New book information sheet ISBN author 978-7-12104722-0 Yu Yan, Guodi Practical training and assessment guidance of maintenance electrician skills (junior, intermediate, senior) Title Jin Author unit Hangzhou Xiaoshan Vocational School No.1 Secondary Sample seal (10 pages) Project I basic operation skills of electrician Task 1 wire cutting, connection and insulation restoration Task presentation Be able to identify and use common electrical tools such as electric knife, sharp nose pliers and wire stripping pliers; Know common conductive materials and insulation recovery materials; It can cut and connect wires, and recover the insulation of wires. Knowledge link ● knowledge link 1 use of wire connection tools The common tools for wire connection are electrician knife, sharp nose pliers and wire stripping pliers. See Table 1-1 for their substance and use. Table 1-1 materials and use of electrician knife, sharp nose pliers and wire stripping pliers Name Electric knife Needle nose pliers Wire stripper Physica l figure Use diagra m Key Electrical knife is a Pointed nose pliers Wire stripper is used points tool used to cut the are commonly used to to exploit the insulation of use insulating clamp and cut electrical layer of small diameter equipment wire.Pay layer of electrical materials.When pay attention operation using, to with (such as to wires).When using, pay select different cutting the attention edges of wire stripper the pointed that nose the pliers blade facing outward; cannot be used as a when cutting the wire knocking tool; protect sheath, the insulated pipe of the attention blade should be placed flat to the tong handle avoid cutting the wire avoid core; after using, fold caused by bumping electric to shock according to wire diameters different the blade into the handle in time to avoid damage to the blade or personal injury ● knowledge link 2 common conductive materials The substance that can pass through the current is called the conductive material. Its main purpose is to transport and transfer the current.All kinds of metal materials are conductive materials, but not all metals can be used as ideal conductive materials.As conductive materials, copper and aluminum are the most widely used ones, which should be considered from two aspects: technical performance (good conductivity, certain mechanical strength, not easy to oxidize and corrode) and economic performance (low price). Wire, also known as wire, is an electrical material used to transmit electric energy.Common conductors include bare conductor, insulated conductor, power cable and electromagnetic wire, etc. ● knowledge link 3 common insulation restoration materials The material composed of materials with resistivity greater than 107 Ω? M is called insulating material.The main function of insulating materials is to isolate the electrified body from the uncharged body, to isolate the conductors with different potentials, to ensure the current flow direction or personal safety. In some cases, they also play the role of supporting, fixing, arc extinguishing, corona prevention and moisture prevention.Insulating materials are widely used in power system, such as electrical appliances, motor soleplate, base, shell and winding insulation, conductor insulation protection layer, insulator, etc.As shown in Figure 1-1, it is the most widely used and most used electrical tape.Figure 1-1 electrical tape ● connection requirements of knowledge link 4 conductor (1) reliable connection.The connector has firm connection, good contact, small resistance and good stability.The connector resistance is not greater than the resistance of the same length of wire. (2) sufficient strength.The mechanical strength of the joint shall not be less than 80% of the mechanical strength of the conductor. (3) beautiful joint.The joint is standard and beautiful as a whole. (4) corrosion resistance.For the connected joints, electrochemical corrosion shall be prevented.For the connection of copper and aluminum conductor, copper aluminum transition shall be adopted, such as copper aluminum joint. (5) good insulation performance.The insulation strength of the joint shall be the same as that of the conductor. Operation practice ● make a cutting wire, connecting wire and insulation recovery Wire connection includes the basic steps of cutting wire insulation layer, connecting wire and insulation recovery. Let'

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