27 5
Listen to paragraphs 1—4, read sentence by sentence and translate them orallv in pauses.
28 4
Respond to the questions. Compare the results with the text.
1. What units does the power plant control system comprise of?
2. What are in your opinion the specific features in the design of the system?
3. What is meant by the “mother board”?
4. Did you see such a system? If yes, where did you see it?
6
29
Dwell on power plant control system, its design and operation with your fellow-student.
2
30
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.