Практическая работа № 16

FUSES

Цели: Введение и активизация в речи лексики по теме « Плавкие предохранители».

Оборудование: комплект тестов, раздаточный материал.

Vocabulary

I. Learn the words and expressions.

Fuse Link Fault Faulty Equipment Installation To protect To utilize To equip To serve To melt Up to II. Read and translate the text.

плавкий предохранитель звено, связь дефект, неисправность неисправный оборудование установка; защищать, предохранять использовать оборудовать, снаряжать служить плавить вплоть до

Fuses are widely used nowadays as protection devices. They are utilized in various circuits, electrical equipment and installations. .Fuses serve to protect them against over currents and short-circuits.

There are different types of fuses in use nowadays. Quartz-sand fuses serve for voltages up to 500 volts; fuses of this kind are pro­duced with current ratings of 15 to 60 amp and of 100 to 350 amp.

Fuses are commonly used in low-voltage industrial installations rated up to 1,000 V.

Fuse protection is based on a very simple principle: in case of a short-circuit or overcurrent, when the maximum value of current has been exceeded, the fusible link of a fuse is heated to its melting point. This opens the circuit and disconnects the circuit from the power source. In case of a fault, one should replace the faulty fusible element by a new one.

Fuses are used both in direct current and alternating current circuits.

III. Find English equivalents.

Звено, дефект, неисправный, оборудование, установка, служить, вплоть до, использовать, плавить, защищать.

IV. Finish the sentences.

1. Fuses are widely used………….

2. Fuses serve to………………….

3. Quartz-sand fuses serve………..

4. Fuses are commonly used………

5. Fuse protection is based on……..

6. Fuses are used both in…………..

V. Insert the missing letter.

Equi-ment , insta-lation, uti-ize, qu-rtz, exc-ed, prin-iple, ind-strial, fu-ible.

VI. Make up the sentences.

1. devices used nowadays. Fuses are widely as protection

2. fuses in different nowadays types are of use There

3. is simple principle based Fuse very on a: protection

4. are used Fuses direct both in and current alternating current circuits.

5. This opens the circuit and the circuit disconnects the power from source.

VII. Complete the sentences using the correct variant:

1. A fuse serves a) as a load.

b) as a protection.

2. Fuses are used a) for d.c. only.

b) for both a.c. and d.c.

3. In case of a fault a) the whole fuse should be replaced.

b) the faulty link should be replaced.

4. Fuse protection is based on a) a simple principle.

b) a complex principle.