Class: Senior Secondary School 1 (SS1 / SSS 1)
Term: 3rd Term
Week: 5
Age: 15 years
Duration: 45 minutes
Subject: Electrical Installation and Maintenance Work
Curriculum Theme: Technology
Previous Lesson: Current Operated Circuit Breaker: Types and Principles.
Topic: PRACTICAL CLASS ON THE INSTALLATION OF FUSE
Subject Matter: sketching fuse installation diagram, IEE regulation on fuses, connecting distribution fuse board to 2 points of light controlled by a switch, connecting 2 13 amps socket outlets, safety checks after installation

Specific Objectives

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

Cognitive Domain:

Sketch a basic fuse installation diagram.
Explain key IEE regulations related to fuse installation.
State important safety checks after electrical installation.

Affective Domain:

Appreciate the importance of safety measures in electrical work.
Develop an interest in practical electrical installations.
Recognise the need to follow electrical standards and regulations.

Psychomotor Domain:

Begin connecting a distribution fuse board to two points of light controlled by a switch.
Begin connecting two 13-ampere socket outlets to a distribution fuse board.

Work cooperatively in groups during practical activities.
Communicate effectively about electrical installation procedures.

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 Technology by J. O. Ojo.
https://www.electricaltechnology.org/2019/02/how-to-wire-distribution-board-db-with-rccb-mcb.html
https://www.electrical4u.com/iee-regulations/

Instructional Materials

The teacher will teach this lesson with the aid of:

Distribution fuse board (single-phase).
Wiring board.
Assorted electrical cables.
Basic electrical tools (screwdrivers, pliers, wire strippers).
Two lamp holders, two light bulbs, and one light switch.
Two 13-ampere socket outlets.
Chalk and chalkboard.

Rationale for the Lesson

This lesson helps pupils understand the practical aspects of installing electrical fuses, which is important for ensuring safety in homes and buildings. It enables them to apply theoretical knowledge to real-world electrical systems, preparing them for future careers in electrical installation and maintenance.

Prerequisite/Previous Knowledge

Pupils are expected to have prior knowledge of basic electrical safety rules, types of fuses, and simple electrical circuits.

Lesson Content/Board Summary

PRACTICAL CLASS ON THE INSTALLATION OF FUSE

Sketching Fuse Installation Diagram

An electrical installation diagram is a visual representation showing how electrical components like fuse boards, lights, switches, and sockets are connected in a building. It guides the installer and helps in troubleshooting.

IEE Regulation on Fuses

The Institution of Electrical Engineers (IEE) Regulations (now BS 7671 Wiring Regulations) provide standards for safe electrical installations. Regarding fuses, these regulations ensure:

Correct sizing of fuses for circuit protection.
Proper installation and enclosure of fuse boards.
Accessibility for inspection and replacement.
Protection against overcurrent and short circuits.
Use of appropriate materials and wiring methods.

Connecting Distribution Fuse Board to 2 Points of Light and 2 Socket Outlets

The distribution fuse board (DB) is the central point where electricity from the supply is distributed to various circuits in a building. Each circuit is protected by a fuse or circuit breaker. Connecting lights involves wiring the live, neutral, and earth conductors from the DB through a switch to the lamp holder. Connecting socket outlets involves wiring the live, neutral, and earth conductors directly from the DB to the socket terminals.

Safety Checks After Installation

After completing an electrical installation, several safety checks are important to ensure it is safe and functional. The following are important safety checks:

Visual Inspection: Check for correct wiring, proper connections, and secure enclosures.
Continuity Test: Ensure all conductors (live, neutral, earth) are continuous and correctly connected.
Insulation Resistance Test: Verify that insulation between conductors and earth is adequate to prevent leakage.
Earth Fault Loop Impedance Test: Confirm that the earth fault protection will operate quickly enough in case of a fault.
Polarity Test: Check that switches and protective devices are connected in the live conductor.
Functional Test: Operate all switches and outlets to ensure they work as intended.

Teaching Methods/Instructional Techniques

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

Instructional Procedures

Step 1: Introduction

Time: 3 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher greets the pupils, reviews the previous lesson on types of fuses, and introduces the topic of practical fuse installation. The teacher asks pupils why it is important to install fuses correctly.
Pupils’ Activity: Pupils respond to questions and listen attentively.
Learning Point: Pupils recall previous knowledge and are introduced to the new topic.

Step 2: Explanation of Fuse Installation Diagram

Time: 7 minutes
Teaching Skill: Explanation/Illustration
Teacher’s Activity: The teacher sketches a basic fuse installation diagram on the chalkboard, showing connections from the fuse board to lights and sockets. The teacher explains the symbols and components.
Pupils’ Activity: Pupils observe the diagram, take notes, and ask questions for clarification.
Learning Point: Pupils understand how to read and interpret an electrical installation diagram.

Step 3: Discussion of IEE Regulations on Fuses

Time: 7 minutes
Teaching Skill: Explanation/Discussion
Teacher’s Activity: The teacher explains what IEE regulations are and highlights key regulations concerning the safe installation and use of fuses, emphasizing the importance of proper sizing and protection.
Pupils’ Activity: Pupils listen, contribute to the discussion, and note down important regulations.
Learning Point: Pupils learn about the standards and safety requirements for fuse installation.

Step 4: Demonstration of Connecting Distribution Fuse Board

Time: 8 minutes
Teaching Skill: Demonstration/Practical
Teacher’s Activity: The teacher demonstrates how to safely connect the main supply to the distribution fuse board and how to prepare cables for connecting to light points and socket outlets using the wiring board.
Pupils’ Activity: Pupils observe the demonstration carefully, noting the correct procedures and safety precautions.
Learning Point: Pupils see the practical steps involved in connecting a distribution board.

Step 5: Practical Activity – Connecting Light Points

Time: 7 minutes
Teaching Skill: Guided Practice
Teacher’s Activity: The teacher guides pupils, in groups, to begin connecting the distribution fuse board to two points of light controlled by a switch on their wiring boards. The teacher supervises and offers assistance.
Pupils’ Activity: Pupils, in groups, actively participate in connecting the light points according to the teacher’s instructions.
Learning Point: Pupils begin to develop practical skills in wiring light circuits.

Step 6: Practical Activity – Connecting Socket Outlets

Time: 7 minutes
Teaching Skill: Guided Practice
Teacher’s Activity: The teacher further guides pupils to begin connecting two 13-ampere socket outlets to the distribution fuse board, ensuring correct wiring of live, neutral, and earth.
Pupils’ Activity: Pupils continue their practical work by connecting the socket outlets, seeking clarification when needed.
Learning Point: Pupils begin to develop practical skills in wiring socket circuits.

Step 7: Evaluation/Review

Time: 4 minutes

Teaching Skill: Questioning/Assessment

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

Sketch a simple diagram showing a fuse board connected to a light point.
Mention two IEE regulations related to fuse installation.
List three important safety checks to perform after an electrical installation.
What is the main purpose of a fuse in an electrical circuit?

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 learning points on fuse installation and safety. The teacher assigns homework: research common fuse ratings used in residential buildings.
Pupils’ Activity: Pupils listen to the summary and note down the homework.
Learning Point: Pupils consolidate their understanding of the lesson.

Lesson Keywords

Fuse – A safety device that melts and breaks an electrical circuit when current exceeds a safe level.
IEE Regulations – Standards set for safe electrical installation and wiring.
Distribution Board (DB) – An enclosure containing circuit breakers or fuses for distributing electrical power.
Socket Outlet – A point in a wiring system where a plug can be inserted to draw electrical power.
Circuit – A complete path through which an electric current can flow.

Differentiation

For pupils who grasp concepts quickly, the teacher can encourage them to assist peers or research more advanced wiring diagrams. For pupils needing more support, the teacher will provide closer supervision during practical activities and offer simplified explanations and step-by-step guidance.

Note for teachers using this lesson plan

Ensure all safety precautions are strictly followed during the practical session. Confirm that all tools and materials are in good working condition. Emphasize the importance of correct wiring and earthing. Practical work should be supervised closely, and power should only be applied after thorough checks.