Class: Senior Secondary School 1 (SS1 / SSS 1)
Term: Second Term
Week: 5
Age: 15 years
Duration: 45 minutes
Subject: Electrical Installation and Maintenance Work
Curriculum Theme: Technology
Previous Lesson: Surface Wiring: Cable Identification.
Topic: PRACTICAL CLASS ON A POINT CONTROLLED BY A SWITCH
Subject Matter: circuit diagram of a point of light controlled by a switch, practical surface wiring procedure, correct use of clips PVC and nails, safety steps during practical wiring

Specific Objectives

By the end of the lesson, pupils should be able to:

Cognitive Domain:

Identify the components of a light point circuit controlled by a switch.
State the steps for wiring a light point controlled by a switch using surface wiring.
Explain important safety measures to observe during practical electrical wiring.

Affective Domain:

Appreciate the importance of safety practices in all electrical work.
Show willingness to follow correct wiring procedures and safety rules.

Psychomotor Domain:

Sketch the circuit diagram of a light point controlled by a switch.
Wire a simple light point controlled by a switch on a wiring board.
Correctly use clips, PVC, and nails to secure cables during wiring.

Collaborate effectively with peers during practical wiring sessions.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum for Electrical Installation and Maintenance Work.
State Unified Scheme of Work for Senior Secondary Schools.
Electrical Installation and Maintenance Work for Senior Secondary Schools by Engr. M.O. Adebayo and Dr. T.N. Okoro.
https://www.electrical4u.com/circuit-diagrams/
https://www.safetynigeria.com/electrical-safety-tips/

Instructional Materials

The teacher will teach this lesson with the aid of:

Circuit diagram of a point of light controlled by a switch (on chart or drawn on board).
Wiring board.
Cable samples (e.g., 1.5mm² single core cables).
Clips (e.g., PVC saddles), PVC conduit, nails, and a hammer.
Single pole switch.
Bulb holder and a light bulb.
Screwdrivers, pliers, wire stripper.
Testing equipment (e.g., multimeter, test lamp).

Rationale for the Lesson

This lesson enables pupils to gain practical skills in wiring a basic electrical circuit, which is a fundamental aspect of electrical installation. It helps pupils to understand how common household lighting works and teaches them important safety practices for handling electrical components.

Prerequisite/Previous Knowledge

Pupils should have basic knowledge of electrical components such as switches, bulbs, and cables, and understand simple electrical circuit concepts.

Lesson Content/Board Summary

PRACTICAL CLASS ON A POINT CONTROLLED BY A SWITCH

Circuit Diagram of a Point of Light Controlled by a Switch

A circuit diagram is a simplified visual representation of an electrical circuit using standard symbols to show the connection of components.

The circuit for a light point controlled by a switch involves:

A power source (e.g., mains supply).
A single pole switch (to control the flow of current).
A light bulb and its holder.
Connecting cables (Live, Neutral, Earth).

Practical Surface Wiring Procedure

Surface wiring involves installing cables and accessories directly on the surface of a wall or wiring board, often using clips or conduits.

The steps for practical surface wiring of a light point controlled by a switch include:

Planning: Decide the position of the switch, bulb holder, and cable runs.
Marking: Mark the points on the wiring board where components will be fixed and where cables will run.
Fixing Components: Secure the switch and bulb holder to the marked positions.
Cable Routing: Cut cables to the required lengths, allowing for connections.
Stripping Cables: Carefully remove insulation from cable ends for connections, ensuring no damage to the conductor.
Connections: Connect the Live wire to the switch, then from the switch to the bulb holder. Connect the Neutral wire directly to the bulb holder. Connect the Earth wire to appropriate points if required.
Securing Cables: Use clips (e.g., PVC saddles) and nails to secure the cables neatly along the marked routes.
Testing: Perform continuity and insulation resistance tests before applying power.
Power Application: Carefully switch on power and test the light point.

Correct Use of Clips, PVC, and Nails

Proper use of these materials ensures neatness, safety, and durability of the installation.

Clips (e.g., PVC Saddles): Used to hold cables firmly against the surface. They should be spaced evenly (e.g., every 30-40 cm) and not overtightened to avoid damaging the cable insulation.
PVC Conduit: Used to enclose and protect cables, especially where mechanical protection is needed or for a neater finish. Cables are drawn through the conduit.
Nails: Used with clips or saddles to fix them to the wiring board or wall. Nails should be of appropriate length and thickness to provide a secure fixing without piercing the cable.

Safety Steps During Practical Wiring

Observing safety steps is important to prevent electrical shock, fire, and injury.

The following are important safety steps:

Always switch off the main power supply before starting any wiring work.
Use appropriate Personal Protective Equipment (PPE) such as insulated gloves and safety glasses.
Use insulated tools (e.g., screwdrivers, pliers).
Ensure the working area is dry and well-lit.
Never work alone, especially when dealing with live circuits.
Check all connections for tightness and proper insulation before applying power.
Avoid overloading circuits.
Always test circuits for continuity and short circuits before energizing.
Keep flammable materials away from the work area.

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher greets the pupils and reviews the previous lesson briefly. The teacher then introduces the topic by asking pupils if they have ever wondered how a light in their room is turned on and off by a switch, and explains that today’s lesson will involve a practical demonstration and hands-on wiring of a light point controlled by a switch.
Pupils’ Activity: Pupils respond to questions and listen attentively to the introduction.
Learning Point: Pupils are prepared for the lesson and understand its relevance.

Step 2: Circuit Diagram Explanation

Time: 7 minutes
Teaching Skill: Explanation/Illustration
Teacher’s Activity: The teacher sketches the circuit diagram of a light point controlled by a switch on the board or displays a prepared chart. The teacher identifies each component (switch, bulb, power source, cables) and explains their symbols and function in the circuit.
Pupils’ Activity: Pupils observe the diagram, identify the components, and ask questions for clarification.
Learning Point: Pupils understand the theoretical representation of the circuit.

Step 3: Identification of Components and Tools

Time: 5 minutes
Teaching Skill: Identification/Demonstration
Teacher’s Activity: The teacher displays the actual instructional materials (switch, bulb holder, bulb, cables, clips, nails, tools like screwdrivers, pliers, wire stripper) and names each one, briefly explaining its use in the practical wiring.
Pupils’ Activity: Pupils observe the displayed materials and tools, noting their names and uses.
Learning Point: Pupils can identify the physical components and tools needed for the practical.

Step 4: Wiring Procedure Demonstration

Time: 10 minutes
Teaching Skill: Demonstration/Modelling
Teacher’s Activity: The teacher demonstrates the practical surface wiring procedure on a wiring board, carefully showing how to fix components, route cables, strip insulation, make connections, and secure cables with clips and nails. The teacher emphasizes neatness and correct techniques.
Pupils’ Activity: Pupils observe the teacher’s demonstration closely, paying attention to each step and asking questions.
Learning Point: Pupils learn the practical steps and techniques for wiring.

Step 5: Practical Wiring Session

Time: 8 minutes
Teaching Skill: Guided Practice/Supervision
Teacher’s Activity: The teacher divides pupils into small groups (if resources allow) or guides them individually to practice wiring a light point controlled by a switch on their wiring boards. The teacher moves around, providing assistance, correcting mistakes, and ensuring proper technique.
Pupils’ Activity: Pupils actively engage in the practical wiring, following the demonstrated steps and using the provided materials. They seek guidance from the teacher as needed.
Learning Point: Pupils develop hands-on skills in wiring and component installation.

Step 6: Safety Steps Discussion

Time: 3 minutes
Teaching Skill: Discussion/Reinforcement
Teacher’s Activity: The teacher leads a brief discussion on the safety steps to observe during practical electrical wiring, highlighting the dangers of electricity and the importance of using insulated tools and switching off power.
Pupils’ Activity: Pupils contribute to the discussion by mentioning safety precautions they know or have observed.
Learning Point: Pupils understand the critical importance of safety in electrical work.

Step 7: Evaluation/Review

Time: 5 minutes
Teaching Skill: Questioning/Assessment
Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

Sketch the circuit diagram of a light point controlled by a switch.
List three important steps in the practical surface wiring procedure.
Mention two ways to correctly use clips and nails for cable installation.
State two important safety measures to observe when performing electrical wiring.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 2 minutes
Teaching Skill: Summarization/Assignment
Teacher’s Activity: The teacher summarizes the main points of the lesson, reinforcing the practical skills learned and the importance of safety. The teacher then gives pupils homework to draw the circuit diagram and list the components needed for the practical.
Pupils’ Activity: Pupils listen to the summary and copy the homework assignment.
Learning Point: Pupils consolidate their learning and are given follow-up tasks.

Lesson Keywords

Circuit Diagram – A visual representation of an electrical circuit using standard symbols.
Surface Wiring – A method of electrical installation where cables and accessories are installed directly on the surface of walls or boards.
Single Pole Switch – An electrical switch that controls one circuit, having one input and one output.
Clips – Devices used to secure electrical cables to a surface.
PVC (Polyvinyl Chloride) – A type of plastic often used for electrical insulation and conduit.
Safety Steps – Procedures and precautions followed to prevent accidents or harm during electrical work.

Differentiation

For pupils who grasp concepts quickly, the teacher can challenge them to identify faults in a pre-wired circuit or to design a circuit for a two-way switch. For pupils who need more support, the teacher will provide closer supervision during the practical session, offer step-by-step guidance, and provide simplified diagrams or pre-stripped cables to ease the process.

Note for teachers using this lesson plan

Ensure adequate practical materials are available for all pupils or groups. Prioritize safety throughout the practical session; emphasize the importance of disconnecting power before any work and using appropriate tools. Encourage pupils to work neatly and methodically. Provide positive feedback and constructive criticism to foster learning and confidence.