Section 21 Testing and trials

21.1.1 Tests in accordance with Pt 16, 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 one 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 2.21.3 Test voltage and minimum insulation.

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 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 2.21.2 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 16, Ch 2, 21.2 Trials 21.2.2 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.

21.2.2 The insulation resistance is to be measured of all 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 2.21.3 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 16, Ch 2, 1.12 Earthing of non-current carrying parts 1.12.2 or Pt 16, Ch 2, 20.7 Earthing 20.7.2;

3. bonding for the control of static electricity.

Table 2.21.3 Test voltage and minimum insulation

Rated voltage	Minimum voltage of the tests, V	Minimum insulation resistance, MΩ
Un V
Un ≤ 250	2Un	1
250 < Un ≤ 1000	500	1
1000 < Un ≤ 7200	1000
7200 < Un ≤ 15000	5000
Un > 15000	5000

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 of harmonic filter failure during trials is not to exceed the THD limit. See Pt 16, 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. alarm sound pressure levels;
9. 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; and
10. satisfactory performance of each electrical propulsion, essential auxiliary or emergency energy store including its ancillary 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 16, Ch 2, 21.2 Trials 21.2.4.(c), Pt 16, Ch 2, 21.2 Trials 21.2.4.(d), Pt 16, Ch 2, 21.2 Trials 21.2.4.(e) and Pt 16, 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 16, Ch 2, 1.8 Quality of power supplies.

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

21.2.7 On completion of the general emergency alarm system and 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.