Английский язык для моряков / Труханова Англ для моряков

According to the voltage: the rated voltage on the electric powef supply terminals should not exceed: a) at a direct current - 230 V; b) at a one-phase alternating current - 270V; c) at a three-phase alternating current - 460 V.

According to the mode of control, there recognized: a) non-automated, b) partially automated; c) automated power stations.

DISTRIBUTION (SWITCH-) GEARS

Distribution gears are such constructions which serve to accommodate commutating, protective, regulating, signalling apparatuses and electric measuring devices. Thus, they ensure control, protection and regulation of electric installations and power plants operation as well as measuring of electric power supply sources parametres.

Distribution gears are classified according to their function, kind of current, design, mode of installation and fastening.

According to the function, there distinguished: a) main distribution boards (switchboards), intended for control, protection and regulation of basic generator units parametres as well as for electric power distribution over its consumers; b) emergency distribution boards, performing the same function as the main ones but for emergency generating units and their consumers; c) control panels (consoles), exerting remote control and control over the generating units and essential power consumers operation; d) coastal power supply boards, intended for energy delivery from the coast or from other ships; e) switchboards, which serve to ensure power supply in a certain part of a ship. They are supplied from main or emergency distribution boards; f) separate consumers boards, exerting control over operation of essential consumers, having a complicated mode of operation; g) electric power converters boards are similar to main distribution boards but designed for electric power converters and their consumers.

According to the kind of current, there recognised switchgears of a) direct current, b) alternating one-

phase and three-phase current.

According to their design, switchgears can be: proof, drop-proof, splash-proof, water-proof and watertight, explosion-proof, hermetic.

According to the mode of installation and fastening, there can be a) suspended switchgears of a leaning type, which are installed on a

QUESTIONS

1. What does the notion "ship's power plant" include?

2.How are ship's power plants classified?

3.What is the classification of ship's power plants according to their function?

4.How are power plants classed according to the type of primary motor?

5.What modes of control are used for ship's power plants?

6.What do switchgears serve to? What do they ensure?

7.What are the principles of classification of switchgears?

8.How are switchgears classified according to their function?

9.What is the function of main distribution boards?

10.What is the difference between emergency distribution boards and main ones?

11.What are the functions of:

■control panels?

■coastal power supply boards?

■switchboards?

■separate consumers boards?

■electric power converters boards?

12.What currents can switchgears run on?

13.What peculiarities of switchgears' design do you know?

14.How can switchgears be installed on board ships?

2.POWER PLANT SWITCHGEAR EQUIPMENT

According to the function, switchgear equipment is subdivided into (twitching, protective, switchingprotective, measuring, control and signaling equipment.

Switching equipment serves for electric circuits switching-in, switching-off and switching-over. Among

switching equipment are: knife SWitches, knife-blade-type switches, packet switches and universal

switches

Protective equipment is intended for protection of electric energy sources, circuits and consumers against overloads, short-circuits, voltage drop, inverse current and inverse power. Among protective equipment are fuses and relays.

Switching-protective equipment is applied for electrical installation switching-in, switching-off and protection. Automatic switches of different types refer to this kind of equipment.

Measuring equipment (ammeters, voltmeters, wattmeters, phasometers, megohmmeters and synchronoscopes) is destined for the control over the electrical installation normal operation.

Control equipment is intended for stabilization and control of the electric circuits preset parameters. It can be manual or automatic. Among manual control equipment are rheostats of different types and excitation controllers.

Signaling equipment is designed for signaling about the electric circuits state and the position of the

switching equipment. It includes light and audible signaling devices.

QUESTIONS

1.How is switchgear equipment subdivided according to its function?

2.What does switching equipment serve for?

3.What is protective equipment intended for?

4.What is switching-protective equipment applied for?

5.What is measuring equipment destined for?

6.What is control equipment intended for?

7.What is signal equipment designed for?

3. SHIP'S POWER NETWORK

Ship's power network is a complex of electric cables, wires, nwitchgears and accessories, which serve for electric power delivery to the consumers.

According to their function, networks are divided into:

■ Power mains, intended for power consumers' supply, i.e. different electric drives and powerful

electric heating devices.

■General lighting network, which, in its turn, is subdivided into: и) ship's accommodations lighting network; b) engine room and boiler room lighting network; c) outside lighting network; d) hold lighting network.

■Emergency lighting network, which is supplied from the main distribution board through the emergency distribution board and usually Has no switches.

■Battery-powered emergency lighting network, which is «witched on automatically, when the

voltage on the main or emergency distribution board vanishes.

■Portable low-voltage lighting network, which is used while exttmining and repairing the equipment. It is supplied through bucking transformers or, if electric power distribution is performed on normal voltage, through plug-transformers.

■Light-current installations network includes engine and rud-

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der telegraphs networks, tachometers, salinometers, pyrometers, resii tance thermometers networks as well as networks of telephone comma nication and alarm ( fire, emergency, watch, etc.)

■ Electric radio navigation equipment network comprises g; rocompass, echo sounder, log, radio pelorus etc. networks.

Electric networks are made of ship's cables and wires. The ship* cable is one or several isolated electric conductors, having one or seM eral mutual protective shells, which guard isolation and current-carry! ing conductors against mechanical and chemical effects. Marine powal cables isolation is mostly rated for 700 V of direct current and 1000 4 of alternating current. In accordance with the type of protection the ctr bles are divided into: non-hermetic (which are not protected again» moisture), hermetic (protected against moisture in both radial and Ion gitudinal directions), iron-clad (protected against mechanical damage: and shielded

(protected against interference during radio reception anA against mechanical damage).

VOCABULARY

сеть силовая сеть сеть основного освещения ~ освещения судовых помещений 1 ~ наружного освещения ~ трюмного

освещения ~ ~ аккумуляторного аварийного ~

~ низковольтного переносного ~ J установка слабого тока машинный телеграф рулевой телеграф арматура исчезать

ship's accommodations~ освещения судовых

1.Вакуумные трубы приводят в движение эту машину.

2.Реле служит для приведения в движение механизма циферблат (dial mechanism) часов.

3.Станки (machines) на этом заводе приводятся в движени двигателями переменного тока.

То test

1.Электрик проверил электрическое оборудование перед пуском.

2.Для проверки этой гипотезы (hypothesis) ученые провели сери экспериментов.

3.Машина была дважды проверена, прежде чем ее пустили эксплуатацию.

То change

1.Чтобы изменить ситуацию к лучшему, вам следует обратит больше внимания на работу этого

блока.

2.Электрический ток, который меняет и величину и направление в определенный интервал времени, называется переменным током.

3.Хотя курс судна и был изменен в последний момент, они не смогли избежать столкновения.

To explain

1.Принцип запуска этой машины трудно объяснить. Лучше я покажу.

2.Им объяснили важность соблюдения правил безопасности мореплавания.

3.Старший механик объяснил новому электрику, что в его обязанности входит ежедневный осмотр судового электрооборудования.

То show

Курсантам показали машинное отделение, в котором они будут проходить свою первую плавпрактику.

Курсантов провели в машинное отделение, чтобы показать, где они будут проходить свою первую плавпрактику.

Термометр показывает 25° ниже нуля.

UNIT 8.

OPERATION AND MAINTENANCE OF SHIP'S ELECTRIC MACHINES

1. WATCH MAINTENANCE

Service life and reliability of the electrical equipment largely depend on its proper operation and

maintenance, namely, watch mainte-j nance, maintenance (work) and repairs.

Watch maintenance ensures electric machines readiness for operation, the change of their mode of operation as well as starting and! shutdown operations supervision.

Normal operation of electric machines includes: correspondence] of the operating parameters to the rated ones (voltage, current, current' frequency, speed of rotation and number of startings); the degree of heat-j ing

of separate machine parts; the condition of the insulation resistance] the proper operation of the protective and signalling equipment, the сом rect instrument readings, etc.

After repairs or long inaction electric machines should be tested thoroughly. Trial start is usually performed under idling conditions. Then] the load is gradually upped to the rated one.

When the generator runs under nominal load, the personnel of watch should make sure that the switch apparatuses are in good work-' ing order, there is no inadmissible sparking on the commutator and rings, the voltage regulators are operating properly, the frequency is normaU When the generators are working in parallel, watch personnel should check the operation of both synchronizing apparatuses and electric mea«! suring devices. They should observe that the voltage and frequency are

of rated values, and that the load between generators, working in parallel, is distributed properly; they should also check the isolation resistance condition.

While working with shaft generators, the watch personnel should observe the generator drive condition and fluctuations in voltage and frequency.

During preparation of electric motors for operation, the personnel of watch should perform superficial examination of both the electric motor and the driving mechanism (electric drive), check the position of the starters, the condition of the electromagnetic and mechanical brakes, and measure the insulation resistance of the electric drive and the equipment together with the feeding cables.

In case the motor doesn't reach the required frequency, or consumes high-amperage current, or tends to overspeed, it should be immediately stopped and started only after the fault is remedied.

While examining the electric drives the watch personnel should check that the switch apparatuses operate properly, and that there is no sparking on the electric motors rings and commutators; examine electric machines for local overheating; test the condition of the signaling system and measuring devices.