Ch 2, 17.3 Fixed water-based local application fire-fighting systems 17.3.10, including a schedule of electrical and electronic equipment located in protected areas and adjacent areas, and general arrangement plans showing the coverage of the protected areas and adjacent areas. See also Pt 16, Ch 2, 1.11 Location and construction.

1.2.12 Schedule of normal and emergency operating loads on the system estimated for the different operating conditions expected. The following details are to be provided to meet this requirement:

1. a description of the expected operating profiles (e.g. the number of generating sets connected when manoeuvring, at sea, etc.), including as required by Pt 5, Ch 2, 1.1 General 1.1.1; and

2. a schedule of the normal and emergency operating loads, which is to state the kilowatt rating of each load and a load factor between 0 and 1 that reflects:

   1. the duty cycle of the load; and

   2. the proportion of its maximum rating at which the load is expected to operate.

1.2.14 For ships with hybrid electrical power systems as detailed in Pt 16, Ch 2, 23 Hybrid electrical power systems the following documentation is to be submitted for design review either uniquely or integrated with other submitted information:

Information required for all hybrid electrical power systems:

1. A functional description of the electrical distribution systems and equipment that details compliance with the performance criteria and system capability and functionality under defined normal and reasonably foreseeable abnormal conditions including:
   1. degraded modes of operation;
   2. load management and load sharing philosophy;
   3. earthing philosophy;
   4. system electrical protection philosophy;
   5. system stability; and
   6. converter switching actions.
2. Definition of system performance targets (see Pt 16, Ch 2, 23.5 Hybrid electrical power system performance - System performance targets);
3. Definition of dependability principles (see Pt 16, Ch 2, 23.6 Hybrid electrical power system performance - Dependability principles);
4. Calculations supporting the size and rating of stores of electrical energy (see Pt 16, Ch 2, 23.6 Hybrid electrical power system performance - Dependability principles 23.6.7);
5. Risk assessment in support of there being no dedicated emergency source of power when this is proposed (see Pt 16, Ch 2, 23.8 Hybrid electrical power system performance - Emergency source of electrical power 23.8.2);
6. Details of any arrangements for external sources of power to charge onboard stores of electrical energy (see Pt 16, Ch 2, 23.9 Hybrid electrical power system performance - External source of electrical power 23.9.3);
7. Voltage rate of rise times for pulse width modulated converters (see Pt 16, Ch 2, 23.11 Hybrid electrical power system components - Source of electrical power 23.11.6);
8. Risk assessment in support of active fault current limiting devices when this is proposed (see Pt 16, Ch 2, 23.15 Hybrid electrical power system components - Distribution system 23.15.11);
9. Technical description of energy management functionality (see Pt 16, Ch 2, 23.16 Hybrid electrical power system components - Energy management 23.16.4 and Pt 16, Ch 2, 23.16 Hybrid electrical power system components - Energy management 23.16.7);
10. Technical description of arrangements for power quality monitoring (see Pt 16, Ch 2, 23.17 Transversal requirements 23.17.6);
11. Power system integration procedure (see Pt 16, Ch 2, 23.18 Power system development and integration - General);
12. System operational concept (see Pt 16, Ch 2, 23.19 Power system development and integration - System operational concept);
13. Technical description of operating modes (see Pt 16, Ch 2, 23.20 Power system development and integration - Operating modes);
14. Validated specifications of system components (see Pt 16, Ch 2, 23.22 Power system development and integration - System components);
15. Results of energy flow analysis (see Pt 16, Ch 2, 23.23 Power system development and integration - Energy flows);
16. Results of power system analysis (see Pt 16, Ch 2, 23.24 Power system development and integration - Power system analysis);
17. Definition of safety functions (see Pt 16, Ch 2, 23.25 Power system development and integration - Safety functions);
18. System FMEA (see Pt 16, Ch 2, 23.27 Power system development and integration - System Failure Modes and Effects Analysis (FMEA));
19. System operating instructions (see Pt 16, Ch 2, 23.28 Power system development and integration - Operating instructions);
20. Description and verification of ship-specific Operator training needs (see Pt 16, Ch 2, 23.29 Power system development and integration - Operator training); and
21. Description of through-life system integration roles and responsibilities (see Pt 16, Ch 2, 23.30 Power system development and integration - Through-life accountability).

Additional information required for Hybrid Power (+) notation systems:

1. Dependability assessment (see Pt 16, Ch 2, 23.6 Hybrid electrical power system performance - Dependability principles);
2. Technical description of arrangements for automatic earth fault location (see Pt 16, Ch 2, 23.15 Hybrid electrical power system components - Distribution system 23.15.16);
3. Technical description of arrangements for power quality degradation detection (see Pt 16, Ch 2, 23.15 Hybrid electrical power system components - Distribution system 23.15.23);
4. Technical description of additional energy management functionality (see Pt 16, Ch 2, 23.16 Hybrid electrical power system components - Energy management 23.16.8);
5. Validation, verification and results of energy flow simulation (see Pt 16, Ch 2, 23.23 Power system development and integration - Energy flows 23.23.3);
6. Validation, verification and results of power system simulation (see Pt 16, Ch 2, 23.24 Power system development and integration - Power system analysis 23.24.4);
7. Risk assessment study when required (see Pt 16, Ch 2, 23.26 Power system development and integration - Risk assessment); and
8. Evidence of ship-specific Operator training verification (see Pt 16, Ch 2, 23.29 Power system development and integration - Operator training 23.29.2).

1.3.1 The documentation and particulars in Pt 16, Ch 2, 1.3 Documentation required for supporting evidence 1.3.2 to Pt 16, Ch 2, 1.3 Documentation required for supporting evidence 1.3.7 are to be submitted as supporting evidence.

1.3.2 In order to establish compliance with Pt 16, Ch 2, 1.11 Location and construction 1.11.2 and Pt 16, Ch 2, 5.1 Systems of supply and distribution 5.1.3 to Pt 16, Ch 2, 5.1 Systems of supply and distribution 5.1.5, a general arrangement plan of the craft showing the location of major items of electrical equipment, for example:

• main and emergency generators;
• transitional source of supply (where fitted);
• switchboards;
• section boards and distribution boards supplying essential and emergency services;
• emergency batteries;
• motors for emergency services; and
• cable routes between these items of equipment.

1.3.3 Arrangement plans of main and emergency switchboards, and section boards, and documentation that demonstrates that creepage and clearance distances are in accordance with Pt 16, Ch 2, 7.5 Creepage and clearance distances. The form factor of internal separation of low voltage switchgear and controlgear assemblies is to be in accordance with IEC 61439-2: Low-voltage switchgear and controlgear assemblies — Part 2: Power switchgear and controlgear assemblies, or an alternative acceptable and relevant National Standard. The form factor is to be stated, and the arrangement plans are to show how the forms have been achieved.

1.3.4 In order to establish compliance with the requirements of Pt 16, Ch 2, 1.7 Design and construction 1.7.3, when requested, evidence is to be submitted to demonstrate the suitability of electrical equipment for its intended purpose in the conditions in which it is expected to operate.

1.3.5 For non-metallic cable support systems or protective casings, test evidence, details of installation procedures and manufacturer’s recommendations that show compliance with Pt 16, Ch 2, 11.13 Non-metallic cable support systems, protective casings and fixings.

1.3.6 Details of, and arrangements in, the spaces in which the lighting is required to satisfy the requirements of Pt 16, Ch 2, 22 Ergonomic Lighting Design – ELD optional notation Ergonomic Lighting Design (EDL) optional notation.

1.3.7 Lithium battery systems. In addition to the plans and information required by Pt 16, Ch 2, 1.2 Documentation required for design review 1.2.13, the following information is also to be submitted:

1. Document outlining the operational limitations for the battery system.
2. Operation, maintenance and training manuals for the battery system are to be kept on board including:
   1. Manual that describes the standard operating, maintenance and emergency procedures for the system;
   2. Testing procedures including Annual Survey test requirements (see Table 2.21.2 Test requirements on lithium battery systems);
   3. Through-life management plan for the battery system, including disposal.

1.4.1 Electrical machinery and auxiliary services essential for the safety of the craft are to be installed in accordance with the relevant requirements of this Chapter, surveyed and have tests witnessed by the Surveyors.

1.4.2 The following equipment, where intended for use for essential and emergency services, is to be surveyed by the Surveyors during manufacture and testing:

• Converting equipment of 100 kW and over;
• Rotating machines of 100 kW and over;
• Switchboards and section boards;
• UPS units of 50 kVA and over; and
• Lithium Battery Systems of capacity 50 kWh and over including associated Battery Management Systems.

1.4.3 For electric propulsion systems, in addition to the equipment listed in Pt 16, Ch 2, 1.4 Surveys 1.4.2, the following equipment is to be surveyed by the Surveyors during manufacture and testing:

• exciters;
• filters;
• reactors;
• dynamic braking assemblies;
• pre-magnetisation transformers; and
• slip ring assemblies.

1.4.4 All other electrical equipment, not specifically referenced in Pt 16, Ch 2, 1.4 Surveys 1.4.2 and Pt 16, Ch 2, 1.4 Surveys 1.4.3, intended for use for essential or emergency services is to be supplied with a manufacturer's works test certificate showing compliance with the constructional standard(s) as referenced by the relevant requirements of this Chapter.

1.5.1 No addition, temporary or permanent, is to be made to the approved load of an existing installation until it has been ascertained that the current carrying capacity and the condition of the existing equipment including cables and switchgear are adequate for the increased load.

1.5.2 Plans are to be submitted for consideration, and the alterations or additions are to be carried out under the survey, and to the satisfaction of the Surveyors.

1.5.3 When it is proposed to replace permanently installed secondary valve-regulated sealed batteries with vented batteries, details are to be submitted for consideration to ensure continued safety in the presence of the products of electrolysis and evaporation being allowed to escape freely from the cells to the atmosphere. These details are to demonstrate that there will be adequate ventilation in accordance with Pt 16, Ch 2, 12.5 Thermal management and ventilation 12.5.9 and that the location and installation requirements of Pt 16, Ch 2, 12.3 Location and Pt 16, Ch 2, 12.4 Installation are complied with.

1.5.4 Proposed modifications to the electrical protection systems are to be developed in accordance with Pt 16, Ch 2, 6.1 General 6.1.4 and plans submitted are also to address the updating of approved version of the details required by Pt 16, Ch 2, 1.2 Documentation required for design review 1.2.5 and Pt 16, Ch 2, 1.2 Documentation required for design review 1.2.6.

1.5.5 Where it is intended to replace an existing incandescent lamp type navigation light with a light emitting diode type navigation light, details are to be submitted for consideration that demonstrate compliance with Pt 16, Ch 2, 15.3 Navigation lights. Light emitting diode type navigation light failure detection arrangements are to satisfy the requirements of Pt 16, Ch 2, 15.3 Navigation lights 15.3.5 and Pt 16, Ch 2, 15.3 Navigation lights 15.3.6.

1.6.1 Essential services are those necessary for the propulsion and safety of the craft, such as the following:

• air compressors for starting and manoeuvring essential mains and auxiliary machinery;
• air pumps;
• automatic sprinkler systems;
• ballast pumps;
• bilge pumps;
• circulating and cooling water pumps;
• communication systems;
• electric starting systems for starting and manoeuvring essential main and auxilliary machinery;
• fire detection and alarm systems;
• fire pumps;
• fuel valve cooling pumps;
• hydraulic pumps for controllable pitch propellers and those serving essential services here listed that would otherwise be directly electrically-driven;
• hydraulic pumps serving essential services here listed which would otherwise be directly electrically driven;
• lubricating oil pumps;
• lighting systems for those parts of the craft normally accessible to and used by personnel and passengers;
• navigational aids where required by Statutory Regulations;
• navigation lights and special purpose lights where required by Statutory regulations;
• fuel oil pumps and fuel oil burning units;
• pumps for fire-extinguishing systems;
• scavenge blowers;
• steering gear;
• Thrusters needed for the propulsion and safety of the ship to be considered as essential services;
• valves which are required to be remotely operated;
• ventilating fans for engine rooms;
• watertight doors, shell doors and other electrical operated closing appliances;
• windlasses;
• power sources and supply systems for supplying the above services.

1.6.2 Services such as the following are considered necessary for minimum comfortable conditions of habitability:

• cooking;
• heating;
• domestic refrigeration;
• mechanical ventilation;
• sanitary and fresh water.

1.6.3 Services such as the following, which are additional to those in Pt 16, Ch 2, 1.6 Definitions 1.6.1 and Pt 16, Ch 2, 1.6 Definitions 1.6.2, are considered necessary to maintain the craft in a normal seagoing operational and habitable condition:

• cargo handling and cargo care equipment;
• hotel services, other than those required for habitable conditions;
• thruster systems for manoeuvring.

1.6.4 A `high voltage' is a voltage exceeding 1000 V a.c. or 1500 V d.c. between conductors, see also Pt 16, Ch 2, 5.1 Systems of supply and distribution 5.1.2.

1.6.5 A `switchboard' is a switchgear and controlgear assembly for the control of power generated by a source of electrical power and its distribution to electrical consumers.

1.6.6 A `section board' is a switchgear and controlgear assembly for controlling the supply of electrical power from a switchboard and distributing it to other section boards, distribution boards or final sub-circuits.

1.6.7 A `distribution board' is an assembly of one or more protective devices arranged for the distribution of electrical power to final sub-circuits.

1.6.8 A `final sub-circuit' is that portion of a wiring system extending beyond the final overcurrent device of a board.

1.6.9 `Special Category spaces' are those enclosed spaces above or below the bulkhead deck intended for the carriage of motor vehicles with fuel, for their own propulsion, in their tanks, into and from which such vehicles can be driven, and to which passengers have access.

1.6.10 'Machinery spaces of Category A' are those spaces and trunks to such spaces which contain:

1. internal combustion machinery used for main propulsion; or

2. internal combustion machinery used for purposes other than main propulsion where such machinery has in the aggregate a total power output of not less than 375 kW; or

3. any oil-fired boiler or fuel oil unit.

1.6.11 `Dead craft condition' means that the entire machinery installation, including the power supply, is out of operation and that the auxiliary services for bringing the main propulsion systems into operation (e.g. compressed air, starting current from batteries, etc.) and for the restoration of the main power supply are not available. Means are to be available at all times to start the emergency generator, see Pt 10, Ch 1, 9.5 Starting of the emergency source of power.

1.6.12 Protected space is a machinery space where a fixed water-based local application fire-fighting system is installed.

1.6.13 Protected areas are areas within a protected space which is required to be protected by a fixed water-based local application fire-fighting system.

1.6.14 Adjacent areas are areas, other than protected areas, exposed to direct spray or other areas where water may extend when a fixed water-based local application fire-fighting system is activated.

1.6.15 An ‘electric arc’ is an electrical discharge or a short-circuit through ionised air caused by isolation or insulation integrity failure.

1.6.16 ‘Incident energy’ is the amount of energy impressed on a surface, a certain distance from the source, generated during an electric arc event.

1.6.17 A ‘secondary lithium cell’ is a cell where electrical energy is derived from the insertion/extraction reactions of lithium ions or oxidation/reduction of lithium between the negative electrode and the positive electrode. These may be combined in ‘cell blocks’ consisting of a group of cells connected together in a parallel configuration.

1.6.18 A ‘battery module’ is an energy storage device comprising one or more electrically connected cells or cell blocks. The battery module can include protective and monitoring devices.

1.6.19 A ‘battery pack’ is an energy storage device comprising one or more electrically connected cells, cell blocks or modules. The battery pack can include protective devices and control and monitoring systems which communicate with the battery management system.

1.6.20 A ‘battery management system (BMS)’ is an electronic system which monitors and manages the state of a cell, battery module or battery pack in order to maintain the battery system in a safe operating state and protect against overcharging, overcurrent and overheating and communicates with an external charge/discharger controller.

1.6.21 A ‘lithium battery system’ is a system comprising one or more lithium battery modules or packs incorporated in a fixed installation together with means of isolation, a cooling system (if provided) and has an associated BMS.

1.6.22 ‘State of charge (SOC)’ is the available capacity in a battery expressed as a percentage of rated capacity.

1.6.23 ‘State of health (SOH)’ reflects the general condition of a battery expressed as a percentage of its ability to deliver the specified performance compared with that of a new battery.

1.6.24 ‘Battery space’ is the space or compartment in which a battery is installed.

1.7.1 Equipment for services essential for the safety of the craft are to be constructed in accordance with the relevant requirements of this Chapter.

1.7.2 The design and installation of other equipment is to be such that risk of fire due to its failure is minimised. It is to, as a minimum, comply with a National or International Standard revised where necessary for ambient conditions.

1.7.3 Electrical equipment is to be suitable for its intended purpose and accordingly, whenever practicable to be selected from the List of Type Approved Products published by Clasifications Register's (hereinafter referred to as 'LR'). A copy of the Procedure for LR Type Approval System will be supplied on application.

1.7.5 For areas susceptible to deluge or submersion, cable entries are to prevent water ingress. In general, cable entries are to be in accordance with IEC 60092-101: Electrical Installations in Ships – Part 101: Definitions and General Requirements.

1.8.1 All electrical equipment supplied from the main and emergency sources of electrical power and electrical equipment for essential and emergency services supplied from d.c. sources of electrical power is to be so designed and manufactured that it is capable of operating satisfactorily under normally occurring variations of voltage and frequency.

1.8.2 Unless specified otherwise, a.c. electrical equipment is to operate satisfactorily with the following simultaneous variations, from their nominal value, when measured at the consumer input terminals. Alarms are to be provided for High and Low Voltage and Low Frequency.

1. Voltage:

   • permanent variations +6 per cent, -10 per cent
   • transient variations due to step changes in load ±20 per cent
   • recovery time 1,5 seconds

2. Frequency:

   • permanent variations ±5 per cent
   • transient variations due to step changes in load ±10 per cent
   • recovery time 5 seconds

A maximum rate of change of frequency not exceeding ±1,5 Hz per second during cyclic frequency fluctuations.

1.8.3 Unless specified otherwise, the total harmonic distortion (THD) of the voltage waveform at any a.c. switchboard or section-board is not to exceed 8 per cent of the fundamental for all frequencies up to 50 times the supply frequency and no voltage at a frequency above 25 times supply frequency is to exceed 1,5 per cent of the fundamental of the supply voltage. THD is the ratio of the rms value of the harmonic content to the rms value of the fundamental, expressed in per cent and may be calculated using the expression:

1.8.4 Where a higher value of THD is specified, all installed equipment and systems are to be designed for the higher specified limit. This relaxation on the limit is to be documented in the harmonic distortion calculation report.

1.8.5 Unless specified otherwise, d.c. electrical equipment is to operate satisfactorily with the following simultaneous variations, from their nominal value, when measured at the consumer input terminals:

1. When supplied by d.c. generator(s) or a rectified a.c. supply:

   Voltage tolerance (continuous) ±10 per cent

   Voltage cyclic variation deviation 5 per cent

   Voltage ripple 10 per cent

   (a.c. rms over steady state d.c. voltage);

2. When supplied by batteries:

   1. Equipment connected to the batteries during charging:

      Voltage tolerance +30 per cent, -25 per cent;

   2. Equipment not connected to batteries during charging:

      Voltage tolerance +20 per cent, -25 per cent

Different voltage variations as determined by the charging/discharging characteristics, including ripple voltage from the charging device, may be considered. When battery chargers/battery combinations are used as d.c. power supply systems adequate measures are to be taken to keep the voltage within the specified limits during charging, boost charging and discharging of the battery.

1.9.1 The rating for classification purposes of essential electrical equipment intended for installation in craft to be classed for unrestricted (geographical) service is to be based on an engine room ambient temperature of 45^oC, and a sea-water temperature at the inlet of 32^oC. The equipment manufacturer is not expected to provide simulated ambient reference conditions at a test bed.

1.9.2 In the case of craft to be classed for restricted service, the rating is to be suitable for the ambient conditions associated with the geographical limits of the restricted service which are part of the class notation.

1.9.3 Main and essential auxiliary machinery and equipment are to operate satisfactorily under the conditions shown in Pt 9, Ch 1, 4.5 Ambient operating conditions. Electrical equipment satisfying alternative ambient operating condition requirements for installation on ships contained in an acceptable and relevant National or International Standard may be considered to satisfy this requirement.

1.9.4 Where electrical equipment is installed within environmentally controlled spaces, the ambient temperature for which the equipment is suitable for operation at its rated capacity may be reduced to a value not less than 35°C provided:

• the equipment is not for use for emergency services and is located outside of machinery space(s);
• temperature control is achieved by at least two cooling units so arranged that, in the event of loss of one cooling unit, for any reason, the remaining unit(s) will be capable of satisfactorily maintaining the design temperature;
• the equipment is able to be initially set to work safely within a 45°C ambient temperature until such a time that the lesser ambient temperature may be achieved; the cooling equipment is to be rated for an ambient temperature of not less than 45°C; and
• alarms are provided, at a continually attended control station, to indicate any malfunction of the cooling units.

See also Pt 16, Ch 1, 1.3 Control, alarm and safety equipment 1.3.3.

1.9.5 Where equipment is to comply with Pt 16, Ch 2, 1.9 Ambient reference and operating conditions 1.9.4, it is to be ensured that electrical cables for their entire length are adequately rated for the maximum ambient temperature to which they are exposed along their length.

1.9.6 Equipment used for cooling and maintaining the lesser ambient temperature in accordance with Pt 16, Ch 2, 1.9 Ambient reference and operating conditions 1.9.4 are considered essential services and are to satisfy the requirements of Pt 16, Ch 2, 5.2 Essential services.

1.10.1 Emergency and essential electrical equipment is to operate satisfactorily under the conditions as shown in Table 1.4.1 Inclinations.

1.11.1 All electrical equipment is to be constructed or selected, and installed such that:

1. live parts cannot be inadvertently touched, unless they are supplied at the safety voltage specified in Pt 16, Ch 2, 1.12 Earthing of non-current carrying parts 1.12.2.(h);

2. it does not cause injury when handled or touched in the normal manner; and

3. it is unaffected by any water, steam or oil and oil vapour to which it is likely to be exposed.

Electrical equipment having, as a minimum, the degrees of protection as specified in IEC 60092-201: Electrical installations in ships – Part 201: System design – General for the relevant location will satisfy these requirements. For high voltage electrical equipment, the degrees of protection as specified in IEC 60092-503 Electrical installations in ships – Part 503: Special features – AC supply systems with voltages in the range of above 1kV up to and including 36kV for the relevant location will satisfy these requirements.

1.11.2 Switchboards, section boards and distribution boards supplying essential and emergency services, as well as cables from the respective generators to and between these boards, are to be arranged to avoid areas of high fire risk and elevated temperatures, for example, in close proximity to incinerators and boilers.

1.11.3 Electrical equipment, as far as is practicable, is to be located:

1. such that it is accessible for the purpose of maintenance and survey;

2. clear of flammable material;

3. in spaces adequately ventilated to remove the waste heat liberated by the equipment under full load conditions, at the ambient conditions specified in Pt 16, Ch 2, 1.9 Ambient reference and operating conditions;

4. where flammable gases cannot accumulate. If this is not practicable, electrical equipment is to be of the appropriate 'safe-type', see Pt 16, Ch 2, 14 Electrical equipment for use in explosive atmospheres;

5. where it is not exposed to the risk of mechanical injury or damage from water, steam or oil.

1.11.4 Equipment design and the choice of materials are to reduce the likelihood of fire, ensuring that:

1. where the electrical energised part can cause ignition and fire, it is contained within the bounds of the enclosure of the electrotechnical product;

2. the design, material(s) and construction of the enclosure minimises, as far as is practicable, any internal ignition causing ignition of adjacent materials; and

3. where surfaces of the electrotechnical products can be exposed to external fire, they do not, as far as practicable, contribute to the fire growth.

1.11.5 Insulating materials and insulated windings are to be resistant to tracking, moisture, sea air, oil and oil vapour unless special precautions are taken to protect them.

1.11.6 The minimum creepage and clearance distances provided for electrical connections, terminals and similar bare live parts are to be in accordance with a relevant International or National Standard for the equipment or apparatus concerned. In cases where the rated voltage is outside that given in the Standard or where no Standard is available, the minimum creepage and clearance distances provided are to be in accordance with Pt 16, Ch 2, 7.5 Creepage and clearance distances. Details of alternatives proposals including supporting design rationale and demonstration may be submitted for consideration.

1.11.7 Studs, screw-type or spring-type clamp terminations, satisfactory for the normal operating currents and voltages, are to be provided in electrical equipment for the connection of external cable, or bus-bar conductors, as appropriate, see also Pt 16, Ch 2, 11.15 Electric cable ends. There is to be adequate space and access for the terminations.

1.11.8 The design of equipment is to enable ease of access to all parts requiring inspection or replacement in service.

1.11.9 Equipment is not to remain alive through the control circuits and/or pilot lamps when switched off by the control switch. This does not apply to synchronising switches and/or plugs.

1.11.10 The operation of all electrical equipment and the lubrication arrangements are to be efficient under such conditions of vibration and shock as arise in normal practice.

1.11.11 All nuts, screws and clamping devices used in connection with current-carrying, supporting and working parts are to be provided with means to ensure that they cannot work loose by vibration and shock as arise in normal practice.

1.11.12 To allow ease of access, connectors are to be spaced far enough apart to permit connection and disconnection. At test points, adequate clearance is to be provided between connection points and controls to provide access for testing.

1.11.13 Conductors and equipment are to be placed at such a distance from the magnetic compasses, or are to be so disposed, that the interfering magnetic field is negligible when circuits are switched on and off.

1.11.14 Where electrical power is used for propulsion, the equipment is to be so arranged that it will operate satisfactorily in the event of partial flooding by bilge water above the tank top up to the bottom floor plate level, under the normal angles of inclination given in Pt 16, Ch 2, 1.10 Inclination of craft for essential electrical equipment, see Pt 15, Ch 2 Ship Piping Systems.

1.12.1 Except where exempted by Pt 16, Ch 2, 1.12 Earthing of non-current carrying parts 1.12.2, all non-current carrying exposed metal parts of electrical equipment and cables are to be earthed for personnel protection against electric shock. Bonding of non-current carrying exposed metal parts is to give a substantially equal potential and a sufficiently low earth fault loop impedance to ensure correct operation of protective devices.

1.12.2 The following parts may be exempted from the requirements of Pt 16, Ch 2, 1.12 Earthing of non-current carrying parts 1.12.1:

1. lamp-caps, where suitably shrouded;

2. shades, reflectors and guards supported on lampholders or light fittings constructed of, or shrouded in, non-conducting material;

3. metal parts on, or screws in or through, non-conducting materials, which are separated by such material from current-carrying parts and from earthed non-current carrying parts in such a way that in normal use they cannot become live or come into contact with earthed parts;

4. apparatus which is constructed in accordance with the principle of double insulation;

5. bearing housings which are insulated in order to prevent circulation of current in the bearings;

6. clips for fluorescent lamps;

7. cable clips and short lengths of pipes for cable protection;

8. apparatus supplied at a safety voltage not exceeding 50 V d.c. or 50 V a.c., between conductors, or between any conductor and earth in a circuit isolated from the supply. Autotransformers are not to be used for the purpose of achieving the alternating current voltage;

9. apparatus or parts of apparatus which although not shrouded in insulating material is nevertheless otherwise so guarded that it cannot be touched and cannot come in contact with exposed metal.

1.12.3 Where extraneous-conductive parts (i.e. parts not forming part of the electrical installation and liable to introduce an electric potential) are not bonded by separate earthing conductors, details are to be submitted that demonstrate that a permanent, metal-to-metal connection of negligible impedance, which will not degrade due to corrosion or vibration, will be achieved.

1.12.4 Armouring, braiding and other metal coverings of cables are to be effectively earthed. Where the armouring, braiding and other metal coverings are earthed at one end only, they are to be adequately protected and insulated at the unearthed end with the insulation being suitable for the maximum voltage that may be induced. See Pt 16, Ch 2, 14.1 General for earthing of cables in hazardous zones or spaces.

1.12.5 The electrical continuity of all metal coverings of cables throughout the length of the cable, particularly at joints and tappings, is to be ensured.

1.12.6 Metal parts of portable appliances, other than current-carrying parts and parts exempted by Pt 16, Ch 2, 1.12 Earthing of non-current carrying parts 1.12.2 are to be earthed by means of an earth-continuity conductor in the flexible cable or cord through the associated plug and socket-outlet.

1.12.7 Earthing conductors are to be of copper or other corrosion-resistant material and be securely installed and protected where necessary against damage and also, where necessary, against electrolytic corrosion. Connections are to be so secured that they cannot work loose under vibration.

1.12.8 The nominal cross-section areas of copper earthing conductors are, in general to be equal to the cross-section of the current-carrying conductor up to 16 mm². Above this figure they are to be equal to at least half the cross-section of the current-carrying conductor with a minimum of 16 mm². Every other earthing conductor is to have a conductance not less than that specified for an equivalent copper earthing conductor.

1.12.9 The connection of the earthing conductor to the hull of the craft is to be made in an accessible position, and is to be secured by a screw or stud of a diameter appropriate for the size of earthing conductor, but not less than 6 mm which is to be used for this purpose only. Bright metallic surfaces at the contact areas are to be ensured immediately before the nut or screw is tightened and, where necessary, the joint is to be protected against electrolytic corrosion. The connection is to remain unpainted.

1.13.1 In non-metallic craft, all metallic parts of the craft are to be electrically bonded together, as far as possible, in consideration of galvanic corrosion between dissimilar metals, to ensure an earth return path and to connect the craft to the water when water-borne. This does not apply to isolated components which cannot become live, nor require control of static electricity.

1.13.2 Bonding straps for the control of static electricity are required for piping systems, including pressure refuelling points, which are not electrically continuous throughout their length and for flammable products, which are not permanently connected to the hull of the craft either directly or via their bolted or welded supports and where the resistance between them and the hull exceeds 1MΩ.

1.13.3 Where bonding straps are required for the control of static electricity, they are to be robust, that is, having a cross-sectional area of at least 10 mm², and are to comply with Pt 16, Ch 2, 1.12 Earthing of non-current carrying parts 1.12.7 and Pt 16, Ch 2, 1.12 Earthing of non-current carrying parts 1.12.9.

1.14.1 Labels, signs and notices required by this Chapter are to be positioned in clearly visible locations which will not be obscured.

1.14.2 Labels, signs and notices are to be easy to read under the expected operating conditions. Character height in accordance with Table 2.1.1 Character height and viewing distance will be considered to satisfy this requirement.

1.14.3 Controls, indicators and displays required by this Chapter are to be labelled to indicate their function. Labels are to be positioned in a manner that associates the label with the item being labelled.

1.14.4 Labels, signs and notices are to use short, clear messages. In general, warning signs and notices are to comprise:

• a word signalling the gravity of the risk (e.g. Danger, Warning or Caution);
• a statement of the nature and/or consequence of the hazard; and
• wherever practical, an instruction giving appropriate behaviour to avoid the hazard.

1.14.5 Electrical equipment that presents an electric arc-flash hazard to personnel is to be clearly marked, see Pt 16, Ch 2, 8.1 General 8.1.1.

1.15.1 Where alarms are required by this Chapter they are to be arranged in accordance with Pt 16, Ch 1, 2.3 Alarm systems. Sound signal equipment, fire and general alarm bells are not required to be supplemented by visual indications, except in areas having high levels of background noise, such as machinery spaces.

1.15.2 The alarms in this Chapter are additional to those required by Pt 16, Ch 1 Control Engineering Systems. They may however form part of the alarm system that is required by Pt 16, Ch 1 Control Engineering Systems.

1.15.3 Cables for emergency alarms and their power sources are to be in accordance with Pt 16, Ch 2, 1.16 Operation under fire conditions.

1.15.4 Electrical equipment and cables for emergency alarms are to be so arranged that the loss of alarms in any one area due to localised fire, collision, flooding or similar damage is minimised, see Pt 16, Ch 2, 1.16 Operation under fire conditions.

1.16.1 As a minimum, the following emergency services and their emergency power supplies, are required to be capable of being operated under fire conditions:

• Control and power systems to power-operated fire doors and status indication for all fire doors.
• Control and power systems to power-operated watertight doors and their status indication.
• Emergency lighting.
• Fire and general emergency alarms.
• Fire detection systems.
• Fire-extinguishing systems and fire-extinguishing media release alarms.
• Fire safety stops, see also Pt 16, Ch 2, 17.6 Fire safety stops.
• Low location lighting, see also Pt 16, Ch 2, 18.4 Escape route or low location lighting (LLL) 18.4.3.
• Public address systems.
• Emergency fire pump.

1.16.2 Where cables for the emergency services listed in Pt 16, Ch 2, 1.16 Operation under fire conditions 1.16.1 pass through high fire risk areas, or main vertical or horizontal fire zones other than those which they serve, they are to be so arranged that a fire in any of these areas or zones does not affect the operation of the emergency service in any other area or zone. This may be achieved either by:

• cables being of a fire-resistant type complying with Pt 16, Ch 2, 11.5 Construction 11.5.3, and at least extending from the main control/monitoring panel to the nearest local distribution panel serving the relevant area or zone; or
• there being at least two-loops/radial distributions run as widely apart as is practicable and so arranged that in the event of damage by fire at least one of the loops/radial distributions remains operational.

1.16.3 Where the cables for the power supplies for the emergency services listed in Pt 16, Ch 2, 1.16 Operation under fire conditions 1.16.1 pass through high fire risk areas, or main vertical or horizontal fire zones other than those which they serve, they are to be of a fire-resistant type complying with Pt 16, Ch 2, 11.5 Construction 11.5.3, extending at least to the local distribution panel serving the relevant area or zone.

1.16.4 Fire-resistant electrical cables for the emergency services listed in Pt 16, Ch 2, 1.16 Operation under fire conditions 1.16.1, including their power supplies, are to be run as directly as is practicable, having regard to any special installation requirements, for example those concerning minimum bend radii.

1.16.5 In addition to Pt 16, Ch 2, 1.11 Location and construction 1.11.4, materials used for electrical equipment, cables and accessories within passenger accommodation areas are not to be capable of producing excessive quantities of smoke and toxic products.

1.17.1 In order to minimise the risks of damage to the craft and its electrical installation due to lightning, crafts having non-metallic masts or topmasts are to be fitted with lightning conductors in accordance with the applicable requirements of IEC 60092-401: Electrical installations in ships – Part 401: Installation and test of completed installation or an alternative and relevant National Standard.

1.17.2 In addition to the primary protection requirements in Pt 16, Ch 2, 1.17 Lightning protection 1.17.1, precautions are to be taken to protect essential electronic equipment that may be susceptible to damage from voltage pulses attributable to the secondary effects of lightning. This may be achieved by suitable design and/or the use of additional protective devices, such as surge arrestors. Resultant induced voltages may be further reduced by the use of earthed metallic screened cables.

1.18.1 Where programmable electronic systems are implemented and used to control the electrical installation, or to provide safety functions in accordance with the requirements of this Chapter (e.g. electric propulsion, circuit-breaker settings, switchgear and controlgear controllers, etc.), the arrangements are to satisfy the applicable requirements of Pt 16, Ch 1, 2.10 Programmable electronic systems – General requirements to Pt 16, Ch 1, 2.14 Programmable electronic systems - Additional requirements for integrated systems.

1.18.2 Where Pt 16, Ch 2, 1.18 Programmable electronic systems 1.18.1 applies, proposed modifications to software and acceptance testing and trials are to be in accordance with Pt 16, Ch 1, 1.4 Alterations and additions and Pt 16, Ch 2, 7 Switchgear and controlgear assemblies as applicable.