Basic Electrical Installation Work

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Other methods basic protection include the provision barriers or enclosures which can only opened the use tool, when the sup- ply first disconnected.Overcurrent, short circuit and earth fault protection 235 Protective equipotential bonding this equipotential bonding for the purpose safety shown Fig. . Indirect contact results from contact with exposed conductive part such as the metal structure piece equipment that has become live a result fault. Two types contact will result person receiving electric shock. Basic protection and fault protection The human body’s movements are controlled the nervous system. Very tiny electrical signals travel between the central nervous system and the muscles, stimulating operation the muscles, which enable walk, talk and run and remember that the heart also muscle.1). The shock current causes unnatural operation of the muscles and the result may that the person unable release the live conductor causing the shock, the person may thrown across the room. Protection can also provided fixed obstacles such guardrail around open switchboard placing live parts out of reach with overhead lines. Definition Protective equipotential bonding this is equipotential bonding for the pur- pose safety shown Fig. The Regulations call this fault protection. The current which flows through the body determined the resistance the human body and the surface resistance the skin the hands and feet. 6. This leads the consideration exceptional precautions where people with wet skin wet surfaces are involved, and the need for special consid- eration bathroom installations.7 this book.2. Try This Definitions ● help you remember these definitions try writing them out your own words ● just identify the essential words. Direct contact with live parts which involves touching terminal line conductor that actually live. The IEE Regulations call this basic protection (IEE Regulation 131. 6. The Regulations call this basic protection. If the body becomes part more powerful external circuit, such the electrical mains, and current flows through it, the body’s normal electrical operations are disrupted. The insulating material must, course, suitable for the circumstances which they will used and the stresses which they will subjected. All live parts are enclosed in insulating material such rubber plastic, which prevents contact with those parts. In installations operating normal mains voltage, the primary method of protection against direct contact insulation.7 of this book