Electrical machine control systems require precise assembly using specialized tools, equipment, and materials to ensure optimal performance and safety. This chapter addresses the fundamental components and instruments necessary for assembling and maintaining electrical machines, focusing on the practical realities faced by electronics engineers in Kenya. Proper identification and use of these tools and materials reduce faults, enhance reliability, and comply with industry standards. The discussion integrates examples from sectors such as bottling plants, printing works, cold stores, and apartment blocks where electrical machine control systems are critical.

3.1 Identification of Tools and Materials

In electrical machine control work, identifying the correct tools and materials is essential for accuracy, safety and efficiency. A control installation draws on many items, from cutting tools and measuring instruments to cables, conduits and trunking, and each is chosen for the task and for the place where it will be used. A technician who knows the name, use and limits of each item can prepare a panel or a cable run without delays, wrong substitutions or damaged parts. This topic names and describes the tools, equipment and materials. How they are gathered and checked for a job is covered in Assemble Tools, Equipment and Materials, and how they are counted and stocked in Inventory Management.

3.1.1 Cutting Tools

Cutting tools are essential for shaping, trimming and preparing materials such as wires, cables and conduit. Precise cutting gives clean edges that make better electrical connections and reduce the risk of short circuits and mechanical failure.

Types of Cutting Tools Used in Electrical Work

• Wire strippers: designed to remove insulation from electrical wires without damaging the conductor. Their calibrated notches fit different conductor sizes, which is essential when preparing control cables in a panel workshop.

Manual wire strippers with yellow handles (Source: Wikimedia Commons)

• Diagonal cutters: also known as side cutters, these cut wires flush to a surface and are useful in tight spaces such as the wiring channels of a control panel.
• Cable cutters: larger and more robust, they are used for thick cables, for example the supply cables of a motor control centre or a generator changeover panel. They are meant for copper and aluminium conductors, not for the hardened steel wires of cable armour.

orange-handled cable cutters tool (Source: Wikimedia Commons)

• Hacksaws: used to cut metal conduit and trunking to length. Their fine teeth give smooth cuts, which are essential for neat installations.

A metal hacksaw with an orange blade (Source: Wikimedia Commons)

• Utility knives: used to trim insulation and sheathing on cables, particularly multicore cables. The cut is made away from the body and the blade is retracted after use.

Electric utility knife with blade exposed (Source: Wikimedia Commons)

Material Compatibility and Cutting Efficiency

• Cutting tools are selected for the material, whether copper, aluminium or plastic insulation, to avoid damage to the tool or the work.
• A hacksaw used on plastic conduit needs a fine-toothed blade, so that the plastic is cut cleanly and does not crack.
• Good maintenance, such as sharpening and cleaning blades, improves cutting precision and tool life.
• Ergonomic handles reduce operator fatigue during repetitive cutting in large installations.
• Rust-resistant cutting tools last longer in damp or coastal conditions.

Safety Considerations When Using Cutting Tools

• Wear protective gloves and safety glasses to prevent injury from wire fragments and sharp edges.
• Inspect tools for damage before use, because a dull blade is more likely to slip.
• Cut on a stable surface so that control and accuracy are maintained.
• Dispose of cut-off pieces properly, because loose strands and offcuts are a hazard in a busy workshop.
• Train users in the correct cutting angles and force, which reduces tool damage and strain on the operator.

Maintenance and Storage of Cutting Tools

• Clean tools regularly, because debris causes rust and impairs function.
• Lubricate the moving parts of tools such as wire strippers so that they keep working smoothly.
• Store tools in dry, organised toolboxes to prevent damage and loss.
• Label tools and keep a tool register, so that every tool can be accounted for.
• Sharpen or replace blades periodically so that each cut takes less time.

3.1.2 Measuring Tools

Measuring tools let the technician check that components and assemblies meet the required specifications, which is critical for system reliability and performance. Accurate measurement affects everything from cable length to control panel dimensions.

Types of Measuring Tools in Electrical Machine Control

• Tape measures: flexible and retractable, ideal for measuring conduit runs and cable trays.

Blue and orange 3m tape measure (Source: Wikimedia Commons)

• Vernier calipers: give precise measurements of small components such as terminal screws and sensor housings.
• Rulers and scales: used for quick, less precise measurements during preliminary layout work, for example when planning the position of equipment on a mounting plate.
• Feeler gauges: measure small gaps or clearances, such as the gap between the faces of a motor shaft coupling or the contact gap of a relay.

Set of feeler gauges fanned open (Source: Wikimedia Commons)

Accuracy and Calibration of Measuring Tools

• Calibration against known standards ensures measurement accuracy, and it is a requirement wherever results must be traceable, for example for instruments used in testing and certification.
• Vernier calipers are zeroed before each use to avoid systematic errors.
• The hook end of a tape measure can loosen or bend, and a worn tape gives wrong readings, so the tape is checked against a known length from time to time.
• Temperature affects the dimensions of materials and the readings of measuring tools.
• Calibration records are kept as part of quality control.

Application of Measuring Tools in Assembly and Maintenance

• Measuring conduit lengths before cutting reduces material waste.
• Feeler gauges check alignment and clearances in motor shaft couplings.
• Tape measures set out the distances of cable runs, so that the cable and conduit quantities can be ordered correctly.
• Vernier calipers verify the thickness of insulating sheet and other materials used in control panels.
• Rulers assist in marking drill points on mounting plates.

Care and Handling of Measuring Tools

• Store tools in protective cases to prevent damage to delicate parts such as caliper jaws.
• Avoid dropping or rough handling, which can misalign measuring scales.
• Clean tools after use to remove dirt or conductive dust that could affect readings.
• Retract tape measures fully to avoid bending or kinks.
• Use each tool only for its intended purpose, which prolongs its life.

3.1.3 Measuring Equipment

Measuring equipment refers to the more advanced instruments that give the electrical and mechanical readings needed to diagnose and verify the performance of electrical machines. These devices are indispensable in troubleshooting and commissioning.

Common Measuring Equipment in Electrical Machine Controls

Selection Criteria for Measuring Equipment

• Accuracy and resolution suitable for the expected measurement range.
• Portability for field use, for example when a technician moves between machines on a large site.
• Durability to withstand harsh conditions, including dust and moisture in agro-processing and other plants.
• A safety category rating suited to the circuit: an instrument used on a 415 V panel should carry a CAT III rating, and CAT IV is used where the supply enters the building.
• Ease of use and the availability of local calibration services.

Practical Applications in Field and Workshop

• An insulation tester is used before a control panel installation is energised, which reduces the risk of electrical faults.
• An oscilloscope lets a technician analyse control signals in real time.
• A clamp meter allows a quick current measurement on a live circuit without a shutdown, as when the load currents of the motors of a conveyor line are compared.
• A digital multimeter provides the essential readings during preventive maintenance.
• A tachometer verifies motor speed settings when an automated conveyor is commissioned.

Maintenance and Calibration of Measuring Equipment

• Regular calibration against standards that can be traced to a national standards body, such as the Kenya Bureau of Standards (KEBS), keeps readings accurate.
• Store equipment in protective cases to prevent mechanical damage.
• Check batteries and replace them when needed, because a low battery gives wrong readings in the field.
• Clean connectors and probes so that contact stays good and reliable.
• Document calibration and maintenance schedules to support audit and quality assurance.

3.1.4 Cables and Conductors

Cables carry power and signals between the parts of a control system. A cable is a conductor or group of conductors with insulation, and often a sheath, armour or screen, and the type chosen depends on the circuit and the place it runs through.

Types of Cables Commonly Used

• Twin and earth cable: widely used for the fixed wiring of lighting and socket circuits in offices, workshops and homes.
• Armoured cable: provides mechanical protection with a layer of steel wire or tape, and is suitable for installations in industrial environments such as manufacturing plants.

Various types of armoured cable (Source: Wikimedia Commons)

• Coaxial cable: used to carry radio frequency and video signals, as in antenna and CCTV connections.
• Control cable: designed for control circuits, often shielded to prevent interference, and essential in automation setups.
• Flexible cable: used where there is frequent movement or vibration, such as on portable machines and moving parts of equipment.

Electrical and Mechanical Characteristics

• Conductors are mainly copper or aluminium: copper conducts better, but costs more.
• Insulation materials such as PVC and XLPE differ in temperature rating and flexibility.
• The cross-sectional area of the conductor decides the current-carrying capacity and the voltage drop.
• Mechanical strength and armouring protect cables from physical damage in harsh surroundings such as farms and workshops.
• Shielding reduces electromagnetic interference and improves signal quality in sensitive control circuits.

Installation Considerations and Standards

• Cables are sized for the load current, the length of the run and the way they are installed, using the current-rating tables of the IEE (IET) Wiring Regulations, so that they do not overheat.
• Proper routing avoids sharp bends and mechanical stress, which extends the life of the cable.
• Power and control cables are kept apart, because separation reduces noise interference.
• Installation complies with the Energy Act, 2019 and the wiring regulations, which makes it legal and safe.
• Cable trays and conduits protect cables and make maintenance easier.

Inspection and Testing of Cables

• Inspect visually for cuts, abrasions or damaged insulation before installation.
• Continuity tests after installation verify the integrity of each conductor.
• Insulation resistance testing detects moisture or insulation breakdown.
• Thermal imaging of a loaded installation can reveal hot spots at terminations.
• Documented test results support maintenance records and fault diagnosis.

3.1.5 Crimping Tool

Crimping tools are specialised tools used to attach connectors to cables, so that the connection is secure and of low resistance. Proper crimping is crucial in control systems for signal integrity and mechanical stability.

Types and Features of Crimping Tools

• A ratchet mechanism ensures full compression before release, which improves crimp quality.
• Die sets must match the terminal types (ring, spade and butt connectors) and the wire gauges.
• Hydraulic tools give uniform pressure, which is essential for large cables such as the lugs of a generator or transformer connection.
• Manual tools offer portability and precision for small-scale tasks.
• Insulated handles improve operator safety during use.

Crimping Process and Best Practices

1. Select the correct die size for the cable and the connector, to avoid loose or damaged crimps.
2. Strip the insulation to the right length before inserting the conductor into the terminal.
3. Position the connector correctly in the jaws of the crimping tool.
4. Apply steady pressure until the ratchet releases or the tool indicates completion.
5. Inspect the crimp visually: the insulation must not be crushed and the conductor strands must not be cut.
6. Pull-test the crimp to check its mechanical strength.

Maintenance and Storage of Crimping Tools

• Clean the dies regularly to prevent build-up that can affect crimp quality.
• Lubricate moving parts so that the tool works smoothly.
• Store tools in protective cases to avoid damage and contamination.
• Check calibration periodically so that the crimping force stays consistent.
• Train users in correct handling, which reduces damage and improves connection reliability.

3.1.6 Conduits

Conduits are protective tubes that house electrical cables and shield them from physical damage and environmental hazards. They are widely used in industrial installations to enhance safety and system life.

Types of Conduits and Their Applications

• PVC conduits: lightweight and resistant to corrosion, suitable for indoor installations in offices and workshops.
• Metallic conduits (thin-wall and heavy-gauge steel): give strong mechanical protection and are preferred in industrial and outdoor settings.
• Flexible conduits: bend around obstacles, and are used for the short final connection to a motor or a machine that vibrates.
• Liquid-tight conduits: protect cables from moisture, oil and coolant, which makes them essential in wet areas such as washdown zones.
• Surface and embedded conduits: the installation method affects the choice: surface-mounted conduits are easier to alter, while embedded conduits are hidden in the wall or floor.

Selection Criteria for Conduits

• Environmental exposure, including moisture, chemicals and mechanical stress.
• Compliance with the Energy Act, 2019 and the IEE (IET) Wiring Regulations.
• Compatibility with the cable types and the installation methods.
• A balance between cost and the durability required.
• Ease of installation and of access for future maintenance.

Installation Practices and Safety

• Conduits are fixed firmly at regular intervals so that they do not sag.
• Bends are smooth, so that cables are not damaged when they are pulled in.
• Joints and fittings must keep the mechanical and environmental protection.
• Earth continuity is maintained in metallic conduit installations.
• Proper sealing keeps out dust and moisture, which matters in dusty or wet areas.

3.1.7 Trunking

Trunking systems organise and protect electrical wiring in commercial and industrial buildings. They give a neat, accessible way of managing cables, especially in complex control systems.

Types of Trunking Systems

• PVC trunking: non-conductive and resistant to corrosion, suitable for indoor use in offices and workshops.
• Metal trunking: offers mechanical protection and some screening against electromagnetic interference, and is used where cables need strong protection, such as in a control room. Metal trunking is earthed and bonded across its joints.
• Surface-mounted trunking: easy to reach for maintenance and upgrades.
• Flush-mounted trunking: concealed, for a neat appearance in finished areas.
• Modular trunking: can be customised and extended, which suits systems that grow.

Benefits of Using Trunking

• Organised cable routing reduces clutter and improves safety.
• It gives physical protection against impact and abrasion.
• It makes cables easy to identify and reach for maintenance.
• It supports the separation of power and data cables, with dividers inside the trunking, to minimise interference.
• It improves the appearance of the installation.

Installation Considerations

• Size the trunking for the present and future cable volumes.
• Fix it securely to walls or ceilings so that it does not move.
• Use the proper accessories, such as bends, tees and couplers.
• Comply with fire safety rules, including flame-retardant materials and fire barriers where trunking passes through walls and floors.
• Plan the separation of cables and the earthing where they are needed.

3.1.8 Consumables

Consumables are items that are used up or worn out during installation and maintenance, and are replaced regularly: connectors, tapes and adhesives are typical. Their quality directly affects system reliability and safety. The curriculum lists the small hand tools of the electrician's kit under this heading. They are tools, not consumables, but each has a part that wears out or gets lost (a blade, die, bit, spring or tape hook), so they are stocked and replaced together with the consumables.

Common Consumables in Electrical Assembly

• Insulation tape: used for insulating and bundling wires, and must be rated for the voltage and temperature.

Rolls of insulation tape for electrical use (Source: Wikimedia Commons)

• Cable ties: secure cables in place and prevent movement and strain.

Various coloured cable ties on white surface (Source: Wikimedia Commons)

• Heat shrink tubing: gives insulation and environmental protection to splices and terminals.

Various coloured heat shrink tubing pieces (Source: Wikimedia Commons)

• Connectors and terminals: make secure electrical connections, and must match the cable sizes and types.
• Solder and flux: used in circuit assembly for permanent electrical joints.

Importance of Quality Consumables

• Good insulation tape prevents short circuits and fire hazards in control panels.
• Durable cable ties keep cables organised under vibration, as on agricultural machinery or a conveyor.
• Heat shrink tubing protects connections against moisture, which extends their life, for example on cables near the coast.
• Correctly rated connectors ensure low resistance and mechanical stability.
• Suitable solder and flux prevent cold joints, which are essential in precision electronics work.

Storage and Handling of Consumables

• Store consumables in a dry, dust-free place so that they keep their properties.
• Keep solder away from moisture, which can degrade the flux.
• Keep insulation tapes in sealed packaging to retain the adhesive.
• Organise consumables by type and size for quick retrieval during maintenance.
• Monitor stock levels to prevent shortages during critical repair work.

Environmental and Safety Considerations

• Dispose of used solder and flux residues according to environmental regulations.
• Use non-toxic, flame-retardant tapes and materials to comply with safety standards.
• Do not over-tighten cable ties, because this can damage insulation and conductors.
• Select consumables that meet the safety standards of the Kenya Bureau of Standards (KEBS) where they apply.
• Train staff in correct use and disposal to minimise hazards in the workplace.

3.1.8.1 Cable strippers

A cable stripper removes the insulation from a conductor without cutting the strands. For control wiring the notch or setting must match the conductor size: a notch that is too small cuts strands and one that is too large leaves insulation on the conductor. Chipped notches and dull blades damage conductors, so a worn stripper or its blade is replaced. For repeated work an automatic stripper saves time and gives a more even strip length. See Cutting Tools for the types.

3.1.8.2 Pliers

Pliers grip, bend and cut. Combination pliers do general gripping, bending and cutting, long-nose pliers place conductors in tight terminals and bends, and side cutters trim conductor ends. Insulated pliers have handles tested to a stated voltage, often marked 1 000 V, and the marking is a guide to the handle insulation, not permission to work on live equipment. A cracked or loose handle, or jaws that no longer meet, means the tool is withdrawn.

3.1.8.3 Screwdrivers

Screwdrivers drive the terminal and mounting screws of control equipment. Slotted, cross-head (Phillips) and Pozidriv blades are used, and the blade must fit the screw head exactly, with a tip as wide as the slot of a terminal screw, otherwise the screw head is damaged or the screwdriver slips into neighbouring terminals. Insulated shanks reduce the risk of contact with live parts, and a torque screwdriver tightens terminals to the maker's value. A rounded or chipped tip slips from the screw and is replaced.

3.1.8.4 Hammers

A claw hammer drives nails and clips and pulls them out, a club hammer drives chisels and wall plugs, and a ball-pein hammer shapes and rivets metal. A soft-faced hammer, with a rubber or nylon face, taps enclosures and panels without marking them. The head must be fixed firmly to a sound handle, and a head that is loose or a face that has mushroomed is a danger, so the hammer is withdrawn.

3.1.8.5 Chisels

A cold chisel cuts metal and masonry, and a plugging chisel or bolster chisel is used to cut chases in walls and floors for conduit. The chisel is struck with a club hammer, with safety glasses worn. The head of a chisel spreads out into a mushroom after repeated blows, and the burr can fly off, so it is ground off. A blunt edge is reground to its angle, and a chisel with a cracked head is scrapped.

3.1.8.6 Allen keys

An Allen key, or hex key, is an L-shaped bar with a hexagonal end. It fits socket head screws and set screws, such as the grub screws that hold a coupling or a pulley on a motor shaft and the screws of drive and sensor mounts. Sizes are measured across the flats in millimetres and are sold in sets, and the key must fit the socket fully: a key that is too small rounds the corners of the socket. A key with rounded corners slips and strips the screw, and it is replaced.

3.1.8.7 Electrician's knives

An electrician's knife has a short blade, often hooked or with a blade guard, for removing the outer sheath of cables. The cut is made away from the body and only through the sheath: pressing too hard cuts the insulation of the cores below. A dull blade needs more force and slips, so blades are changed or the knife is sharpened. A folding knife is closed and a fixed blade is kept in its sheath after use. See Cutting Tools for the other cutting tools.

3.1.8.8 Crimping tools

Crimping tools fix terminals, lugs and ferrules to conductors, and the types are described under Crimping Tool. The terminals and ferrules are the consumable part, bought in boxes by size and colour. The dies of the tool wear with use, and when the crimps start to look uneven or pull out in a pull test the dies or the tool are replaced. The tool, the die and the terminal must all be matched to one another.

3.1.8.9 Bending springs

A bending spring is a coil spring that is slid into a PVC conduit before it is bent. It supports the wall of the conduit from inside so that the tube bends smoothly without kinking or flattening. The spring must be made for the size of the conduit, and the conduit is bent over the knee or a former to at least the minimum radius the conduit allows. The spring is then turned and withdrawn, with a cord tied to its end so that it can be retrieved. A rusted or stretched spring is discarded.

3.1.8.10 Steel tapes

A steel tape is a flexible steel measuring blade wound into a case, marked in millimetres and centimetres, with a locking button. It measures the lengths of cable runs and conduits and the positions of mounting points. The loose hook at the end moves by its own thickness so that inside and outside measurements are both correct, and a bent hook or a kinked blade gives wrong readings. Steel conducts, so a steel tape is never used near exposed live conductors: a fibreglass tape is used there instead.

3.1.8.11 Draw wires

A draw wire, also called a fish tape, is a long flat spring-steel strip, or a nylon or fibreglass rod, that is pushed through conduit or trunking to pull cables through. The cable ends are fixed to its hook or loop, and cable pulling compound reduces friction in long runs. The pull must stay within the cable's pulling limits. Kinks, rust and a broken hook make a draw wire unreliable, and a nylon rod is chosen where there may be live conductors nearby. A draw wire may be left in a conduit when empty, ready for a later cable.

3.1.8.12 Hacksaws

A hacksaw has a frame holding a replaceable, tensioned blade, and the blades are the consumable part. The teeth point away from the handle so that the saw cuts on the forward stroke, and the blade is chosen so that at least three teeth are in the material at any time: a fine-toothed blade is used for thin-walled conduit and trunking. A blade that is dull or has lost teeth is replaced, and the cut ends are deburred so that the edges do not damage cable. See Cutting Tools for the uses.

3.1.8.13 Drills

A drill makes the holes for mounting plates, saddles and plugs, and for cable entries into enclosures. Hand drills, mains drills and battery-powered drills are used, and the bits are the consumable part. A twist bit made of high-speed steel drills metal, and a masonry bit with a hard tip, used with hammer action, drills walls. The bit size is chosen to suit the plug or screw, a slow speed is used for large holes in metal, and the work is clamped. A bit that is blunt or burnt is replaced. A mains drill is used with a residual current device, and safety glasses are worn.

3.1.9 Equipment

Equipment means the instruments and powered devices used to test, measure and configure a control system. Unlike consumables, equipment is not used up: it is kept in the tool store, calibrated, charged and updated. The measuring instruments of this kind are described under Measuring Equipment. Two items that are placed in the kit of every control system installer are described here.

3.1.9.1 Multimeters

A digital multimeter measures AC and DC voltage, current and resistance, and has a continuity setting that beeps when a circuit is complete. In control work it is used to confirm the supply (240 V single phase or 415 V three phase) at the incoming terminals, to prove that a circuit is dead before work begins and to check the continuity of wiring before the panel is energised. The meter is tested on a known live source before and after proving a circuit dead. The leads are moved to the current socket only to measure current in series, and are returned afterwards, because a meter left on a current range across a supply blows its fuse or causes a short circuit.

Digital multimeter with probes (Source: Wikimedia Commons)

3.1.9.2 Computer

A laptop computer is part of the kit of a control system installer. It runs the programming software for controllers, the parameter software of drives, and the configuration software for operator panels, and it connects to them with the cable the maker specifies, by USB, serial or Ethernet. It is used to load and test a program, to save a copy of the program before any change, to read manufacturer's manuals and to write test and commissioning records. The software must suit the operating system and the controller version, licences must be valid, and the battery must be charged. The computer is kept free of dust and protected from knocks in the field.

3.1.10 Materials

Materials are the items that stay in the finished installation: unlike tools they are not taken away, and unlike consumables they are not used up in the work. They are ordered from the quantities taken from the drawings and the site measurements, with a small allowance for waste, and they are checked against the order when they arrive.

3.1.10.1 Cables

The types of cable and their characteristics are described under Cables and Conductors. As materials, cables are ordered by type, core count, conductor size and length, and are supplied on drums. The length is taken from the measured cable route, with extra for the bends and terminations at each end. The drum label is checked on delivery, damaged drums and cut ends are inspected, and the drum number is recorded so that a fault can be traced to its batch.

3.1.10.2 Fittings

Fittings are the parts that join, fix and enter the cables and conduit. They include cable glands that enter enclosures and grip the armour, lugs and ferrules that terminate conductors, conduit couplings, bends and saddles, and junction boxes. Each fitting must match the size and the thread of what it connects, as when an M20 or M25 gland fits an enclosure entry, and be rated for the protection the place needs. A mismatched fitting leaves a gap for dust and moisture.

3.1.10.3 Accessories

Accessories are the small parts that complete and finish the installation. For a control panel they include DIN rail and end clamps, terminal blocks and their jumpers, cable markers and labels, duct covers, blanking plates and earthing studs. They are chosen to match the panel components and are bought with spares, because a shortage of one small item can stop a whole installation.

Chapter Summary

This chapter focused on the identification of essential tools and materials required for electrical machine control systems, beginning with cutting tools used for shaping and preparing components. It then covered measuring tools and equipment vital for ensuring precision and accuracy during assembly. The discussion included various types of cables and conductors, highlighting their roles in electrical connections. The chapter also examined the function and importance of the crimping tool in securing cable terminations. Conduits and trunking were described as protective enclosures for cables, ensuring safety and organization. Attention was given to consumables, which are indispensable for completing electrical installations. Finally, the chapter addressed the procedures for assembling these tools, equipment, and materials effectively, alongside strategies for efficient inventory management to maintain readiness and minimize downtime.