Grade 10
Computer-Aided Instruction (CAI)
This Computer-Assisted Instruction (CAI) module is designed for Technology and Livelihood Education - 10, Industrial Arts - Electrical Installation and Maintenance (EIM). It supports guided and independent learning in maintenance and troubleshooting activities.
This Learning Activity Sheet (LAS) was designed to develop the learners' knowledge and skills in identifying common electrical troubles and applying their understanding through simple troubleshooting situations.
The learning activity provides guided tasks that learners can complete at their own pace. The activities move from identifying electrical terms to creating or completing practical scenarios.
At the end of the lesson, the learner should be able to:
Ready to begin?
Take the Pre-Test before studying the lesson.
Read carefully the following statements.
Directions: Choose the letter of the correct answer.
This lesson helps you identify common electrical troubles, create simple electrical-trouble scenarios, and explain why knowledge of electrical troubles is important.
Learning Focus: In this part, you will learn the meaning and identifying characteristics of five common electrical troubles. Each topic has two picture spaces: one for a real-life photograph and one for a schematic drawing.
A short circuit occurs when two or more conductors at different electrical potentials come into unintended contact, creating a low-resistance path for current.
How to identify it: A short circuit may produce excessive current and may cause a fuse to blow or a circuit breaker to trip. Sparks, heat, smoke, or a burning smell may also be observed.
An open circuit is an interruption in the conducting path that prevents current from flowing through the circuit.
How to identify it: The electrical path is broken, so current cannot flow normally. A lamp or other load may fail to operate.
A loose connection occurs when a wire or terminal is not securely connected, which may cause intermittent operation, increased resistance, overheating, or electrical arcing.
How to identify it: A device may work sometimes and stop working at other times. A loose terminal may also become warm or show signs of overheating. Do not touch or test a suspected loose connection while energized.
A grounded circuit occurs when a conductor makes unintended electrical contact with a metal frame or panel enclosure.
How to identify it: Look for unintended contact between a conductor and a metal frame, enclosure, or other grounded part.
A ground fault occurs when an energized conductor comes into unintended contact with the earth or a grounded part, such as the metal frame or enclosure of electrical equipment.
How to identify it: An energized conductor may contact a grounded part. Circuit protection, such as a circuit breaker or ground-fault protective device, may interrupt the supply when a fault condition occurs.
Safety reminder: Never touch, open, or test suspected faulty electrical equipment while it is energized. Isolate the supply and refer the equipment to a qualified person.
Understanding possible causes can help a learner recognize conditions that may lead to electrical troubles.
Live and neutral conductors may come into contact because of improper connections or unsecured terminations.
Stripped or damaged insulation can expose conductors and increase the possibility of unintended contact.
An improperly tightened wire termination may become loose and create an unsafe condition.
Animals such as mice and rats may chew electrical wires and damage their insulation.
Damaged or defective appliances may develop electrical faults in plugs, power cords, or internal components.
Too many devices connected to the same circuit can cause the circuit to carry more current than intended.
A short circuit or overload may cause the circuit breaker to trip.
Look for damaged wires or melted insulation.
Switch off the affected circuit and unplug appliances before inspection.
Only reset the breaker when it is safe to do so. If it immediately trips again, do not repeatedly reset it.
Identify which appliance, switch, receptacle, or circuit component may be associated with the fault.
An appliance that repeatedly trips the breaker may have an electrical fault.
If the problem cannot be safely identified, seek assistance from a qualified electrician.
Learning Focus: A scenario is a short description of a situation that shows what happens in a real or possible electrical condition. You can create an electrical-trouble scenario by describing the situation, the observed condition, and the electrical trouble involved.
Describe where or when the problem happens.
Describe what happens or what is observed.
Identify the electrical trouble shown.
Situation: A learner switches on a lighting circuit.
Observation: The circuit breaker suddenly trips after two damaged conductors come into contact.
Electrical Trouble: Short circuit.
Explanation: The unintended contact between conductors creates a low-resistance path that can cause excessive current.
Situation: A learner switches on a lamp.
Observation: The lamp does not light because one wire is cut and the electrical path is interrupted.
Electrical Trouble: Open circuit.
Explanation: The circuit is incomplete, so normal current cannot flow through the complete path.
Situation: A lamp is connected to a wall switch.
Observation: The lamp sometimes works and sometimes turns off. Inspection shows that a terminal is not securely tightened.
Electrical Trouble: Loose connection.
Situation: An appliance has a damaged conductor inside its enclosure.
Observation: The conductor touches the metal frame.
Electrical Trouble: Grounded circuit.
Situation: Water enters an electrical device while an energized conductor is exposed.
Observation: The circuit protection device interrupts the electrical supply.
Electrical Trouble: Ground fault.
Understanding common electrical troubles is important because electrical problems can affect the proper operation and safety of electrical systems.
“Knowing common electrical troubles is important because it helps me recognize unsafe conditions, understand why a circuit may not operate normally, and follow proper safety procedures when troubleshooting.”
You may express your own idea using your own words.
In this lesson, you learned about five common electrical troubles: short circuit, open circuit, loose connection, grounded circuit, and ground fault.
You also learned how to identify these troubles by looking at their definitions, characteristics, conditions, and examples.
You learned that a simple electrical-trouble scenario can be created by describing a situation, an observation, and the electrical trouble involved.
Finally, you learned why understanding electrical troubles is important for safety, identification, troubleshooting, prevention, and responsible electrical practice.
Before proceeding to the activities, make sure you can:
Directions: Arrange the jumbled letters to form the correct electrical term. Type your answer in the blank provided.
Learning Target: Create or complete simple scenarios showing common electrical troubles.
Directions: Read each situation carefully. Complete the scenario by explaining what electrical trouble is shown and what should be observed or investigated. Use your own words.
Your answers should show your understanding of the five electrical troubles discussed in the lesson: short circuit, open circuit, grounded circuit, loose connection, and ground fault.
What electrical trouble is shown? Explain what may happen because of this condition.
Guide: Think about unintended contact between conductors and excessive current.
What electrical trouble is shown? Explain why the lamp cannot operate normally.
Guide: Think about a broken or interrupted electrical path.
What electrical trouble is shown? Explain why contact with the metal frame is a concern.
Guide: Think about an unintended connection between a conductor and a metal frame or enclosure.
What electrical trouble is shown? Explain why the condition may cause intermittent operation.
Guide: Think about an insecure wire or terminal connection.
What electrical trouble may be present? Explain how water or contact with grounded parts can contribute to the hazard.
Guide: Think about an energized conductor coming into contact with ground or grounded parts.
Directions: Explain and give a brief statement of the following. Write your answers in the space provided.
This rubric is used to evaluate Activity 2 and the learner's Reflection.
| Criterion | 5 Points | 3 Points | 1 Point |
|---|---|---|---|
| 1. Clarity | Clear | Partially clear | Not clear |
| 2. Accuracy | All accurate | 1-Inaccurate | More than one inaccurate |
| 3. Relevance | All relevant | 1-Irrelevant | More than one irrelevant |
| Criterion | 5 Points | 3 Points | 1 Point |
|---|---|---|---|
| 1. Clarity | Clear | Partially clear | Not clear |
| 2. Thoughtfulness | All thoughtful | 1 answer lacks thoughtful consideration | More than one answer lacks thoughtful consideration |
| 3. Relevance | All relevant | 1 irrelevant | More than one irrelevant |
Maximum rating: 5 points per criterion. Each rubric has three criteria.
Read carefully the following statements.
Directions: Choose the letter of the correct answer.
This section contains the references used in preparing this Computer-Assisted Instruction (CAI) material. List only sources that were actually consulted and cited in the lessons, activities, and assessment materials.