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29 - A. Shunt /motor/. В. Compound. С. Series
33 - 3 while, 4 which, since
34 - lj 2i 3k 4a 5f 6b 7d 8g 9e lOh 11c.
Section2
Тема: >uОсновные инструкции no эксплуатации машины ”.
Грамматический материал.
Употребление глаголов и система отрицаний.
Basic Topical Text
General Instructions for Maintenance д
1. For effective cooling & insulation, the machine must be kept clean & dry.
2. The cooling surface of the rib-cooled machines qjust be kept clean.
3. In the machines provided with air-to-water heat exchanger, the pipes of the heat exchanger must be kept clean by brushing them through with brush delivered with the machine.
4. In the machines provided with air-to water heat exchanger, the uncleanness in the water may form a gradually increasing layer of dirt on the inner surface of the heat exchanger pipes. This reduces the cooling capacity. Therefore the pipes must be cleaned from time to time with the brush delivered with the best exchanger.
5. To prevent corrosion, the water flow in the cooling pipes should be kept close to the value instructed by the manufacturer. Too high or too low flow is harmful.
6. When the water flow decreases too much, it is indicated by the water flow alarm device & by temperature rise in the circulating air, iron core & windings.
. 7. The condition of the,water flow alarm device can be checked by means of closing off the water circulation for a short while.
8. The instructions for mainenance of the air-to-water heat exchanger are usually delivered with the machine.
9. Open-type machines must occasionally be cleaned also inside. The uncleanness on the winding surfaces, especially the moisture & oil absorbed in the dust layer, cause easily damages in the windings.
10. The cooling ribs of the stator can be cleaned without cleaning tools delivered with the motor. Special care must be taken not to damage coil ends with the cleaning tools.
11. When the motor is started after cleaning, the detached uncleanness remaining in the ribs is taken by the motor ventilating air to places where it is easily removed.
12. The machines which have been unused for long periods of time, e.g. stand-by machines, must be kept in a dry place, especially if they have no anti-condense heaters. This prevents the moisture from penetrating to the bearings & windings. The machines must be rotated manually a few rounds now & then.
13. If, however, it is suspected that moisture has got into the machine, prior to starting up: -
1) lubricate the bearings or, preferably, remove the bearing cover for inspection & lubrication;
2) measure the insulation resistance between the windings & the body. In measuring, use the insulation resistance meter 0.5kV or lkV for low voltage & 1 ...2.5kV for high voltage circuits.
14. Insulation resistance is inversely proportional to the temperature of the winding & it is halved with each temperature rise of 10...15°C.
15. If the insulation resistance is less than the above limit value, the windings of the machine must be dried in a suitable way.
Задания на усвоение лексико-грамматического материала основного текста
1. /7 мин./ Прочтите основной текст. Скажите по-русски на какие важные моменты необходимо постоянно обращать внимание при эксплуатации машины.
2. /4 мин./ В абзацах 1-9 найдите предложения с информацией о том, что: а) ребристая поверхность охлаждаемых машин должна содержаться в чистоте б) загрязнение машин уменьшает эффективность охлаждения; в) для того, чтобы предотвратить коррозию, следует поддержиать такую величину скорости потока воды, какая указана в инструкции; г) грязь на поверхности обмотки
вызывает повреждение последней.
3. Прочитав текст до конца, скажите сколько в нем глаголов в отрицательной форме и назовите их / 3 мин./.
Словарь к основному тексту
4. / 5 мин./ Повторите вслух за преподавателем или прочтите с помощью словаря следующие слова и словосочетания. Затем прочтите их вслух самостоятельно, обращая внимание на русские эквиваленты. Постарайтесь запомнить как можно больше слов.
