Basic Electrical Installation Work

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It good insulator, but degrades and becomes brittle when exposed to sunlight. Ferrous word used describe all metals which the main constituent is iron. Definition Non-ferrous Metals which not con- tain iron are called non-ferrous. Thermosetting polymers Once heated and formed, products made from thermosetting polymers are fixed rigidly. They are good insulators, but give off toxic fumes when burned. Non-ferrous Metals which not contain iron are called non-ferrous. Polyvinylchloride (PVC) used for cable insulation thermo- plastic polymer. Plug tops, socket outlets and switch plates are made from this material. What makes them differ- ent materials the way which the atoms and electrons are arranged and how strongly the electrons are attracted the atoms. Definition A conductor material, usually a metal, which the electrons are loosely bound the central nucleus. The word ‘ferrous’ comes from the Latin word ferrum meaning iron. Ferrous metals have magnetic properties. Let now define the terms and properties some the materials used in the electrotechnical industry. Synthetic rubber manufactured, opposed being produced natu- rally. Copper, aluminium, tin, lead, zinc and brass are examples non-ferrous metals. Corrosion The destruction metal chemical action. They have a flexible quality when operated maximum temperature 70°C but should not flexed when the air temperature near 0°C, otherwise they may crack. Definition Corrosion The destruction metal by chemical action. Rubber tough elastic substance made from the sap tropical plants. An insulator material, usually non-metal, which the electrons are very firmly bound the nucleus and, therefore, will not allow heat elec- tricity pass through it.Basic Electrical Installation Work 100 Properties conductors and insulators In Fig. Thermoplastic polymers These may repeatedly warmed and cooled without appreciable changes occurring the properties the material. A conductor material, usually metal, which the electrons are loosely bound the central nucleus. Alloy alloy mixture two more metals.1 the last chapter looked the atomic structure materials. These electrons can easily become ‘free electrons’ which allows heat and electricity pass easily through the material. Definition Polyvinylchloride (PVC) used for cable insulation thermoplastic polymer. Most corrosion takes place when metal contact with moisture (see also mild steel and zinc). Synthetic artificial rubber carefully manufactured have all the . Definition An insulator material, usually a non metal, which the electrons are very firmly bound the nucleus and, therefore, will not allow heat elec- tricity pass through it. All materials are made atoms and electrons. They are non-magnetic and resist rusting. 4. Definition Thermoplastic polymers These may be repeatedly warmed and cooled with- out appreciable changes occurring in the properties the material. Cast iron, wrought iron and steel are all ferrous metals. Definition Ferrous word used describe all metals which the main constituent is iron. Definition Alloy alloy mixture two or more metals. Brass alloy cop- per and zinc, usually the ratio 70–30% 60–40%. These electrons can easily become ‘free electrons’ which allows heat and electricity pass easily through the material