The main difference between bonding and grounding is that bonding creates a low-impedance path for fault current to flow, while grounding provides a path for that current to safely return to the source.
Here's a more detailed breakdown:
Bonding Explained
Bonding connects different metallic parts of an electrical system, or non-electrical metallic components, together. This creates an electrically conductive path between them.
- Purpose:
- To equalize the electrical potential between bonded parts.
- To provide a low-impedance path for fault current.
- Reduces the risk of electric shock if someone touches two conductive parts simultaneously during a fault.
- How it Works: When a fault occurs, the current can flow freely through the bonded components, tripping a circuit breaker or fuse and quickly de-energizing the circuit.
- Example: Bonding metal water pipes, gas pipes, and metal conduits to the electrical panel.
Grounding Explained
Grounding, also known as earthing, connects the electrical system to the earth, typically via a grounding electrode (like a ground rod).
- Purpose:
- To provide a reference point of zero potential for the electrical system.
- To stabilize voltage to ground during normal operation.
- To provide a path for fault current to return to the source, tripping the circuit breaker.
- Limits voltage rise on electrical equipment.
- How it Works: The grounding system provides a low-resistance path for fault current to flow back to the power source, causing the overcurrent protection device (circuit breaker or fuse) to trip, thereby interrupting the circuit.
- Example: Connecting the neutral wire of a service entrance to a grounding electrode (ground rod or water pipe) driven into the earth.
Key Differences Summarized
| Feature | Bonding | Grounding |
|---|---|---|
| Purpose | Equalizes potential; creates low-impedance path | Provides a zero-potential reference; path to earth |
| Connection | Connects metallic parts together | Connects system to earth |
| Function | Distributes fault current | Neutralizes fault current (returns it to source) |
| Shock Hazard | Reduces shock hazard by equalizing potential | Reduces shock hazard by tripping circuit breakers |
In Simple Terms
Think of bonding like creating a wide, easy highway for electricity to flow through metal objects connected to your electrical system. Grounding is like having an escape route to the earth if that electricity accidentally jumps onto those metal objects. Bonding aims to ensure all metallic objects in close proximity have the same electrical potential, minimizing the risk of electrical shock between them. Grounding aims to provide a safe route for unwanted electricity to return to the source and trip the breaker, shutting off the power and preventing a shock. Both work together to create a safer electrical system.
