Английский язык для судовых электромехаников - страница 54

4. Did you see such a system? If yes, where did you see it?

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29

Dwell on power plant control system, its design and operation with your fellow-student.

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Fill in the blanks with suitable words.

1. The electronic ... consist of identical boxes ... with different electronic . . . and fronts. 2. The boxes are made of . . . steel and . . . with ventilation holes. 3. A printed . . . board, the “mother board”, constitutes the . . . wiring and is ... to the terminal board by a . . . ribbon cable.

4. Together, these two .. . form the rear of the .. . 5. Some programming is ... by ... on the mother board. 6. The ... board has two rows each with 33 terminals for . . . connections.

31 6

Using the notes below speak on the boxes of the electronic units.

1. unit, consist, box, furnish, different, board, front. 2. box, make, sheet, provide, hole. 3. print, circuit, flexible, ribbon. 4. two, board, to form, rear. 5. program, perform, jumper, mother. 6. terminal, have, row, each, external, connection. 7. electronic, insert, front, box. 8. mount, indicate, lamp, push button, board, front, plate, contain, correspond, lamp glasses, engrave,

Complete the following sentences.

1. The maximum number of different electronic boards is seven and every board has a. . . 2. This implies that anv fault can easily be. . .

3. The relay and transformer units are built up in 19 inch standard racks and function as... 4. The basic units, the additional monitoring units and the central unit shall be supplied from a 24 V battery, while. . .

5. The system can be adapted to different types of. . .

33 5

Work in pairs. With a piece of chalk (pencil) explain the design of the power plant control system to your fellow-student.

34 2

What device is described in this text?

It is made up of a convertor module and a contactor unit. The contactor unit includes a main contactor, an auxiliary contactor and an auxiliary supply transformer to power and operate contactors and cooling-fans.

They can be supplied both connected together in an enclosure, or in the form of separate units without enclosure. Enclosed systems are supplied with an instrument unit, the basic version of which is fitted with the following controls: on, off, trip reset, alarm reset.

Say some words about thyristor convertors.

35 4

Translate at sight.

Convertor module is used in all systems. It is also available as a non-enclosed function module for the current range 40—1400 A.

The convertor module is a complete unit which has been tested for correct operation. It is made up of thyristor unit and convertor control

Fig 7. Converlor module

equipment. The convertor control equipment, in other words the electronic control circuits, consists of circuit boards mounted on a hinged panel. On convertor module 40—400 A the panel is supplied fixed in position; for the 650—1400 A module it is supplied separately.

The convertor control equipment is located on the inside of the panel. The permanent basic functions are grouped on one circuit board, known as the mother board. A number of optional functions in the form of small circuit boards can be connected to this mother board.

36 20

Home exercise. Write the exact translation of the second part of the text above. Be prepared to dwell on convertor module using Pig. 7.

Part II

Mounted on the outside of the. hinged panel is drive control cquip-

merit. The sub-functions are in the form of circuit boards connected to a mother board which provides all the internal connections between the sub-functions. Drive control equipment communicates with the convertor control equipment via a flat cable.

A convertor module can be fitted with all the options available for the convertor control equipment and the drive control equipment.

N. B. The open-core transformer for earth fault protection is supplied as a separate unit.

For supply voltages up to and including 500 V, the primary voltage of the auxiliary supply transformer is the same as the supply voltage of the convertor module. Where the supply voltage is higher, the transformer must be supplied separately with 500 V 60 Hz or 460 V 60 Hz.