Electrical installation in electronics engineering demands precise handling of various tools, equipment, and materials. The effective assembly and use of these resources ensure safety, accuracy, and efficiency in installation tasks. In Kenya, electronics engineers working in bottling plants, printing works, cold stores, and manufacturing firms rely on specialized tools to maintain complex systems, making the classification and appropriate use of these tools foundational knowledge.

3.1 Classification of tools

An electrician's tools are grouped by the job they do: cutting, measuring, fixing, joining, testing and special tasks. Grouping them this way makes it easy to build a toolkit for a job, to check that nothing is missing before leaving the workshop, and to keep each class of tool in its own place in the tool bag. A wiring job for a small shop, for example, needs cutting tools to prepare cables, measuring tools to set out conduit runs, fixing tools to mount accessories, and test equipment to prove the finished circuit.

3.1.1 Cutting tools

Cutting tools are used to prepare conduit, trunking, cable and conductors to length and to remove insulation. A cutting tool that is blunt or damaged slips, nicks conductors and injures the user, so it is inspected before every job.

Hacksaw

A hacksaw is a frame with a replaceable, fine-toothed blade used to cut metal conduit, steel trunking, threaded rod and cable tray. Blades are chosen by the number of teeth per 25 mm, so that at least three teeth are in contact with the metal at all times: a finer blade (24 or 32 teeth per 25 mm) suits thin-walled conduit, tube and sheet, and a coarser blade (14 or 18 teeth per 25 mm) suits thick or solid sections such as threaded rod. The blade is fitted with the teeth pointing away from the handle, so that the saw cuts on the forward stroke, and the cut edge is filed smooth (deburred) so that it cannot damage cable insulation inside the conduit.

Stripping knife

A stripping knife has a short, sharp blade, often with a curved or hooked tip, used to remove the outer sheath of a cable and the insulation from conductors. It is always drawn away from the body and at a shallow angle, so that the blade removes the insulation without cutting into the copper. A nicked conductor has a smaller cross-sectional area, heats up under load and may break at the nick later. For this reason a wire stripper with sized notches is preferred on small conductors.

Side cutter

A side cutter (diagonal cutter) is a pair of pliers with angled cutting edges set at the side of the jaws. It cuts cable cores, cable ties and small wire flush to a terminal or a surface. The tool is chosen to match the conductor: a light side cutter is used for small control and signal wires, and a heavier one for conductors of 2.5 mm² and larger. Cutting hardened wire such as steel armour with a light cutter chips the edges.

Pliers

Combination pliers grip, bend, twist and cut conductors. Long-nose (snipe-nose) pliers reach into switch boxes and help form neat terminal loops in small conductors. Electricians use pliers with insulated handles, and the handles are checked for cracks before use. Insulated handles are a second line of protection only: the circuit is still isolated first, and the pliers are never used as a hammer or to turn a nut that needs a spanner.

3.1.2 Measuring tools

Measuring tools are used to mark out the position of boxes, conduit runs and accessories and to check that the work is square and level. Good setting out reduces the number of bends and joints and makes the finished work neat.

Tape measure

A tape measure is a flexible steel tape in a case, used for lengths of cable, conduit and trunking and for heights of switches and sockets above the floor. A tape of 5 m to 8 m is adequate for room work, and a longer tape is used for runs along walls and ceilings. The hook at the end is slightly loose so that it reads correctly for both inside and outside measurements, and the tape is read at eye level and never stretched round corners.

Try square

A try square has a steel blade fixed at exactly 90° to a stock. It is held against the edge of a board or the corner of a wall to mark a line at right angles for a conduit saddle, a trunking cut or a mounting board. Setting out boxes and trunking with a square keeps horizontal and vertical runs at right angles to each other.

Steel rule

A steel rule is a stiff, graduated strip, usually 300 mm or 600 mm long, with millimetre markings. It is more precise than a tape for short dimensions and is used for marking the length of a conduit cut, the spacing of screw holes and the size of cut-outs in trunking and panels. It also serves as a straight edge for drawing a line.

Spirit level

A spirit level has one or more sealed vials, each holding a bubble in liquid. When the bubble rests between the two marks, the surface is horizontal (or vertical, for the end vials). It is used to level distribution boards, trunking, cable trays and rows of sockets, so that accessories look straight and do not tilt when screwed in place. The level is held on the surface being checked and read from directly in front.

3.1.3 Fixing tools

Fixing tools drive fasteners and secure equipment, boxes, clips and supports to the building structure.

Hammers

A claw hammer drives nails and pulls them out; a club (lump) hammer with a cold chisel is used for chasing small recesses in brick and concrete. For a typical wiring job the hammer drives masonry nails or plugs for cable clips, saddles and light fittings. The head is checked for looseness before use, and goggles are worn when chiselling, because chips fly off masonry.

Screwdrivers

Screwdrivers turn screws on terminals, boxes, accessories and enclosures. The common blade types are flat (slotted), Phillips (cross-head) and Pozidriv. The tip must fit the screw head: a tip that is too small slips and damages the head, and one that is too large cannot seat. Electricians use screwdrivers with insulated shafts and handles, and a small precision set for electronic control equipment. A screwdriver is not used as a chisel, a lever or a circuit tester.

3.1.4 Crimping tool

A crimping tool squeezes a lug, ferrule or connector onto a stripped conductor so that the conductor and the barrel make a gas-tight, low-resistance joint. The tool has jaws shaped for the type of terminal, and ratchet crimpers do not release until the crimp is complete. The jaw die size must match the lug size: a small die gives a loose joint that overheats under load, while a die that is too large crushes the strands. The stripped length matches the barrel, and a gentle pull on the finished joint confirms that the conductor cannot slip out.

3.1.5 Equipment

Equipment is the larger or more specialised apparatus that the electrician uses for testing, machining and holding work.

Multimeter

A multimeter is the electrician's general-purpose meter. A digital multimeter shows voltage, resistance and continuity on one display, and many models also measure current and test diodes. The probes are plugged into the correct sockets and the range or function is set before the probes touch a circuit; resistance is never measured on a live circuit. The meter is checked against a known source from time to time, and calibrated at the interval the maker states, so that its readings stay trustworthy. A meter used on mains circuits should carry a safety category rating suitable for the supply (CAT III is common for distribution boards), and leads should be checked for damage before each job.

Stock and die

A stock and die cuts an external thread on steel conduit or rod. The die is held in the stock (the handle), set to the pipe, and turned with cutting oil applied; the die is backed off a half turn every few turns to clear swarf. The thread is cut long enough to let the coupling or box adaptor seat fully. Threaded steel conduit is used in industrial and workshop wiring, where mechanical protection is required.

Vice

A vice grips work firmly so that both hands are free for cutting, threading or bending. A bench vice is bolted to a solid bench, and a pipe vice has V-shaped jaws that hold a round conduit without crushing it. Soft jaw covers (for example aluminium or fibre) protect threaded ends and finished surfaces. The work is clamped close to the jaws to reduce vibration while cutting.

Insulation resistance meter

An insulation resistance meter (also called an insulation tester) applies a high d.c. voltage between conductors, or between a conductor and earth, and displays the resistance of the insulation in megohms. A low reading shows moisture, damage or contamination in the insulation. The meter is used only on a dead, isolated circuit, in dry conditions and with its leads firmly connected, because the test voltage is high. The test procedure is taught in the chapter on inspecting and testing the installation.

Earth resistance meter

An earth resistance meter measures the resistance between an earth electrode and the general mass of earth. It works with two auxiliary test stakes driven into the ground and a set of leads. The reading is compared with the value that the design requires. The test procedure is taught in the chapter on inspecting and testing the installation.

Clamp meter

A clamp meter has hinged jaws that open and close around one conductor. The current in that conductor induces a signal in the jaws, which the meter reads as amperes without any break in the circuit. It is used to check the load on a feeder or motor circuit while the system runs. The jaws are closed round one conductor only: clamping a whole cable containing line and neutral reads close to zero, because the two currents cancel out. The meter is zeroed (on a d.c. clamp range) before the jaws are closed, as the maker directs, and the jaws are kept clean so that they close fully.

Pipe bending machine

A pipe bending machine forms conduit into bends, offsets and sets with a smooth radius, so that cable can be drawn in without damage. Hand benders suit small-diameter conduit, and hydraulic or geared machines are used for larger sizes. The former (shoe) must match the conduit diameter, and the bend is made in one smooth action to avoid flattening. The bend is marked with a pencil from the measured centre line, and bends are checked against a drawing or template. The guards and the pins of a machine are kept in place, and hands are kept clear of the former while the bend is made.

3.1.6 Others

Several smaller aids make drawing in cable and shaping conduit easier.

Draw wire

A draw wire (fish tape) is a flexible steel or nylon strip fed through a conduit or behind a wall. The cable is attached to its end and pulled back through the run, which makes it possible to draw cables through a long or crowded conduit. The draw wire is pushed in from the end with fewer bends, and cables are attached firmly so that they do not detach in the middle of the run.

Bending spring

A bending spring is a tight coil of steel placed inside a plastic (PVC) conduit before it is bent by hand. It supports the walls of the conduit from the inside so that the bend forms a smooth curve and does not collapse. The spring is slid into place, the conduit is bent over the knee or a former, and the spring is twisted slightly to release it. Springs are matched to the conduit diameter.

Drill

A drill makes holes in wood, metal and masonry for fixing screws, cable entries and boxes. A hammer drill with a masonry bit is used for brick and concrete, and a standard drill with twist bits is used for metal and wood. Cordless drills are convenient on site because they do not need an extension lead, and mains-powered drills are protected by an RCD. The correct bit for the material and the correct speed are chosen, and eye protection is worn.

Chapter Summary

This chapter covered the classification of tools used in electrical installation, including cutting, measuring, fixing, and crimping tools, as well as essential equipment such as multimeters and pipe bending machines. It emphasized the proper use, care, and maintenance of these tools to ensure their longevity and safety during operations. Identification of various materials like cables, consumer control units, switches, sockets, conduits, and screws was discussed to aid accurate selection and application. The chapter also addressed the specifications of tools, equipment, and materials, focusing on factors such as tolerance, make, size, and class to meet technical requirements. Procedures for the reuse and responsible disposal of materials were outlined to promote sustainability and cost efficiency. The preparation and understanding of the bill of quantities were introduced to facilitate project planning and resource allocation. Finally, the importance of listing, assembling, and managing inventory through stock taking and record keeping was highlighted to maintain organized and efficient electrical installation workflows.