Basic Electricity - Senior Secondary 3 - Insulation

Insulation

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TERM: 1ST TERM

WEEK FIVE

Class: Senior Secondary School 3

Age: 17 years

Duration: 40 minutes of 5 periods each

Date:

Subject: BASIC ELECTRICITY

Topic: INSULATION TEST

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

I.) Define installation test

II.) Identify the types of installation test

III.) Give a summary of the test result interpretations for installation test

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures,

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

PRESENTATION

TEACHER’S ACTIVITY

STUDENT’S

ACTIVITY

STEP 1

INTRODUCTION

The teacher explains the meaning of installation test and discuss the types of installation test

Students listens attentively to the teacher                                                                          

STEP 2

EXPLANATION

Teacher outline and explain the test result interpretations for various installation test

Students exhibit attentiveness and active engagement

STEP 3

NOTE TAKING

The teacher writes a summarized

note on the board

The students

copy the note in

their books

 

NOTE

INSULATION TEST

An installation test, also known as electrical installation testing, is a procedure conducted to verify the safety, functionality, and compliance of electrical installations with relevant standards and regulations. These tests are typically performed during the installation, commissioning, or periodic maintenance of electrical systems to ensure their safe and reliable operation.

Types of installation tests

  1. Continuity Test: This test verifies the continuity of electrical conductors (such as wires, cables, and bonding connections) to ensure that there are no breaks or discontinuities in the circuit. It is typically performed using a low-resistance ohmmeter or a multimeter to measure the resistance between various points in the circuit.
  2. Polarity Test: Polarity testing ensures that the connections of electrical devices, such as sockets, switches, and appliances, are correctly aligned with the supply voltage polarity. Polarity testers or phase rotation meters are commonly used to perform this test.
  3. Earth Leakage Test: This test checks for the leakage of current to the earth from electrical circuits or equipment. It helps identify insulation faults, which could pose a risk of electric shock or fire.

 Earth leakage tests are conducted using specialized instruments called earth leakage testers or insulation resistance testers.

  1. Insulation Resistance Test: Insulation resistance testing evaluates the insulation integrity of electrical conductors, cables, and equipment. It measures the resistance between conductors and between conductors and earth to ensure that insulation is sufficient to prevent leakage currents.

Insulation resistance testers apply a high-voltage DC test voltage to the insulation and measure the resulting current flow.

Summary of the test result interpretations for each type of test:

Test Type

Test Result

Interpretation

Continuity Test

Low Resistance    

 

 

 

High Resistance or Open Circuit

Continuity is present, indicating that there are no breaks or discontinuities in the circuit.

Indicates a break or discontinuity in the circuit, requiring further investigation and repair.

Polarity Test    

Correct Polarity   

 

 

 Incorrect Polarity           

Connections are aligned correctly with the supply voltage polarity.     

Connections are not aligned correctly with the supply voltage polarity, requiring correction                  

Earth Leakage Test 

Low Leakage Current

 

 

 

High Leakage Current        

Insulation integrity is adequate, and leakage current to earth is within acceptable limits. 

Indicates insulation faults or leakage paths, posing a risk of electric shock or fire.         

Insulation Resistance Test

High Insulation Resistance 

 

 

Low Insulation Resistance   

Indicates good insulation integrity, with minimal leakage current and adequate safety margin

Indicates insulation breakdown or faults, requiring corrective action to prevent safety hazards.

 

 EVALUATION: 1. What is installation test?

  1. State the 4 types of installation test
  2. Interpret the test result for continuity test.

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively