Explain the use of following tools in carrying out electrical wiring installation: (i) Nose pliers (ii) Test lamps (iii) Crimping tools (iv) Cutter.
General Introduction
In electrical wiring, using the correct tool for the job is not just about efficiency; it is a fundamental requirement for safety and the quality of the finished installation. A poor connection or a damaged wire can lead to system failures, fire hazards, or electric shock. The following tools are staples in any electrician's toolkit.
(i) Nose Pliers (or Long-Nose Pliers)
Also Known As: Needle-nose pliers, pointy-nose pliers.
Primary Use:
Nose pliers are designed for precision work, especially for gripping, bending, and manipulating wires and small components in tight or hard-to-reach spaces where fingers or larger tools cannot fit.
Specific Applications in Electrical Wiring:
Forming Wire Loops: Their fine, tapered jaws are perfect for bending the end of a solid conductor into a neat hook or loop, which is necessary for securely attaching it to the screw terminals on outlets, switches, and other devices.
Positioning Wires: They are used to guide and position wires inside crowded junction boxes, electrical panels, or conduits.
Holding Small Components: They can securely grip small nuts, screws, or washers when starting to thread them or when placing them in a confined area.
Straightening Bent Wires: If a conductor gets bent or kinked, nose pliers can be used to carefully straighten it out before termination.
Minor Wire Cutting: Most nose pliers have a small cutting edge at the base of the jaws, which can be used to snip small-gauge wires, although a dedicated cutter is better for a clean cut.
Importance: They provide the fine control and reach needed for detailed and professional-looking wiring terminations.
Safety Note: Always use nose pliers with insulated handles rated for the voltage you are working with. This provides a layer of protection against accidental electric shock if the tool comes into contact with a live part.
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(ii) Test Lamps (or Voltage Testers)
Also Known As: Voltage indicator, neon tester, "Wiggy" (a specific brand).
Primary Use:
A test lamp is a critical safety device used to verify the presence or absence of AC voltage in a circuit, wire, or device. Its primary function is to confirm that a circuit is "dead" (de-energized) before any work begins.
Specific Applications in Electrical Wiring:
Safety Verification: Before touching any wires or terminals, an electrician uses a test lamp to confirm that the power has been successfully turned off at the circuit breaker or fuse box. This is the single most important step to prevent electric shock.
Identifying Live Wires: It can be used to identify which wire in a cable or box is the "live" or "hot" conductor. By touching one probe to the wire and the other to a known neutral or earth/ground point, the lamp will light up if voltage is present.
Basic Fault Finding: It can help diagnose simple problems, such as a faulty switch or a blown fuse, by checking for voltage at different points along a circuit.
The "Test-Live-Test-Dead-Test" Procedure:
A professional electrician always follows this safety rule:
Test the tester on a known Live source to ensure it's working.
Test the circuit you intend to work on to confirm it is Dead.
Test the tester on the known Live source again to ensure the tester didn't fail during the process.
Importance: This is a non-negotiable safety tool. Never assume a circuit is off; always test it.
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(iii) Crimping Tools
Primary Use:
A crimping tool is used to create a secure, solderless connection by joining a wire to a terminal (like a ring, spade, or fork terminal) or by splicing two wires together using a butt connector.
Specific Applications in Electrical Wiring:
Attaching Terminals: When connecting a stranded wire to a screw terminal block (common in appliances, control panels, and vehicle wiring), a crimp-on terminal is used. The crimping tool deforms the barrel of the terminal, compressing it tightly onto the stripped wire.
Splicing Wires: Butt splices are used to join two wires end-to-end. The crimper secures the wire inside each end of the splice connector.
Creating Insulated Connections: Many terminals are insulated. The crimping tool often has a dual die that crimps both the metal conductor and the plastic insulation grip simultaneously, providing strain relief and a more robust connection.
How it Works:
The tool has specially shaped jaws (dies) that match the size and type of the terminal. When squeezed, the jaws apply precise pressure to deform the terminal barrel in a specific way, creating a cold weld between the wire and the terminal.
Importance: A proper crimp provides a connection that is both mechanically strong (won't pull apart) and electrically sound (low resistance). A poor crimp can lead to overheating, intermittent connections, and is a serious fire hazard.
Safety Note: Always use the correct die on the tool for the specific size (wire gauge) of the terminal and wire. Using the wrong size will result in a failed or unsafe connection.
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(iv) Cutter (or Side Cutters)
Also Known As: Side-cutting pliers, diagonal cutters.
Primary Use:
A cutter is used for cleanly and efficiently cutting electrical wires and cables to the desired length.
Specific Applications in Electrical Wiring:
Cutting Wires to Length: Its primary job is to sever copper or aluminum conductors. The hardened, angled jaws are designed to make a clean, square cut.
Trimming Cable Sheathing: It can be used to carefully trim away the outer plastic jacket (sheathing) of a multi-conductor cable like Romex or Twin & Earth, exposing the insulated wires inside.
Stripping Insulation (in a pinch): While a dedicated wire stripper is the best tool for removing insulation, skilled electricians can use the very tip of a cutter to gently score and pull off insulation without nicking the conductor. However, this requires practice to avoid damaging the wire.
Importance: A clean cut is essential for making a good connection. A frayed or mangled wire end is difficult to insert into a terminal and can result in a poor electrical connection. The leverage provided by the handles makes cutting through even thick wires easy.
Safety Note:
Always wear safety glasses when cutting wires, as small pieces of metal can fly off.
Use cutters with insulated handles for protection against shock.
Never use cutters to cut a live circuit. This can cause a dangerous arc flash, damage the tool, and result in severe injury.
Do not use them to cut steel wire or screws, as this will damage the cutting edges.