Section 18 Trials

18.1.1 Before a new installation, or any alteration or addition to an existing installation, is put into service the trials in Pt 6, Ch 2, 18.2 Insulation resistance 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.

18.2.1 Insulation resistance is to be measured using a self-contained instrument such as a direct reading ohm-meter of the generator type applying a voltage of at least 500 V. Where a circuit incorporates capacitors of more than 2 μF total capacitance, a constant-voltage type instrument is to be used to ensure accurate test readings.

18.2.2  Power and lighting circuits. The insulation resistance between all insulated poles and earth and where practicable, between poles, is to be at least 1 MΩ. The installation may be subdivided and appliances may be disconnected if initial tests produce results less than this figure.

18.2.3  Low voltage circuits. Circuits operating at less than 50 V are to have an insulation resistance of at least 0,33 MΩ.

18.2.4  Switchboards, section boards and distribution boards. The insulation resistance is to be at least 1 MΩ when measured between each busbar and earth and between busbars. This test may be made with all circuit-breakers and switches open, all fuse links for pilot lamps, earth fault-indicating lamps, voltmeters, etc. removed and voltage coils temporarily disconnected, where otherwise damage may result.

18.2.5  Generators and motors. The insulation resistance of generators and motors, in normal working condition and with all parts in place, is to be measured and recorded. The test should be carried out with the machine hot, if possible. The insulation resistance of generator and motor cables, field windings and controlgear is to be at least 1 MΩ.

18.3.1 Tests are to be made to verify that all earth continuity conductors and bonding straps are effective and that the bonding and earthing of metallic conduit and/or sheathing of cables is effective.

18.4.1 It is to be demonstrated that the Rules have been complied with in respect of Pt 6, Ch 2, 18.4 Performance 18.4.2.

18.4.2 Satisfactory commutation and performance of each generator throughout a run at full rated load.

18.4.3 Temperatures of joints, connections, circuit-breakers and fuses.

18.4.4 The operation of engine governors, synchronizing devices, overspeed trips, reverse-current, reverse-power and over-current trips and other safety devices.

18.4.5 Voltage regulation of every generator when full rated load is suddenly thrown off.

18.4.6 For alternating current and direct current generators, satisfactory parallel operation and kW load sharing of all generators capable of being operated in parallel at all loads up to normal sea or harbour working load. For alternating current generators, satisfactory parallel operation and kVA load sharing of all generators capable of being operated in parallel at all loads up to normal sea or harbour working load.

18.4.7 All essential motors 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.

18.5.1 Voltage drop is to be measured, where necessary, to verify that this is not excessive, see Pt 6, Ch 2, 2.20 Current rating.