Section 1 Testing and trials
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Naval Ships, January 2023 - Volume 2 Machinery and Engineering Systems - Part 9 Electrotechnical Systems - Chapter 12 Testing and Trials - Section 1 Testing and trials

Section 1 Testing and trials

1.1 Testing

1.1.1 Tests in accordance with Vol 2, Pt 9, Ch 12, 1.1 Testing 1.1.2 are to be satisfactorily carried out on all electrical equipment, complete or in sections, at the manufacturer’s premises and a test report issued by the manufacturer.

1.1.2 A high voltage at any frequency between 25 and 100 Hz is to be applied between:

  1. all current carrying parts connected together and earth;

  2. all current carrying parts of opposite polarity or phase.

For rotating machines the value of test voltage is to be 1000 V plus 2 x rated voltage with a minimum of 2000 V, and for other electrical equipment, it is to be in accordance with Table 12.1.1 Test voltage. Items of equipment included in the assembly for which a test voltage lower than the above is specified may be disconnected during the test and tested separately at the appropriate lower test voltage. The test is to be commenced at a voltage of about one-third the test voltage and is to be increased to full value as rapidly as is consistent with its value being indicated by the measuring instrument. The full test voltage is then to be maintained for 1 minute, and then reduced to one-third full value before switching off. The assembly is considered to have passed the test if no disruptive discharge occurs.

Table 12.1.1 Test voltage

Rated voltage, Un
Un V
Test voltage a.c. (r.m.s.), V
Un ≤ 60 500
60 < Un ≤ 1000 2Un + 1000
1000 < Un ≤ 2500 6500
2500 < Un ≤ 3500 10000
3500 < Un ≤ 7200 20000
7200 < Un ≤ 12000 28000
12000 < Un ≤ 15000 38000
15000 < Un ≤ 22000 50000
22000 < Un ≤ 33000 70000
33000 < Un ≤ 35000 80000

1.1.3 When it is desired to make additional high voltage tests on equipment which has already passed its tests, the voltage of such additional tests is to be 80 per cent of the test voltage the equipment has already passed.

1.1.4 Immediately after the high voltage test, the insulation resistance is to be measured using a direct current insulation tester, between:

  1. all current carrying parts connected together and earth;

  2. all current carrying parts of different polarity or phase.

The minimum values of test voltage and insulation resistance are given in Table 12.1.2 Test voltage and minimum insulation.

Table 12.1.2 Test voltage and minimum insulation

Rated voltage
Un V
Minimum voltage of the tests, V Minimum insulation resistance, MΩ
Un ≤ 250 2Un 1
250 < Un ≤ 1000 500 1
1000 < Un ≤ 7200 1000

7200 < Un ≤ 15000 5000

Un > 15000 5000

1.1.5 Tests in accordance with the standard with which the equipment complies may be accepted as an alternative to the above.

1.1.6 Tests at the manufacturers’ works and trials after installation on board are to include such tests necessary to demonstrate, to the Surveyor’s satisfaction, the suitability and safety of the lithium battery system for its intended duty and location. As a minimum, the tests listed in Table 12.1.3 Test/Trials requirements on lithium battery systems are required.

Table 12.1.3 Test/Trials requirements on lithium battery systems

Item Tests Trials
Performance test X X
Sensor failures test X
State of Charge (SOC) indication test X X
State of Health (SOH) indication test X X
High voltage test X
Insulation resistance test X
Alarms and safeguards required by Table 2.7.1 Lithium battery system: alarms and safeguards X X
Communication failure between Battery Management System (BMS) and external charge control system test X X
Verification of thermal management at maximum achievable load under service conditions during trials   X
Tests of the safety functions in the battery compartment, i.e. fire detection and extinguishing, gas detection, off-gas exhaust/extraction, ventilation, etc., as applicable to the installation   X

1.2 Trials

1.2.1 Before a new installation, or any alteration or addition to an existing installation, is put into service the applicable trials in Vol 2, Pt 9, Ch 12, 1.2 Trials 1.2.2 are to be carried out. These trials are in addition to any acceptance tests which may have been carried out at the manufacturer’s works and are to be to the Surveyor’s satisfaction. A report having the results of measurements taken during the trials is to be submitted for record purposes.

1.2.2 Means are to be provided to facilitate testing during normal machinery operation, e.g. by the provision of three-way test valves or equivalent.

1.2.3 Acceptance tests and trials for Programmable Electronic Systems are to include verification of software lifecycle activities appropriate to the stage in the system's lifecycle at the time of system examination. The documentation required by Vol 2, Pt 9, Ch 1, 1.4 Documentation required for design review 1.4.8 is to be in accordance with the current configuration and the testing and trials are to address software modifications to the Surveyor’s satisfaction.

1.2.4 Wireless data communication links are to be operational and tested during trials. Tests are to demonstrate that radio-frequency transmission does not interfere with the operation of equipment required by this Chapter or other Sections of the Rules and does not itself malfunction as a result of electromagnetic interference during expected operating conditions. Reversionary modes are to be activated to demonstrate continued safe and effective operation in the event of fault conditions.

1.2.5 The insulation resistance is to be measured of all electrical power circuits and electrical equipment, using a direct current insulation tester, between:

  1. all current carrying parts connected together and earth and, so far as is reasonably practicable;

  2. all current carrying parts of different polarity or phase.

The minimum values of test voltage and insulation resistance are given in Table 12.1.2 Test voltage and minimum insulation The installation may be subdivided and appliances may be disconnected if initial tests produce results less than these figures.

1.2.6 Tests are to be made to verify the effectiveness of:

  1. earth continuity conductor;

  2. the earthing of non-current carrying exposed metal parts of electrical equipment and cables not exempted by Vol 2, Pt 9, Ch 1, 2.4 Earthing and bonding 2.4.2;

  3. bonding for the control of static electricity.

1.2.7 It is to be demonstrated that the Rules have been complied with in respect of:

  1. satisfactory performance of each power source supporting Mobility or Ship type systems, including its auxiliary services, throughout a run at full rated load;

  2. temperature of joint, connections, circuit-breakers and fuses;

  3. the operation of engine governors, synchronising devices, overspeed trips, reverse-current, reverse-power and over-current trips and other safety devices;

  4. voltage regulation of every generator when full rated load is suddenly thrown off and when starting the largest motor connected to the system;

  5. voltage drop at the worst case condition;

  6. harmonic distortion of the voltage waveform. Where harmonic filters are installed, the calculation results provided by the system integrator are to be verified by the Surveyor. Simulations in trials of harmonic filter failure that would result in THD levels calculated to be higher than the acceptable limit are to be avoided. See Vol 2, Pt 9, Ch 3, 4.11 Harmonic filtering;

  7. satisfactory parallel operation, and kW and KVA load sharing of all generators capable of being operated in parallel at all loads up to normal working load;

  8. all Mobility systems, Ship Type systems, and other important equipment are to be operated under service conditions, though not necessarily at full load or simultaneously, for a sufficient length of time to demonstrate that they are satisfactory;

  9. propulsion equipment is to be tested under working conditions and operated in the presence of the Surveyors and to their satisfaction. The equipment is to have sufficient power for going astern to secure proper control of the ship in all normal circumstances. The ability of the machinery to reverse the direction of thrust of the propeller in sufficient time, under normal manoeuvring conditions, and so bring the ship to rest from maximum ahead service speed, is to be demonstrated at the sea trial, see also Vol 2, Pt 1, Ch 3, 17.3 Performance testing requirements for naval vessels 17.3.9;

  10. the operation of the propulsion system with the harmonic filter removed from circuit is to be verified in accordance with the design intent, see Vol 2, Pt 4, Ch 5, 4.5 Harmonic filtering for propulsion 4.5.2; any operational and functional limitations are to be documented and details retained on board;
  11. operation of power management for electric propulsion; and

  12. satisfactory performance of each Mobility or Ship Type system energy storage arrangement, including its auxiliary services, throughout a run at full-rated charging capacity.

1.2.8 Measurements are to be taken as part of the trials specified in Vol 2, Pt 9, Ch 12, 1.2 Trials 1.2.7.(c), Vol 2, Pt 9, Ch 12, 1.2 Trials 1.2.7.(d), Vol 2, Pt 9, Ch 12, 1.2 Trials 1.2.7.(e) and Vol 2, Pt 9, Ch 12, 1.2 Trials 1.2.7.(c) to verify that the installation will provide a quality of power supply in accordance with the values listed in Vol 2, Pt 9, Ch 1, 2.1 Quality of power supplies (QPS).

1.2.9 In addition to Vol 2, Pt 9, Ch 12, 1.2 Trials 1.2.5, unless it has been satisfactorily shown by the design verification and validation process required by Vol 2, Pt 9, Ch 1, 3.2 General requirements 3.2.4, that the power supply quality complies with the requirements of the specified standard, then compliance is to be demonstrated by measurements taken at representative ship operating loads, as defined by the Naval Administration, see Vol 2, Pt 9, Ch 1, 3.1 General 3.1.1.

1.2.10 It is to be demonstrated by practical tests that the Rules have been complied with in respect of fire, crew emergency and ship safety systems.

1.2.11 On completion of the general emergency alarm system and the crew and embarked personnel address system tests, the Surveyor is to be provided with two copies of the test schedule, detailing the measured sound pressure levels. Such schedules are to be signed by the Surveyor and the Builder.

1.3 High voltage cables

1.3.1 Before a new high voltage cable installation, or an addition to an existing installation, is put into service, a voltage withstand test is to be satisfactorily carried out on each completed cable and its accessories. The test is to be carried out after the insulation resistance test required by Vol 2, Pt 9, Ch 12, 1.2 Trials 1.2.2 and may use either an a.c. voltage at power frequency or a d.c. voltage.

1.3.2 When an a.c. voltage withstand test is carried out, the voltage is to be not less than the normal operating voltage of the cable and it is to be maintained for a minimum of 24 hours.

1.3.3 When a d.c. voltage withstand test is carried out, the voltage is to be not less than:

  1. 1,6 (2,5U o + 2 kV) for cables of rated voltages (U o) up to and including 3,6 kV; or

  2. 4,2U o for higher rated voltages where U o is the rated power frequency voltage between conductor and earth or metallic screen, for which the cable is designed. The test voltage is to be maintained for a minimum of 15 minutes. After completion of the test the conductors are to be connected to earth for a sufficient period in order to remove any trapped electric charge. An insulation resistance test in accordance with Vol 2, Pt 9, Ch 12, 1.2 Trials 1.2.2 is then to be repeated.

1.4 On-line partial discharge testing of high voltage rotating machines for ship type and mobility systems

1.4.1 Where on-line partial discharge monitoring equipment is installed for the monitoring of high voltage rotating machines used to provide ship type and mobility systems, the method used is to be appropriate for the design and application of the rotating machine, and conducted and recorded in accordance with:

  1. PD IEC/TS 60034-27-2:2012, Rotating electrical machines Part 27-2: On-line partial discharge measurements on the stator winding insulation of rotating electrical machines;
  2. DD IEC/TS 61934:2011, Electrical insulating materials and systems – Electrical measurement of partial discharges (PD) under short rise time and repetitive voltage impulses; or
  3. an alternative International or National Standard acceptable to LR.

1.4.2 The partial discharge measurement method used is to be acceptable to the rotating machine manufacturer. Particular attention is to be given to ensuring that:

  • the test voltage and frequency (i.e. a.c., or ultra-low frequency and voltage level), and method selected are to be compatible with the insulation systems; and
  • the tests do not over stress or cause accelerated ageing of the insulation system.

1.4.3 The test reports required by Vol 2, Pt 9, Ch 12, 1.4 On-line partial discharge testing of high voltage rotating machines for ship type and mobility systems 1.4.1 are to:

  • record the method and equipment used in sufficient detail to ensure the tests can be repeated consistently throughout the service life of the rotating machine; and
  • include, but are not limited to, the details recommended by the test standard to be applied.

1.4.4 Where partial discharge monitoring equipment has been installed in accordance with Vol 2, Pt 9, Ch 12, 1.4 On-line partial discharge testing of high voltage rotating machines for ship type and mobility systems 1.4.1 to enable through-life trend analysis:

  1. measurements are to be recorded at harbour acceptance trials or sea trials to baseline the partial discharge characteristics of the rotating machine, and then repeated annually; and
  2. a copy of the test reports and data is to be retained on board and made available to the Surveyor on request.

1.5 Optical Fibre Communications Systems

1.5.1 The attenuation loss of single mode optical fibre is to be tested prior to installation in accordance with IEC 61280: Fibre-optic communication subsystem test procedures Part 4-2: Installed cable plant – Single-mode attenuation and optical return loss measurement. The test is to be recorded in accordance with the standard. The documentation is to be retained on board and made available to the Surveyor on request. Acceptance of alternative standards will be subject to consideration by LR.

1.5.2 The attenuation loss of multimode optical fibre is to be tested prior to installation in accordance with IEC 61280: Fibre optic communication subsystem test procedures – Part 4-1: Installed cable plant – Multimode attenuation measurement. The test is to be recorded in accordance with the standard. The documentation is to be retained on board and made available to the Surveyor on request. Acceptance of alternative standards will be subject to consideration by LR.

1.5.3 The tests required by Vol 2, Pt 9, Ch 12, 1.5 Optical Fibre Communications Systems 1.5.1 and Vol 2, Pt 9, Ch 12, 1.5 Optical Fibre Communications Systems 1.5.2 are to be repeated after installation using the same method as used for the pre-installation test. The test is to be recorded in accordance with the standard; the documentation is to be retained on board and made available to the Surveyor on request. Acceptance of alternative standards will be subject to consideration by LR.

1.5.4 The results of the testing required by Vol 2, Pt 9, Ch 12, 1.5 Optical Fibre Communications Systems 1.5.3 are to be validated against the communication system design specification to ensure that adequate optical power will be transmitted for correct system operation (see Vol 2, Pt 9, Ch 1, 1.5 Documentation required for supporting evidence 1.5.8).

1.6 Hazardous areas

1.6.1 All electric equipment located in hazardous areas is to be examined to ensure that it is of a type permitted by the Rules, has been installed in compliance with its certification, and that the integrity of the protection concept has not been impaired.

1.6.2  Alarms and interlocks associated with pressurised equipment and the ventilation of spaces located in hazardous areas are to be tested for correct operation.

1.7 Unattended machinery space operation - UMS notation

1.7.1 In addition to the tests required by Vol 2, Pt 9, Ch 7 Control, Alerts and Safety Systems, the suitability of the installation for operation in the unattended mode is to be demonstrated during sea trials over a four to six hour period observing the following:

  1. Occurring alarms and the frequency of operation both during steady steaming and under manoeuvring conditions using bridge control.

  2. Any intervention by personnel in the operation of the machinery.

  3. Stable operation in, and transition between, power plant configuration modes which are not considered as manual operations (see Vol 2, Pt 9, Ch 1, 1.4 Documentation required for design review). The demonstration time of each operating mode for the electrical power system is to be sufficient to demonstrate that the transitions can be performed with an unattended engine room, and a stable running condition achieved.

1.8 Operation from a centralised control station - CCS notation

1.8.1 In addition to the tests required by Vol 2, Pt 9, Ch 7 Control, Alerts and Safety Systems, the suitability of the installation for operation from the centralised control station is to be demonstrated during sea trials.

1.9 Integrated platform management system failure

1.9.1 Where mobility type ship systems are operated through an Integrated Platform Management System (IPMS), a failure in the IPMS is not to render the ship’s system inoperable. Reversionary modes of operation are to be provided to ensure safe and graceful degradation under these conditions. The Systems Design Description shall define the acceptable levels of degraded performance.

1.10 Record of trials

1.10.1 Two copies of the alarm and control equipment test schedules, as required by Vol 2, Pt 9, Ch 1, 1.4 Documentation required for design review 1.4.25, signed by the Surveyor and Builder are to be provided on completion of the survey. One copy is to be placed on board the vessel and the other submitted to LR.


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