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Файл:English for marine electro-technical officers. Supplementary book. Учебное пособие
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81
(if fitted). The cable must, of course, be adequately supported
along horizontal and vertical runs by suitable cable clips
or ties.
Where cable-runs along an open deck have expansion
loops, these must be examined for abrasion and wear.
Where cables pass though fire check bulkheads they
must be correctly glanded or pass through stopper boxes which
prevent the passage of fire between compartments.
Probably the most common ship-board cable insulations
used are EPR (ethylene propylene rubber) or butyl rubber
which is sheathed with either PCP (polychloroprene) or CSP
(chlorosulphonated polyethelene).
Where EPR / butyl cable terminations may be subjected
to oil vapour it is usual to tape or sleeve the cable ends to prevent deterioration of the insulation. Check that such taping is
secure.
Flexible cables to light fittings, power tools, etc., should
be inspected for mechanical damage. In normal operation
a flexible cable may be repeatedly dragged and chafed so reducing its safety. If in doubt replace flexible cables.
A copper strap or flexible earthing braid / wire is used
to bond the steel frame of all electrical motors and other
equipment to the ship's hull.
82
Answer the questions:
1. What does an obvious survey requirement for any
switchboard, section board or distribution board include?
2. What should all the main bus-bar and auxiliary con-
nections throughout the boards be checked for?
3. Why should cable entries at the bottom of the
switchboard be sealed with a non-flammable material?
4. Why must feeder isolator and fuse holder contacts be
checked for any mechanical wear or damage?
5. When must cable-runs be examined for abrasion and
wear?
6. What is the most common ship-board cable insula-
tions?
Words and expressions (6.7, 6.8)
recent insulation test
недавняя проверка изоляции
to witness a repeat test
для наблюдения
за повторным тестом
motors with drop proof,
weatherproof and deckwatertight enclosures
двигатели с каплезащитными,
влагозащитными
и водонепроницаемыми
корпусами
ingress of oil and water
проникновение масла и воды
83
reveal any vibration problems, undue noise and
worn out bearings
выявить причины вибрации,
чрезмерного шума
и изношенные подшипники
to check for badly burned
and misaligned contacts
проверить на наличие сильно
подгоревших
и рассогласованных контактов
loose connections
ослабленные соединения
worn pigtails on moving
contacts
изношенные короткие
проволочные выводы
на движущихся контактах
badly carbonized arc-chute
сильно карбонизированная
дугогасительная камера
remote and emergency
control
дистанционное и аварийное
управление
6.7. Insulation resistance
The surveyor will require a list which shows the results
of recent insulation tests on all main 440 V and 220 V circuits.
Such a list should also indicate the test date's, weather
conditions (hot, humid, etc.) together with any comments relevant to the test conditions (e.g. machine hot or cold).
For essential items such as generators and main motors,
the surveyor will be more interested in the IR trend, so a set of
84
past results showing the insulation history of such machines
may be requested.
6.8. Motors and starters
After checking through the IR test results list, a surveyor may ask to witness a repeat test on selected motors. A visual
examination of a motor frame and terminal box will reveal any
damaged or missing parts. General neglect will be suspected if
the motor is covered with dirt, oil or rust.
Totally enclosed fan ventilated (TEFV) induction motors require little attention as their windings are protected
against the external atmosphere. The surveyor will be more
likely to concentrate on motors with drip proof, weatherproof
and deck-watertight enclosures. It may be necessary to open up
such motors to check for ingress of oil and water which could
damage insulation and cause internal corrosion.
Special machines such as d.c. commutator or a.c. slipring types used, for example, on an electric windlass, must
have their rotary contacts and brush gear checked.
Cargo cranes and winches are not strictly part of a survey as they are not considered essential to the safety of the
ship.
A running test on a motor will reveal any vibration
problems, undue noise and worn out bearings. On-load, the
motor running current (shown on the ammeter at the starter)
85
should be checked against the value indicated on the motor rating plate.
With starters and associated control gear such as remote
stop / start buttons, regulating resistors etc., an inspection will
check mainly for badly burned and misaligned contacts. The
general condition of starter equipment will also be examined.
This would include an inspection for loose connections, worn
pigtails on moving contacts, badly carbonized arc-chutes and
signs of overheating on coils, transformers and resistors. Dust
and weather-proof sealing features on a starter must be in place
and in a serviceable condition.
Functional checks will test the normal operation of the
starter from its local, remote and emergency control (if applicable) positions. Signal status lamps showing the motor / starter condition, e.g. running, off, tripped, etc., must be demonstrated as working correctly. Overcurrent trip settings should
be compared with the motor full-load current (FLC) rating.
Motor starter back-up fuse size and type may be checked
against the ship's / manufacturer's drawings and the motor rating.
Answer the questions:
1. What should a list which shows the results of recent
insulation tests indicate?
2. Why do totally enclosed fan ventilated (TEFV) in-
duction motors require little attention?
86
3. What does a running test on a motor reveal?
4. What does the general condition of starter equipment
inspection include?
Words and expressions (6.9, 6.10)
electrical interlocking
arrangements
система электроблокировки
auto-start initiation relay
реле автозапуска
charging rectifier
выпрямитель для зарядки
аккумулятора
power unit
силовой агрегат, энергоблок
to supply
снабжать, обеспечивать,
поставлять
changeover facilities for the
electric control from the
steering wheel
средства переключения
электрического управления
с руля
motor overcurrent alarm
сигнализатор перегрузки
двигателя
6.9. Emergency power and associated equipment
This section surveys the operation of the emergency
generator and / or battery power equipment (inspection of the
87
emergency generator itself is covered under the heading of
Generators and Governors).
The emergency generator must be started, manually or
automatically, while the initiation sequence and operation of
starting equipment is observed.
Electrical supplies taken from the emergency switchboard should be checked as receiving their rated voltage, current and frequency when powered from the emergency generator.
Emergency lighting, fire pump and other emergency
electrical equipment must be functioning correctly. Electrical
interlocking arrangements between main and emergency
switchboard must be checked. Auto-start initiation relays,
whether voltage or frequency operated, will be examined and
tested.
The ship's emergency battery installation and its charging rectifier will be examined. In particular the battery environment must be dry and well ventilated. The battery tops must
be clean with terminal posts and connections appearing free
from corrosion.
Grease all connections with petroleum jelly. Battery
electrolyte should be at its proper level and have the correct
value of specific gravity (SG) as checked on a hydrometer.
Safety notices and personnel safety clothes (gloves, apron and
goggles) should be available adjacent to the batteries. The ventilation arrangements for the battery locker will be checked.
88
Battery charging equipment should be given the normal
checks for dirt, over-heating, loose connections and correct
functioning of indicators, instruments and alarms.
6.10. Parts of steering gear
An electrohydraulic steering gear system can be envisaged from the surveyor's viewpoint as being in three parts:
- power unit;
- steering control;
- indications and alarms.
The power unit comprises duplicate electric motors and
starters supplied from either side of the main switchboard.
On many ships one of the steering gear motors will be
supplied via the emergency switchboard as recommended by
the SOLAS requirements for certain vessel types, e.g. passenger ships and ferries.
The motors, starters and any changeover supply switch
units will be inspected under the same criteria outlined earlier
in the section on Motors and Starters.
Rudder control from the bridge position may be via
a hydraulic telemotor or via an electric controller or both. Main
and alternative electric supplies, including any changeover facilities for the electric control from the steering wheel and for
the auto pilot, must be tested.
89
The steering gear and its control must be functionally
tested for its response. This is generally specified to be that the
rudder must be swung from 32° port to 32° starboard in
28 seconds. Note, a fully loaded response can only be obtained
when the ship is loaded and under way at sea. Steering gear
status indications must be operating correctly in the steering
flat, main control room and on the bridge. The rudder position
indicators on the bridge may be checked during the functional
testing of the steering gear. The bridge indication should be
compared with the direct mechanical indicator on the rudder
stock in the steering flat.
Motor overcurrent alarms can be initiated by simulating
the action of the overcurrent relay. Remember that a steering
gear motor does not have overcurrent trip protection; the only
main circuit protection being from the back-up fuses which are
essential for short-circuit protection. Hydraulic fluid low level
alarms, if fitted, must be checked for correct initiation by the
oil level sensors.
Answer the questions:
1. How must the emergency generator be started?
2. What is the ship's emergency battery and battery
charging equipment checked for?
90
Words and expressions (6.11, 6.12)
Unattended Machinery
Space (UMS) operation
безвахтенное машинное
отделение
one pump can be selected
on a duty / standby
один насос может быть
выбран в качестве резерва
to accomplish
выполнять
automatic sequential restarting of essential auxiliaries for lubrication, cooling,
fuel and steering.
автоматический последова-
тельный повторный запуск
основных вспомогательных
устройств для смазки, охла-
ждения, топлива
и рулевого управления
to verify
проверить
to initiate the appropriate
audible and visual alarms on
the bridge
поднять звуковую и визуаль-
ную сигнализацию на мостике
to examine for wear and
tear, insulation level, cleanliness, loose connections
and overheating
проверить на износ, уровень
изоляции, чистоту, слабо
закрепленные соединения
и перегрев
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