Class: Senior Secondary School 2 (SS2 / SSS 2)
Term: 3rd Term
Week: 5
Age: 16 years
Duration: 45 minutes
Subject: Basic Electricity
Curriculum Theme: Electrical Installations
Previous Lesson: Lighting Points and Switches: Identification of Lighting Points and Control Switches.
Topic: WIRING REGULATION 2
Subject Matter: Meaning of cable termination (definition), preparation of cable ends (stripping insulation), method of termination of cables (connector block).

Specific Objectives

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

Cognitive Domain:

Define cable termination.
Explain the steps involved in preparing cable ends for termination.
Describe the method of terminating cables using a connector block.

Affective Domain:

Appreciate the importance of proper and safe cable termination.
Show interest in learning practical electrical wiring skills.

Psychomotor Domain:

Demonstrate the correct technique for stripping cable insulation.
Successfully terminate a cable using a connector block.

Work cooperatively with peers during practical demonstrations.
Understand the societal benefits of correctly wired electrical systems.

Reference Materials

The following resources were used in planning this lesson:

Senior Secondary Schools Education Curriculum
State Unified Scheme of Work
Basic Electricity for Senior Secondary Schools by P.N. Okeke
https://www.electricaltechnology.org/2019/07/cable-termination-types-methods.html
https://www.youtube.com/watch?v=1F6rA9s3Tf4

Instructional Materials

The teacher will teach this lesson with the aid of:

Various types of electrical cables (e.g., single-core, multi-core)
Different sizes of connector blocks (terminal blocks)
Wire strippers
Screwdrivers (flathead and Phillips)
Measuring tape/ruler

Rationale for the Lesson

This lesson is important because it teaches pupils the fundamental skills required for making safe and reliable electrical connections. Proper cable termination prevents electrical hazards and ensures the efficient operation of electrical systems in homes and industries.

Prerequisite/Previous Knowledge

Pupils are expected to have prior knowledge of different types of electrical cables, their components, and basic electrical safety rules.

Lesson Content/Board Summary

WIRING REGULATION 2: CABLE TERMINATION

1. Meaning of Cable Termination

Cable termination is the process of connecting the end of an electrical cable to a device, another cable, or a terminal point. This process ensures a good electrical connection, mechanical support, and protection against environmental factors.

2. Preparation of Cable Ends

Proper preparation of cable ends is essential for a safe and effective termination. The steps include:

Measuring: Determine the correct length of insulation to be removed, usually matching the depth of the terminal block.
Stripping Insulation: Carefully remove the outer insulation using a wire stripper without nicking or damaging the conductor strands. Ensure only the required length of insulation is removed.
Twisting Strands (for stranded cables): Gently twist the exposed conductor strands together in a clockwise direction to prevent fraying and ensure all strands enter the terminal.

3. Method of Termination: Using a Connector Block (Terminal Block)

Connector blocks are commonly used to join two or more cables or to connect cables to electrical components. The steps for terminating a cable using a connector block are:

Step 1: Select the Correct Connector Block: Choose a connector block suitable for the cable size and current rating.
Step 2: Prepare the Cable Ends: Measure and strip the cable insulation to the appropriate length (usually 5-10mm, depending on the block) and twist the strands if necessary.
Step 3: Loosen Terminal Screw: Use a screwdriver to loosen the screw in the desired terminal hole of the connector block.
Step 4: Insert the Cable: Insert the prepared bare conductor end fully into the terminal hole, ensuring no insulation is under the screw and no bare conductor is exposed outside the terminal once tightened.
Step 5: Tighten the Screw: Firmly tighten the terminal screw with the correct screwdriver. Tug gently on the cable to ensure it is securely held and cannot be easily pulled out.
Step 6: Repeat for Other Cables: If connecting multiple cables, repeat the process for all cables in their respective terminal points.

Safety Note: Always ensure power is off before working on electrical connections. Use insulated tools.

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 introduces the topic by asking pupils about the importance of making good electrical connections in their homes.
Pupils’ Activity: Pupils respond by mentioning safety, preventing sparks, and ensuring appliances work.
Learning Point: Pupils are introduced to the concept of safe electrical connections.

Step 2: Meaning of Cable Termination

Time: 7 minutes
Teaching Skill: Explanation/Definition
Teacher’s Activity: The teacher defines cable termination, explaining its purpose in providing good electrical contact and mechanical support.
Pupils’ Activity: Pupils listen attentively and copy the definition into their notebooks.
Learning Point: Pupils understand what cable termination means.

Step 3: Importance of Proper Cable Termination

Time: 6 minutes
Teaching Skill: Discussion/Elaboration
Teacher’s Activity: The teacher discusses why proper cable termination is important, emphasizing safety, prevention of short circuits, and reliable operation of electrical systems.
Pupils’ Activity: Pupils contribute to the discussion and note the key points.
Learning Point: Pupils appreciate the significance of correct termination practices.

Step 4: Preparation of Cable Ends

Time: 8 minutes
Teaching Skill: Demonstration/Practical
Teacher’s Activity: The teacher demonstrates how to correctly prepare cable ends by measuring, stripping insulation without damage, and twisting strands using appropriate tools.
Pupils’ Activity: Pupils observe the demonstration carefully and ask questions for clarification.
Learning Point: Pupils learn the practical steps for preparing cable ends.

Step 5: Method of Termination (Connector Block)

Time: 10 minutes
Teaching Skill: Demonstration/Practical
Teacher’s Activity: The teacher demonstrates the step-by-step process of terminating a cable using a connector block, ensuring all safety precautions are highlighted.
Pupils’ Activity: Pupils observe the demonstration, noting the careful insertion and tightening of the cables, and may get a chance to practice under supervision.
Learning Point: Pupils understand and can apply the method of using a connector block for termination.

Step 6: Safety Precautions

Time: 4 minutes
Teaching Skill: Emphasizing/Reinforcement
Teacher’s Activity: The teacher reiterates crucial safety precautions to observe during any electrical wiring task, such as switching off power and using insulated tools.
Pupils’ Activity: Pupils listen and confirm their understanding of the safety rules.
Learning Point: Pupils are reminded of essential safety practices.

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

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

What is cable termination?
List three steps involved in preparing cable ends for termination.
Describe how you would terminate a cable using a connector block.
State two important safety precautions to observe during cable termination.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 3 minutes
Teaching Skill: Summarizing/Assignment
Teacher’s Activity: The teacher summarizes the key points of the lesson and assigns homework, asking pupils to draw and label a simple diagram showing a cable terminated in a connector block.
Pupils’ Activity: Pupils listen to the summary and copy the homework assignment.
Learning Point: Pupils consolidate their learning and are given a task to reinforce understanding.

Lesson Keywords

Cable Termination – The process of connecting a cable end to a device or terminal.
Connector Block – A device used to join electrical cables securely.
Stripping Insulation – Removing the outer protective layer of a cable to expose the conductor.
Conductor Strands – The individual wires within a cable that carry electrical current.
Electrical Safety – Practices and procedures to prevent injury or damage from electricity.

Differentiation

For pupils who grasp the concepts quickly, the teacher can challenge them to explain different types of cable terminations or the purpose of ferrule crimping. For pupils needing more support, the teacher can provide one-on-one guidance during practical demonstrations and use simplified diagrams.

Note for teachers using this lesson plan

Ensure all practical demonstrations are conducted safely, with power switched off. Provide enough materials for pupils to practice if time permits. Emphasize the importance of neatness and precision in all wiring work. Encourage questions and hands-on participation.