Garis Panduan Pendawaian Elektrik - 7. Pembumian

Introduction

This tutorial provides essential guidelines for electrical earthing, as discussed in the Crux Of EE YouTube video series on electrical wiring standards. Understanding earthing is crucial for ensuring safety in residential electrical installations, preventing electric shocks, and protecting equipment from damage.

Step 1: Understand the Importance of Earthing

• Earthing is a safety measure that connects the electrical system to the ground.
• It prevents electric shock by providing a low-resistance path for fault currents.
• Proper earthing protects electrical equipment from surges and lightning strikes.

Step 2: Identify Types of Earthing Systems

• System Earthing: This refers to how the electrical system is grounded. Common types include:
  • TT System: Earth connections made locally at the consumer's premises.
  • TN System: Earth connections made at the supply network, ensuring a direct path to the ground.
  • IT System: No direct connection to earth, relying on insulation.

Step 3: Design the Earthing System

• Determine the required earthing resistance, typically less than 1 ohm for effective grounding.
• Consider the soil resistivity, which affects the earthing system's performance.
• Use appropriate earthing conductors, such as copper or aluminum, to connect the system to the ground.

Step 4: Installation of Earthing Electrodes

• Choose the type of earthing electrode based on local soil conditions:
  • Rod Electrode: Driven into the ground and made of copper or galvanized steel.
  • Plate Electrode: Buried metal plate that disperses current into the ground.
  • Strip Electrode: A conductive strip installed at a depth to enhance grounding.
• Ensure that the electrode is driven deep enough to reach moisture and reduce resistance.

Step 5: Connect All Equipment to the Earthing System

• Connect all electrical installations, including:
  • Distribution boards
  • Metallic structures
  • Appliances with metal casings
• Use suitable connectors and ensure that connections are tight and corrosion-resistant.

Step 6: Test the Earthing System

• Conduct tests to verify the effectiveness of the earthing system:
  • Earth Resistance Test: Measure the resistance between the earth electrode and the general mass of earth.
  • Continuity Test: Check the continuity of the earthing connections to ensure they are intact.

Step 7: Maintain the Earthing System

• Regularly inspect and test the earthing system to ensure it remains effective.
• Look for signs of corrosion or physical damage to earthing conductors and electrodes.
• Replace any faulty components immediately to maintain safety standards.

Conclusion

Proper earthing is fundamental to electrical safety in residential wiring. By understanding the principles of earthing, designing an effective system, and performing regular maintenance, you can significantly reduce the risk of electric shock and equipment damage. For further information, consider exploring the other videos in this series or reach out to professionals for assistance.