Class: Senior Secondary School 1 (SS1 / SSS1)
Term: Second Term
Week: 8
Age: 15 years
Duration: 45 minutes
Subject: Electrical Installation and Maintenance Work
Curriculum Theme: Technology
Previous Lesson: Current Rating of a Cable: Factors and Conductors.
Topic: INTRODUCTION TO CONDUIT SYSTEM OF WIRING.
Subject Matter: meaning of conduit system of wiring, advantages of conduit wiring, disadvantages of conduit wiring, types of conduit system of wiring, conduit components and sizes

Specific Objectives

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

Cognitive Domain:

Define conduit system of wiring.
State at least three advantages of conduit wiring.
Mention at least two disadvantages of conduit wiring.
List the different types of conduit systems.
Identify various conduit components and state common sizes.

Affective Domain:

Appreciate the importance of proper wiring systems in electrical installations.
Show interest in learning about different electrical wiring methods.
Value safety practices associated with electrical conduit installations.

Psychomotor Domain:

Identify actual samples of conduit pipes and fittings.
Distinguish between different types of conduit components.

Participate actively in class discussions about conduit wiring.
Collaborate with peers to identify conduit components from displayed samples.

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, Book 1.

Instructional Materials

The teacher will teach this lesson with the aid of:

Samples of PVC conduit pipes (e.g., 20mm, 25mm).
Various conduit fittings samples (e.g., bends, elbows, saddles, junction boxes).
Charts showing diagrams of different conduit systems and components.

Rationale for the Lesson

This lesson helps pupils understand a fundamental method of electrical wiring that is widely used for safety and durability. Understanding conduit systems enables pupils to appreciate how electrical cables are protected and safely routed in buildings, which is important for their future work in electrical installations.

Prerequisite/Previous Knowledge

Pupils are expected to have basic knowledge of electrical circuits, conductors, insulators, and general safety precautions in electrical work.

Lesson Content/Board Summary

INTRODUCTION TO CONDUIT SYSTEM OF WIRING

Meaning of Conduit System of Wiring

A conduit system of wiring is an electrical wiring method where electrical conductors (wires) are enclosed in tubes or pipes called conduits. These conduits provide protection to the wires from mechanical damage, moisture, and fire hazards. The conduits can be made of metal or plastic materials.

Advantages of Conduit Wiring

The following are advantages of conduit wiring:

It provides excellent protection against mechanical damage to the wires.
It offers good protection against moisture and dust.
It provides protection against fire hazards by containing sparks or short circuits.
It gives a neat and aesthetic appearance to the installation when concealed.
It allows for easy replacement or addition of wires in the future.
It is durable and has a long lifespan.

Disadvantages of Conduit Wiring

The following are disadvantages of conduit wiring:

The initial cost of installation is higher compared to other wiring systems.
Installation can be complex and requires skilled labour.
It is time-consuming to install.
Maintenance and fault finding can be difficult, especially in concealed conduits.

Types of Conduit System of Wiring

The following are common types of conduit systems:

Rigid Metal Conduit (RMC): Made of galvanized steel or aluminum, offering strong protection.
Intermediate Metal Conduit (IMC): Thinner-walled than RMC but still provides good protection.
Electrical Metallic Tubing (EMT): A lighter-gauge steel conduit, often called thin-wall conduit, joined by clamps or compression fittings.
Flexible Metal Conduit (FMC): Made of spiral-wound metal, allowing for flexibility in installation.
Rigid Polyvinyl Chloride (PVC) Conduit: Made of plastic, resistant to corrosion and chemicals, commonly used for concealed wiring.
Flexible Non-metallic Conduit: Made of plastic, used where flexibility is needed and metal protection is not required.

Conduit Components and Sizes

Conduit systems use various components to form a complete wiring pathway. Common conduit components include:

Conduit Pipes: The main tubes that house the wires.
Conduit Bends/Elbows: Used to change the direction of the conduit run.
Junction Boxes: Used for making connections, splices, or tapping off wires.
Couplings: Used to join two lengths of conduit.
Saddles/Clips: Used to secure conduits to walls or surfaces.
Inspection Bends/Boxes: Allow access to wires at bends for pulling or inspection.
Adaptors: Used to connect conduits to other electrical fittings.

Conduit pipes come in various standard sizes, typically measured by their outer diameter in millimeters (mm) or inches. Common sizes include 20mm, 25mm, 32mm, 40mm, and larger, depending on the number and size of wires to be protected.

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, reviews the previous lesson briefly, and then introduces the new topic by asking pupils about ways electrical wires are protected in buildings.
Pupils’ Activity: Pupils respond to the teacher’s questions and listen attentively.
Learning Point: Pupils are prepared for the new lesson and connect it to their prior knowledge.

Step 2: Meaning of Conduit System of Wiring

Time: 7 minutes
Teaching Skill: Explanation/Definition
Teacher’s Activity: The teacher explains the meaning of a conduit system of wiring, emphasizing its purpose of protecting electrical conductors. The teacher uses charts and real-life examples to illustrate.
Pupils’ Activity: Pupils listen, observe the charts, and ask questions for clarification.
Learning Point: Pupils understand the definition and basic purpose of conduit wiring.

Step 3: Advantages and Disadvantages of Conduit Wiring

Time: 8 minutes
Teaching Skill: Explanation/Discussion
Teacher’s Activity: The teacher discusses the advantages of conduit wiring, such as protection against damage, moisture, and fire. The teacher also explains the disadvantages, including higher cost and complex installation.
Pupils’ Activity: Pupils listen, take notes, and contribute to the discussion by mentioning points they know.
Learning Point: Pupils identify the benefits and drawbacks of using conduit wiring systems.

Step 4: Types of Conduit System of Wiring

Time: 8 minutes
Teaching Skill: Classification/Explanation
Teacher’s Activity: The teacher explains and lists the different types of conduit systems (e.g., Rigid Metal, PVC, Flexible Metal), describing their characteristics and common uses. The teacher refers to charts.
Pupils’ Activity: Pupils observe the charts, listen carefully, and note down the different types.
Learning Point: Pupils can differentiate between various types of conduit systems.

Step 5: Conduit Components and Sizes

Time: 7 minutes
Teaching Skill: Demonstration/Identification
Teacher’s Activity: The teacher displays samples of various conduit components (pipes, bends, junction boxes, saddles) and explains their function and common sizes. The teacher encourages pupils to handle and observe the components.
Pupils’ Activity: Pupils observe, touch, and identify the displayed conduit components and their sizes.
Learning Point: Pupils recognize and understand the use of different conduit components and their typical sizes.

Step 6: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

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

What is a conduit system of wiring?
State three advantages of using conduit wiring.
Mention two disadvantages of conduit wiring.
List any three types of conduit systems.
Name two common conduit components and their functions.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 7: Conclusion

Time: 5 minutes
Teaching Skill: Summarization/Assignment
Teacher’s Activity: The teacher summarizes the key points of the lesson, reiterating the importance of conduit systems in electrical installations. The teacher assigns homework: “Draw and label any four conduit components.”
Pupils’ Activity: Pupils listen to the summary and copy the homework assignment.
Learning Point: Pupils consolidate their understanding and are given an activity to reinforce learning.

Lesson Keywords

Conduit – A tube or pipe used to protect and route electrical wiring.
Rigid Metal Conduit (RMC) – A heavy-duty metal pipe used for electrical wiring protection.
PVC Conduit – Plastic pipes made of polyvinyl chloride used for electrical wiring, common in concealed installations.
Junction Box – An enclosure for connecting or joining electrical wires.
Saddle – A fitting used to secure conduit pipes to surfaces.

Differentiation

The teacher will provide additional support to struggling pupils by offering simplified explanations and more direct guidance during the identification of components. Advanced pupils will be encouraged to research specific applications of different conduit types and present their findings.

Note for teachers using this lesson plan

Teachers should ensure all instructional materials, especially the conduit samples, are available and safe for pupils to handle. Emphasize safety precautions during any discussions related to electrical installations. Encourage active participation and practical observation to enhance learning.