Basic Electrical Installation Work

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