Earthing Systems: RCDs and Grounding

Earthing Systems

Residual Current Devices (RCDs)

• Also known as Ground Fault Circuit Interrupters (GFCIs)
• Designed to protect people from electrical shock by detecting and interrupting ground faults
• Operate by comparing the current flowing through the live and neutral conductors
• If a difference is detected, the device trips, disconnecting power to the circuit
• Typically used in applications where there is a high risk of electrical shock, such as:
  • Outdoor areas
  • Construction sites
  • Bathrooms and kitchens
  • Swimming pools and hot tubs

Grounding Systems

• Types of grounding systems:
  • TN-S (Separate Neutral and Earth): Most common type, uses a separate neutral and earth conductor
  • TN-C (Combined Neutral and Earth): Less common, uses a single conductor for both neutral and earth
  • TT (Terre-Terre): Used in areas where a reliable earth connection is not available
  • IT (Isolated Terra): Used in applications where a high degree of electrical isolation is required
• Purpose of grounding systems:
  • To provide a safe path to earth for fault currents
  • To protect people and equipment from electrical shock
  • To facilitate the detection of ground faults
• Key components of a grounding system:
  • Earthing electrode (e.g. rod, plate, or grid)
  • Earthing conductor (connects the electrode to the electrical system)
  • Grounding busbar (connects multiple grounding conductors)

Note: These notes provide a brief overview of the key concepts related to earthing systems, specifically Residual Current Devices and Grounding Systems.

Learn about Residual Current Devices (RCDs) and Grounding Systems, including their types, purposes, and key components. Understand how they protect people and equipment from electrical shock.