Section 21 Testing and trials

21.1.1 Tests in accordance with Pt 6, Ch 2, 21.1 Testing 21.1.2 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.

21.1.2 A high voltage at any frequency between 25 and 100Hz 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 2.21.1 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.

21.1.3 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.

21.1.4 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 2.21.2 Test voltage and minimum insulation.

Table 2.21.2 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

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

21.1.6 Tests at the manufacturers’ works and trials after installation on board are to include such tests necessary to demonstrate the suitability and safety of the lithium battery system for its intended duty and location. As a minimum, the tests listed in Table 2.21.3 Test requirements on lithium battery systems are required:

21.2.1 Before a new installation, or any alteration or addition to an existing installation, is put into service the applicable trials in Pt 6, Ch 2, 21.2 Trials 21.2.2 to Pt 6, Ch 2, 21.2 Trials 21.2.7 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.

21.2.2 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 2.21.2 Test voltage and minimum insulation. The installation may be subdivided and appliances may be disconnected if initial tests produce results less than these figures.

21.2.3 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 Pt 6, Ch 2, 1.12 Earthing of non-current carrying parts 1.12.2;

3. bonding for the control of static electricity.

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

1. satisfactory performance of each electrical propulsion, essential auxiliary or emergency power source including its ancillary 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. Simulation on trials of harmonic filter failure that would result in THD levels calculated to be higher than the acceptable limit are to be avoided. See Pt 6, Ch 2, 5.11 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 essential 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. In passenger ships 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; and

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 Pt 6, Ch 2, 16.5 Harmonic filtering for propulsion 16.5.2; 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 electrical propulsion, essential auxiliary or emergency energy store including its auxiliary services throughout a run at full rated charging capacity.

21.2.5 Measurements are to be taken as part of the trials specified in Pt 6, Ch 2, 21.2 Trials 21.2.4.(c), Pt 6, Ch 2, 21.2 Trials 21.2.4.(d), Pt 6, Ch 2, 21.2 Trials 21.2.4.(e) and Pt 6, Ch 2, 21.2 Trials 21.2.4.(f) to verify that the installation will provide a quality of power supply in accordance with the values listed in Pt 6, Ch 2, 1.8 Quality of power supplies.

21.2.6 Satisfactory load management in accordance with Pt 6, Ch 2, 6.9 Load management is to be demonstrated. The demonstration is to include verification that the requirements of Pt 6, Ch 2, 1.8 Quality of power supplies will be met following disconnection of a generator under all defined operating profiles as agreed with the operators.

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

21.2.8 On completion of the general emergency alarm system and the public 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.

21.3.1 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 Pt 6, Ch 2, 21.2 Trials 21.2.2 and may use either an a.c. voltage at power frequency or a d.c. voltage.

21.3.2 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.

21.3.3 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 electrical charge. An insulation resistance test in accordance with Pt 6, Ch 2, 21.2 Trials 21.2.2 is then to be repeated.

21.4.1 Where on-line partial discharge monitoring equipment is installed for the monitoring of high voltage rotating machines used to provide essential services, 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.

21.4.2 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.

21.4.3 The test reports required by Pt 6, Ch 2, 21.4 On-line partial discharge testing of high voltage rotating machines for essential services 21.4.1 are to:

• record the method and equipment used in sufficient detail to ensure that 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.

21.4.4 Where partial discharge monitoring equipment has been installed in accordance with Pt 6, Ch 2, 21.4 On-line partial discharge testing of high voltage rotating machines for essential services 21.4.1, 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.

21.5.1 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.

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

21.6.1 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.

21.6.2 The attenuation loss of multi-mode 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.

21.6.3 The tests required by Pt 6, Ch 2, 21.6 Optical Fibre Communications Systems 21.6.1 and Pt 6, Ch 2, 21.6 Optical Fibre Communications Systems 21.6.2 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.

21.6.4 The results of the testing required by Pt 6, Ch 2, 21.6 Optical Fibre Communications Systems 21.6.3 are to be validated against the communication system design specification to ensure that adequate optical power will be transmitted for correct system operation, see Pt 6, Ch 2, 1.2 Documentation required for design review 1.2.10.