The relevance of power in our life is unquestionable.It lights our residences, our transferring appliances, allows the procedure of electronic gadgets and warms our bathtub.On the other hand, the electrical power when misused delivers some hazards as shock, at times lethal, and quick circuits, triggering a lot of fires.The ideal way to get along in harmony with electricity it is identified, by getting absent the most of experiencing all your ease and comfort with optimum basic safety.The purpose of this publication is to provide, in basic and accessible language, the most important data concerning what is electricity, it is an electrical installation, which its main factors, it scales them and select them.