BASIC ELECTRONICS - OD1633 - LESSON 1/TASK 1
electricity but it is too expensive to be used in any great quantity.
Because of this, copper is the conductor most widely used in various
(2) Insulators. Whenever there are more than four electrons in the
outer orbits of the atoms of a substance, these electrons will tend to be
bound, causing restriction of free movement, making the substance an
insulator (figure 4 on the following page).
Common insulating substances
are rubber, plastic, Bakelite, varnish, and fiberboard.
Personnel should constantly be on the alert for any signs or indications
which might indicate a malfunction of electric equipment. Besides the more
obvious visual signals, the reaction of other senses, such as bearing,
smell, and touch, can warn of possible electrical malfunctions. Examples of
such signs are: fire, smoke, sparks, arcing, or an unusual sound from an
Frayed and damaged cords which feel warm to the touch;
slight shocks felt when handling electrical equipment; unusually hot-running
electric motors, and other electrical equipment which either fails to