Basic Electrical Installation Work

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These electrons can easily become ‘free electrons’ which allows heat and electricity pass easily through the material. Thermosetting polymers Once heated and formed, products made from thermosetting polymers are fixed rigidly. Copper, aluminium, tin, lead, zinc and brass are examples non-ferrous metals. Most corrosion takes place when metal contact with moisture (see also mild steel and zinc). 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. Non-ferrous Metals which not contain iron are called non-ferrous. Definition Ferrous word used describe all metals which the main constituent is iron. Definition Thermoplastic polymers These may be repeatedly warmed and cooled with- out appreciable changes occurring in the properties the material. It good insulator, but degrades and becomes brittle when exposed to sunlight. Brass alloy cop- per and zinc, usually the ratio 70–30% 60–40%. Ferrous metals have magnetic properties. 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.Basic Electrical Installation Work 100 Properties conductors and insulators In Fig. Synthetic rubber manufactured, opposed being produced natu- rally. Definition Alloy alloy mixture two or more metals. They are non-magnetic and resist rusting. Alloy alloy mixture two more metals. Synthetic artificial rubber carefully manufactured have all the . Plug tops, socket outlets and switch plates are made from this material. Definition Corrosion The destruction metal by chemical action. They are good insulators, but give off toxic fumes when burned. Let now define the terms and properties some the materials used in the electrotechnical industry. A conductor material, usually metal, which the electrons are loosely bound the central nucleus. 4.1 the last chapter looked the atomic structure materials. The word ‘ferrous’ comes from the Latin word ferrum meaning iron. Corrosion The destruction metal chemical action. Rubber tough elastic substance made from the sap tropical plants. Polyvinylchloride (PVC) used for cable insulation thermo- plastic polymer. Definition Non-ferrous Metals which not con- tain iron are called non-ferrous. Ferrous word used describe all metals which the main constituent is iron. 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. Thermoplastic polymers These may repeatedly warmed and cooled without appreciable changes occurring the properties the 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. These electrons can easily become ‘free electrons’ which allows heat and electricity pass easily through the material. All materials are made atoms and electrons. Cast iron, wrought iron and steel are all ferrous metals. Definition A conductor material, usually a metal, which the electrons are loosely bound the central nucleus. Definition Polyvinylchloride (PVC) used for cable insulation thermoplastic polymer