In electrical systems for the generation, distribution and use of electrical energy considerable control equipment is ne¬cessary. It can be divided into two classes: a) equipment used at the generating and distributing end; b) equipment used at the receiving end of the system. Safety switches are used at the point where the power en¬ters a building. They are of the knife type and are usually en¬closed in metallic boxes.

A magnetic contactor is used to make and break the circuit at the points where considerable power is used.

An automatic starter is a device which is used to keep the current from being excessive while the motor is obtaining full speed. It is a kind of a resistance inserted in series with the direct current armature. As the motor obtains speed it gradu¬ally removes.

Answer the questions:

1. Where is considerable control equipment necessary?

2. What classes can it be divided in?

3. Where are the safety switches used?

Махачкала является крупным туристским и лечебно-оздоровительным центром.  Благодаря тёплому климату и благоприятной геомагнитной обстановке, вблизи Махачкалы расположилось большое количество санаториев и лечебных центров. Махачкала расположена на узкой полосе низменной равнины западного побережья Каспийского моря между горой Тарки-Тау и морем, которая в далеком называлась «дагестанским коридором». Сегодня Махачкала — это крупнейший город российского Северного Кавказа и одноимённого федерального округа, культурный, экономический и научный центр Юга России.  Махачкала – единственный незамерзающий морской порт России на Каспии.

I live in Makhachkala - the capital of the southern Russia . I love this city , because here was born and raised . Enclosed in the arms of the sea and beautiful mountains , Makhachkala can not fall in love . So nice to see his hometown , which each year gets better : there are malls, buildings, beautiful waterfront. Evenings and at night the city does not know . Overall reflections of lights , colorful advertising dazzles on the facades of new retail stores, on the night road rush lights of cars.Like Makhachkala for what is a city of opportunities . You can achieve a lot , some effort . Fortunately, there is enough educational institutions .And I love the city for a peaceful attitude forecast to residents . She did not indulge , but not forced to relax in summer it's hot , and in winter - cool. Softens the climate effect of sea and mountains .Unfortunately , my city is not the most peaceful on earth. On the way to a brighter future to solve many problems. Since our Republic International, is necessary to establish the relationship between different nationalities , so that my children's future was bright and cloudless future .