Transport Publication TP 127 E
33.1 The initial inspection, which may consist of a series of inspections during the construction of the vessel, shall include a complete inspection of the electrical installation and electrical equipment or apparatus. The inspection shall be such as to ensure that the arrangement, materials and installations thereof, fully comply with the applicable section of this Standard and are in accordance with approved plans. The inspection shall also be such as to ensure that the workmanship of all equipment and apparatus and the installation thereof is, in all respects, satisfactory.
33.2 The insulation resistance shall be measured by self-contained instruments such as a direct reading ohmmeter of the generator type, applying a voltage of at least 500 volts. When an insulation test is made on a circuit incorporating capacitors of a total capacitance exceeding 2 microfarads, an insulation tester of the constant-voltage type should be used.
33.3 Before switchboards, motor control centres and distribution panels are put into service, their insulation resistance shall be not less than 1 megohm when measured between each bus-bar and ground and between each insulated bus-bar and the bus-bar connected to the other pole or poles; this test shall be made with all circuit breakers and switches open and all fuse-links for pilot lamps, ground indicating lamps, voltmeters, etc. removed and voltage coils temporarily disconnected.
33.4 On all lighting and power circuits, a test for insulation resistance between all insulated poles and ground and, where practicable, between poles shall be applied to all permanent wiring.
33.5 Each circuit should have an insulation resistance between conductors and between each conductor and ground of not less than the following:
33.6 All generating sets shall be run until constant temperature has been reached, after which commutation, electrical characteristics, overspeed trips, governing, range of excitation control, lubrication and absence of vibration shall be satisfactorily demonstrated.
33.7 The insulation resistance of all generators shall be measured both in the cold condition and in the warm condition immediately before and after running at normal full load.
33.8 All switchgear shall be loaded as nearly as practicable to its full load and no overheating shall take place due to faulty connections or incorrect rating. Those vessels with an aggregate connected load of 500 kW or more shall conduct a thermal scan of the switchboard main connections and bus work together with the generator connections and transformers above 10 kVA .
33.9 Switches and circuit breakers shall be operated on load and, where practicable, operation of their over-current, under-voltage and auxiliary trip units satisfactorily demonstrated.
33.10 Reverse power relays, reverse current relays, preferential tripping relays and all electrical and electro/mechanical interlocks shall be satisfactorily operated.
33.11 Each motor with all its associated control equipment shall be run under operating conditions for a sufficient length of time to demonstrate correct alignment, wiring, capacity, speed, and satisfactory operation; motors driving pumps, ventilation fans, and similar loads shall be operated as nearly as practicable under their individual service conditions; motors driving cargo winches shall hoist and lower their specified loads; motors driving warping capstans, machine tools, and other similar machines, shall be run to demonstrate suitability.
33.12 The remote control units for stopping ventilation fans, oil pumps and pumps discharging overboard in way of survival craft shall be satisfactorily operated.
33.13 Tests shall be carried out on power and lighting circuits to verify that the allowable voltage drop, as specified in Section 5.1 (b) of this standard has not been exceeded; circuits shall be operated as nearly as is practicable, at their full load rating during these tests.
33.14 Where the power developed by the main propulsion units is transmitted to the propeller by means of generators and motors:
- a dock trial of sufficient duration shall be made to prove that all propulsion machinery, controls and interlocks function satisfactorily;
- an insulation resistance test should be made on all motors, generators and main cabling in the cold condition immediately before the machinery is put into operation and in the warm condition immediately after completion of trials and the values obtained shall be not less than 1 megohm; the insulation resistance values obtained shall be recorded and kept onboard as a permanent reference for future insulation resistance tests.
33.15 The functioning of the complete emergency electrical supply shall be tested and this shall include the following; where applicable:
- operation of the emergency generator automatic starting system;
- operation of the transitional emergency battery automatic transfer system;
- capacity test of the emergency accumulator battery; and
- operation of the emergency lighting system.
33.16 Interior communications systems and alarm systems shall be tested to determine their suitability and to verify their specified functioning; particular attention shall be paid to the testing of the operation of all essential electrical communication systems including:
- electric engine order telegraphs;
- electric docking telegraphs;
- automatic fire alarm and detection systems;
- public address system; and
- general alarm system.
33.17 The operation of electric and electro/hydraulic steering gear shall be tested with particular attention paid to the function of the motor overload alarm, motor stopped indication and supply circuit breaker tripped alarm; where duplicate power supplies to a manual transfer panel are provided it shall be verified that the arrangement of switches or links on the panel is such as to permit either supply to be connected to either motor but not to permit both motors to be connected to one supply.
33.18 Electric cable shall be checked during installation for size and type as shown on the approved plans; the adequacy of cable supports shall be checked and it shall be ascertained that no cable is installed in the proximity of steam pipes or other hot objects and that the cables have not been damaged during the installation due to excessive pulling force having been applied, or due to bends or sharp or rough edges of cable supports or bulkhead penetrations or similar abrasions; cable penetrations required to be watertight shall be checked for proper packing of the terminal or stuffing tubes.
33.19 Rotating electrical machinery shall be checked to assure that rotating and/or un-insulated parts are adequately shielded from accidental contact by personnel.
33.20 Switchboards shall be checked for hand-rails, guard-rails, working spaces, insulating floor covering, drip covers and enclosures for backs and ends; switchboard mounted apparatus shall be checked for identifying nameplates; circuit nameplates shall be compared with the rating or setting of the overcurrent devices and with the approved plans; the accessibility of items requiring maintenance or adjustment shall be checked; meters shall be checked for proper operation; the operation of automatic switchgear and mechanical and electrical interlocks shall be observed.
33.21 Motor starters shall be checked to ensure proper starting of the motor under service conditions and that properly rated overcurrent devices are installed; each motor starter not completely disconnected from all sources of potential when the disconnect switch is opened (due to electrically interlocked circuits necessary for proper operation of the apparatus or for other valid reasons) shall be checked to ensure that attention is directed to such conditions by a suitable warning.
33.22 The accessibility of electrical apparatus for normal inspection and maintenance shall be observed; the accessibility of junction boxes and the like in way of panelling shall be noted during construction of a vessel; hinged doors of motor starters and similar apparatus shall be checked for interference with adjacent structural parts or apparatus.
33.23 It shall be determined that metal enclosures for electrical equipment are grounded, either by the method of mounting or by ground leads; portable equipment shall be checked for grounding through one conductor of the supply cable.
33.24 All propulsion and auxiliary machinery control and safety systems installed to comply with the requirements for an automated machinery system or an unmanned machinery space shall be checked for material condition and operation.
33.25 Storage batteries used for ship’s service and emergency diesel driven generator starting and diesel driven main engine starting shall be checked for capacity; the batteries shall have sufficient capacity without recharging to provide not less than twelve consecutive starts of each main engine if of the reversible type and not less than six consecutive starts if of the non reversible type; for diesel driven generators, not less than six consecutive starts.
33.26 Electric re-heat systems are to be checked for normal operation; overheat cut-outs are to be checked for proper operation and temperature rating; electrical connections are to be checked to ensure that they are tight; the interior of re-heat boxes is to be checked to ensure that they are free from excessive amounts of combustible dust.
34. Periodic Inspections
34.1 The inspection of electrical installations at the periodic inspection incident to re issuance of a safety certificate of inspection shall include an inspection of all items enumerated in Section 33.1 and 33.6 to 33.25 inclusive to the extent necessary to determine mechanical and electrical condition and performance and as per the applicable subsection of this chapter; particular note shall be made of circuits added or modified after the initial inspection.
34.2 All repairs, additions alterations are undertaken; shall comply with the approved plans.
34.3 Where the control of the propulsion machinery or the propeller is effected by electric or electronic means a complete inspection of the control system shall be conducted annually.
34.4 Where appropriate, in the interest of safety, more frequent inspections should be carried out.
34.5 Where the main source of electrical power is used for supplying power for lighting purposes only:
- the equipment and installation shall be generally inspected and tested under working conditions and electric cables inspected as far as may be practicable without dismantling any fixtures or casings;
- an insulation resistance test shall be made on generators, cables and fittings, using a direct indicating ohmmeter of the generator type, applying a d.c. voltage of 500 volts and the insulation resistance measured shall be not less than 100,000 ohms; for cargo vessels of less than 20 years of age the option exists whereby the insulation resistance tests may be performed on a five year periodicity; and
- all generators shall be run in turn or simultaneously, and all main switches and circuit breakers operated on load.
34.6 Where the main source of electrical power is also used for supplying power for driving essential auxiliary machinery, steering gear or windlass:
- generators and all motors driving essential auxiliary machinery shall be inspected generally as far as may be practicable without dismantling any fixtures or casings unless such dismantling is deemed necessary as a result of test or observation;
- an insulation resistance test shall be made on generators, motors, cables, heaters and fittings using a direct indicating ohmmeter of the generator type, applying a d.c. voltage of 500 volts; the insulation resistance measured shall be not less than 100,000 ohms; for cargo vessels of less than 20 years of age the option exists whereby the insulation resistance tests may be performed on a five year periodicity; and
- all generators shall be run in turn or simultaneously and all main switches and circuit breakers operated on load.
34.7 Where the power developed by the main propulsion units is transmitted to the propeller by means of generators and motors, an inspection shall be conducted as follows:
- the main propulsion generators and motors shall be inspected as far as may be practicable, particular attention being paid to the ends of all windings of stators and rotors; all air ducts in stator coils and the ventilating holes in rotors and retaining rings of alternators shall be carefully examined;
- all cable runs shall be examined over their entire length, particular attention being paid to the grounding of metallic protective coverings of sheaths;
- generator circuit breakers and set-up switchgear shall be examined and tested for mechanical operation at no load;
- high potential bus insulators and supports shall be inspected and found free from oil, dust or contamination liable to cause tracking to ground;
- The propulsion system excitation and control systems shall be energized and all permissive interlocks and indicators inspected; the excitation and control power need not be applied to the main machinery during this inspection; and
- the insulation resistance of each propulsion motor and generator shall be tested and the values obtained compared with the original readings and those in the ships log; corrective action shall be requested where the measured insulation resistance is less than 1 megohm or where any abrupt decrease in the order of 25% of the original or previously recorded values are noted.
34.8 The functioning of the complete emergency electrical supply system shall be tested and this shall include the following, where applicable:
- operation of the emergency generator automatic starting system;
- operation of the transitional emergency battery automatic transfer system; and
- operation of the emergency lighting system.
34.9 All essential electrical communication systems shall be tested to verify their specified functioning.
34.10 The operation of electric and electro/hydraulic steering gear shall be tested with particular attention paid to the functioning of the motor overload alarm, motor stopped indication and supply circuit breaker tripped alarm, also the setting of switches or links on the transfer panel where applicable.
34.11 Generator circuit breakers for generators rated 100 kW and above shall be tested every five years to verify initial trip settings and satisfactory operation; the tests may be conducted using either primary or secondary injection methods; if the test is performed by secondary injection the integrity of all the circuit breaker’s associated current transformers is to be verified on a ten year periodicity. The actual generator circuit breaker settings shall be permanently indicated in an accessible position within each circuit breaker compartment.