LESSON 4. LIGHTING PROTECTION

Exercise 1. Read and learn the following words and word-combinations.

Exercise 2. Read and translate the text.

LIGHTING PROTECTION

If you're considering installing a lightning protection system, here's a statistic to consider. According to data compiled by Westinghouse Electric Company, given an average location and exposure, a 50 ft. high building stands a greater chance of being struck by lightning once a year than a card player has of filing an ordinary flush in a poker game. In the United States the average geographic area is subjected to 40 lightning strokes per square mile every year.

A lightning protection system uses lightning rods (air terminals), a conductor system to conduct the lightning discharge harmlessly between the rods to ground terminals. Other components include surge arrestors to protect power lines and associated equipment from direct discharges and inducted currents. Secondary conductors are also used to prevent "sparkover" as the discharge travels to the ground terminals.

Lightning rods do not "attract" lightning. Their sole-function is to act as a contact point so the lightning can be harmlessly grounded. While every structure is electrically grounded it doesn't have the capacity to handle the tremendous electrical force of lightning.

Lightning basics: Some areas are more likely to be struck by lightning than others, but all are at risk. Water environs, flat lands, mountain tops, tall trees and tall buildings in urban areas are particular areas of concern. The parts of structures most likely to be struck are projecting parts such as chimneys, ventilators, flag poles, tower, deck railings, and skylights.

Location and soil condition information is also important for maximum grounding purposes. The pitch of a roof will affect the amount of labor and accessibility to areas where rods will be installed. The edge of a roof is the part of a structure most likely to be struck on flat roofed buildings.

Exercise 3. Translate the following words and word combinations into Russian

According to, an average location and exposure, lighting protection system, to be subjected to, data compiled, harmlessly, lightning rods, inducted current, to protect power lines, ground terminal, lightning strokes, to attract, to act as a contact point, to handle, water environs, likely, tremendous electrical force, chimney, areas of concern, pole, skylight, the pitch of a roof, edge.

Exercise 4. Find the English equivalents in the text

Молниезащита, система электропроводки, зажим заземления, выступающие части (сооружений), выступать в качестве контакт-детали, искрение, управлять огромной электрической силой, удары молнии, согласно собранным данным, разрядник для защиты от искровых перенапряжений, стержневой молниеотвод, уклон ската крыши; столб, на который крепится флаг; дымовая труба, здания с плоской крышей, световой фонарь, разряд.

Exercise 5. Answer the following questions:

1) What buildings stand a greater chance of being struck by lightning according to statistics?

2) How often is the average geographic area in the United States subjected to lighting strokes?

3) What components does the lightning protection include?

4) What is the function of the conductor system?

5) What for is the surge arrestor needed?

6) What can the secondary conductors prevent?

7) What is the function of lightning rods? Do they "attract" lightning?

8) What areas are more likely to be struck by lightning than others?

9) What is important for maximum grounding purposes?

10) What part of a structure is more likely to be struck on flat roofed buildings?