Class: Senior Secondary School 1 (SS1 / SSS 1)
Term: 1st Term
Week: 8
Age: 15 years
Duration: 45 minutes
Subject: Electrical Installation and Maintenance Work
Curriculum Theme: Technology
Previous Lesson: Striking Tools: Types and Uses.
Topic: CABLE: Definition, Types, and Preparation
Subject Matter: definition of cable, types of cables used in electrical installation, PVC cable as an example, preparation of cables for use, basic cable stripping and handling

Specific Objectives

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

Cognitive Domain:

Define what a cable is.
List and identify different types of cables used in electrical installations.
Describe the steps involved in preparing a cable for use.

Affective Domain:

Appreciate the importance of selecting the correct cable type for different applications.
Show willingness to follow safety procedures during cable preparation.

Psychomotor Domain:

Identify various cable types from samples.
Demonstrate basic cable stripping and handling techniques.

Participate actively in discussions about cable types and their applications.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum for Electrical Installation and Maintenance Work (Senior Secondary Education)
State Unified Scheme of Work for Electrical Installation and Maintenance Work (SS1)
Electrical Installation Technology by J.O. Omoniyi

Instructional Materials

The teacher will teach this lesson with the aid of:

Various PVC cable samples
Other cable samples (e.g., flexible cable, armoured cable)
Wire stripper
Insulation tape
Cutting pliers

Rationale for the Lesson

This lesson helps pupils understand the basic component for transmitting electricity – the cable. Knowing about different cable types and how to prepare them safely is important for practical electrical work and everyday safety around electrical appliances.

Prerequisite/Previous Knowledge

Pupils have basic knowledge of electricity and some common electrical tools.

Lesson Content/Board Summary

Cables: Definition, Types, and Preparation

Definition of Cable

A cable is an electrical conductor or a group of conductors insulated from one another and from surrounding objects. It is used to transmit electrical energy or signals from one point to another.

Types of Cables Used in Electrical Installation

The following are common types of cables used in electrical installations:

PVC Insulated Cables: Polyvinyl Chloride (PVC) is a common insulating material. These cables are widely used for general wiring in homes and buildings.
Armoured Cables: These have an additional layer of metallic armouring for mechanical protection, making them suitable for underground installations or areas where physical damage is a risk.
Flexible Cables: Designed to withstand repeated bending, these are used for connecting portable appliances like irons, fans, and vacuum cleaners.
Rubber Insulated Cables: Often used in industrial settings or for heavy-duty applications due to their flexibility and durability.
Mineral Insulated Cables (MICC): These cables are highly fire-resistant and are used in emergency lighting and fire alarm systems.

PVC Cable

PVC cables are the most common type for domestic and light commercial wiring. They consist of a conductor (copper or aluminium) insulated with a layer of PVC. They can be single-core or multi-core.

Preparation of Cables for Use

Preparing a cable for use involves several steps to ensure a good electrical connection and safety. These steps include:

Measurement: Measuring the required length of cable using a tape measure.
Cutting: Cutting the cable to the desired length using appropriate cutters or pliers.
Stripping: Carefully removing the outer insulation and conductor insulation to expose the metallic conductor, using a wire stripper.
Cleaning: Cleaning the exposed conductor if necessary to remove any oxidation or dirt.
Termination: Connecting the prepared cable to terminals, connectors, or other electrical components.

Basic Cable Stripping and Handling

Cable stripping is the process of removing the insulating material from the end of a cable to expose the conductor. Proper stripping involves:

Using the correct size of wire stripper to avoid damaging the conductor.
Stripping only the necessary length of insulation.
Avoiding nicks or cuts on the conductor strands, which can weaken the cable.

Proper handling involves keeping cables free from kinks, sharp bends, and physical damage that can compromise their integrity and safety.

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 asks them to mention some electrical appliances they use daily. The teacher then guides them to identify what connects these appliances to power sources.
Pupils’ Activity: Pupils mention appliances and identify cables as the connecting medium.
Learning Point: Pupils recall previous knowledge and are introduced to the lesson topic.

Step 2: Definition of Cable

Time: 7 minutes
Teaching Skill: Explanation/Definition
Teacher’s Activity: The teacher explains the definition of a cable using simple terms and writes it on the board.
Pupils’ Activity: Pupils listen attentively, take notes, and ask questions for clarification.
Learning Point: Pupils understand the basic definition of an electrical cable.

Step 3: Types of Cables Used in Electrical Installation

Time: 10 minutes
Teaching Skill: Demonstration/Explanation
Teacher’s Activity: The teacher displays various cable samples (PVC, flexible, armoured) and explains the characteristics and uses of each type, highlighting their differences.
Pupils’ Activity: Pupils observe the displayed cables, identify them, and note their features and applications.
Learning Point: Pupils can identify and differentiate between various types of cables.

Step 4: Focus on PVC Cable

Time: 5 minutes
Teaching Skill: Detailed Explanation
Teacher’s Activity: The teacher gives a more detailed explanation of PVC cables as a common example, discussing their structure (conductor and insulation).
Pupils’ Activity: Pupils listen and contribute by mentioning places where they have seen PVC cables used.
Learning Point: Pupils gain specific knowledge about PVC cables.

Step 5: Preparation of Cables for Use

Time: 8 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher explains the general steps for preparing cables for use (measurement, cutting, stripping, cleaning, termination) and briefly demonstrates the cutting and measuring aspects.
Pupils’ Activity: Pupils pay attention to the steps and observe the demonstration.
Learning Point: Pupils understand the sequential process of cable preparation.

Step 6: Basic Cable Stripping and Handling

Time: 5 minutes
Teaching Skill: Practical Demonstration/Guidance
Teacher’s Activity: The teacher demonstrates how to safely strip a PVC cable using a wire stripper, emphasizing correct technique and safety precautions. The teacher then allows a few pupils to attempt under supervision.
Pupils’ Activity: Pupils observe the stripping demonstration and some practice the skill.
Learning Point: Pupils learn the practical skill of cable stripping and safe handling.

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

Define what an electrical cable is.
Mention three types of cables used in electrical installations.
State any two steps involved in preparing a cable for use.
What is the main purpose of an armoured cable?

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
Teacher’s Activity: The teacher summarizes the key points of the lesson and assigns homework, asking pupils to draw and label three types of cables.
Pupils’ Activity: Pupils listen to the summary and copy the homework assignment.
Learning Point: Pupils consolidate their learning and prepare for further study.

Lesson Keywords

Cable – An insulated electrical conductor or group of conductors used for transmitting electricity.
Conductor – The material within a cable (usually copper or aluminium) that allows electricity to flow through it.
Insulation – The non-conductive material (e.g., PVC, rubber) that surrounds the conductor to prevent electrical leakage and ensure safety.
Stripping – The process of removing the outer insulation from a cable to expose the conductor.
PVC Cable – A common type of cable insulated with Polyvinyl Chloride, widely used in domestic wiring.

Differentiation

For pupils who grasp concepts quickly, the teacher can challenge them to research specialized cable types (e.g., data cables, fibre optic cables). For those needing more support, the teacher can provide additional one-on-one guidance during the practical stripping session and use simplified diagrams.

Note for teachers using this lesson plan

Ensure that all cable samples are safe to handle and that the wire stripper is in good working condition. Emphasize safety precautions when demonstrating cable stripping to prevent accidents. Encourage pupils to ask questions and share their observations.