CGLI 2330 Certificate in Electrotechnical Technology Level 2 Inst Tech: Unit 202 – Principles of Electrotechnology
Unit 10 – Hand and Power Tools
Hand & Power Tools Unit Aims By the end of the unit participants should be able to:
State the application and safe use of hand and power tools relative to their a) Strength b) rigidity c) control of movement d) insulation properties hand tools - pliers, cutters, saws, strippers, screwdrivers, hammers, chisels, files, crimping tools, conduit benders, socket sets, spanners, soldering irons, solders and fluxes, riveting tools, measuring tools, levels, testing devices; power tools - drills, saws, grinders, staplers. Syllabus Reference: 2.4.01
State the need for electrically operated tools (110V a.c. or battery operated) to undergo inspection checks prior to and after use. Syllabus Ref: 2.4.02
State the inherent risks of electric shock when using extension leads and electrical tools/equipment Syllabus Reference: 2.4.03
State the need for safe handling and storage of tools, equipment and electrically operated tools Syllabus Reference: 2.4.04
Hand & Power Tools The Electricians Toolbox A basic tool kit, which should be built up by all trainee electricians, would include such items as:
Pin hammer Claw hammer Screwdrivers for slotted head and cross head screws Junior hacksaw Spanners Small spirit level Plumb-bob and line Metric rule Bolster cold-chisel
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Club hammer Knife (not Stanley type) Side cutters Strippers Electrician’s terminal Pliers Small file Frame hack saw Pipe grips
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CGLI 2330 Certificate in Electrotechnical Technology Level 2 Inst Tech: Unit 202 – Principles of Electrotechnology
Unit 10 – Hand and Power Tools As your career progresses you will obviously acquire more tools to meet your needs. You should purchase a secure toolbox to put your own hand tools in. Remember that damaged tools must be repaired or replaced for your own and others’ safety. Tools for testing the cable and specialist items, such as conduit benders, may be provided by your employers. Tools are expensive to replace. Take care of your own and your employer’s tools. Keep them clean and in good condition and it is also a good idea to consider insuring them.
Tools Hacksaws Work to be cut with a hacksaw needs to be held firmly in a vice and the line of cut should be close to, but clear of, the jaws. A hacksaw can be used with either a vertical or a horizontal blade. The blade can be turned by releasing the tension adjusters and rotating the blade support blocks. Cold Chisels and Bolsters When using a cold chisel always ensure that the chisel head is safe to use. Grind away any mushrooming metal remembering to use eye protectors during this process. Files There are many variations of file face for filing away rough edges on such items as trunking or cable tray. A handle should always be fitted to the file before use and the work piece should be held securely in a vice.
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CGLI 2330 Certificate in Electrotechnical Technology Level 2 Inst Tech: Unit 202 – Principles of Electrotechnology
Unit 10 – Hand and Power Tools Drills Drills need to be chosen for their intended use. There are special drills for cutting masonry or hardened steel and a wide variety for general purpose drilling. They should all be stored carefully and kept sharp and ready for use.
Taps and dies For cutting internal threads a tap is used with a tap wrench to turn the tap to cut the thread. When cutting the thread rotate the tap one full turn clockwise then a half turn anticlockwise, this will break off the swarf that has been produced. The use of cutting compound will extend the life of the tools and make cutting threads and holes easier.
Hole saws Hole saws are often used with electric drills but the speed must be kept low to prevent the blade from burning up and cutting compound should be used.
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CGLI 2330 Certificate in Electrotechnical Technology Level 2 Inst Tech: Unit 202 – Principles of Electrotechnology
Unit 10 – Hand and Power Tools Reamers A conduit reamer is a hardened steel cone shaped swarf cutter and the size of the cut hole regulates the depth the reamer is allowed to go. Hole punch A hole punch is only suitable for use on sheet metal. A pilot hole is drilled first and the punch and die assembled on each side of the material to be pierced. The draw bolt is passed through the die and screwed into the punch. The draw bolt is then tightened up with the key-wrench exerting a shearing force on the cutter which pierces the hole.
Power tools So far we have considered hand tools but powered machines are often used such as an electric drill, hacksaw or grinder.
Power on Construction Sites Temporary electrical supplies on construction sites can save many person-hours of labour by providing energy for fixed and portable tools and lighting. However, construction sites are dangerous places and the temporary electrical supplies must be safe. BS7671 Regulation 110.01 tells us that the Regulations apply to temporary electrical installations such as constructions sites. The frequency of inspection of construction sites is increased to every 3 months because of the inherent dangers.
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CGLI 2330 Certificate in Electrotechnical Technology Level 2 Inst Tech: Unit 202 – Principles of Electrotechnology
Unit 10 – Hand and Power Tools The following voltages are recommended for distributing plant and equipment on construction sites: 400 volts, 3-Phase 230 volts, 1-Phase 110 volts, 3-Phase, star point earthed
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110 volts, 1-Phase, centre point earthed
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25 volts, 1-Phase, SELV
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Fixed and moveable equipment, above 3.75 kW. Fixed floodlighting. Reduced low voltage system Portable hand-held tools and local lighting up to 2 kW Small mobile plant, up to 3.75 kW. Reduced low voltage system Portable hand lamps for general use Portable hand-held tools and local lighting up to 2 kW. Portable hand lamps in confined or damp locations.
Portable tools must be fed from a 110 volt socket outlet unit incorporating splash-proof sockets and plugs with a keyway which prevents a tool from one voltage being connected to a socket outlet of a different voltage. The 230/110 volt transformer unit has its secondary centre tapped to earth so that touching a phase and earth will result in a shock not exceeding 55 volts as shown below:
Socket outlets and plugs are also colour-coded for voltage identification as follows: 25 volts 50 volts 110 volts 230 volts 400 volts
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Violet White Yellow Blue Red
For more information see pages 152 to 158 of ‘Electrical Installations Level 2 2330 Technical Certificate’ – revised for the 17th Edition IEE Wiring Regulations (ISBN 978 0 435401 09 2).
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