Grounding electrical wire involves connecting the ground wire (typically bare copper or green insulated) from your cable to specific points on electrical boxes, devices, and fixtures to create a safe path for fault current.
Proper grounding is crucial for electrical safety, helping to prevent electric shock and protect equipment. The method for grounding varies slightly depending on the component you are wiring.
Here’s how grounding is typically done for common electrical components, based on established practices:
Grounding Electrical Boxes and Receptacles
Metal electrical boxes and receptacles require a secure connection to the grounding system. This ensures that if a live wire accidentally touches the metal box or the device housing, the fault current is safely routed away, tripping the circuit breaker.
- Methods:
- Pigtail Method: This involves connecting the ground wire from the cable to a short piece of wire (a "pigtail") using a wire connector. The other end of the pigtail is then connected to the ground screw on the metal box and/or the ground terminal on the receptacle.
- Grounding Clip: For metal boxes, a grounding clip can be used to attach the cable's ground wire directly to the box edge. Receptacles still require a connection from the box's ground point or a separate ground wire from the cable directly to the receptacle's ground terminal.
- Reference 1 states: Metal boxes and receptacles are grounded by the pigtail method or with a grounding clip.
Grounding Light Fixtures
Light fixtures with metal housings or components also need to be grounded.
- Method:
- Connect the fixture's ground wire (often green) to the grounding system. This is typically done by connecting it to the ground wire coming from the electrical cable in the box, or if using a metal box, connecting it to the strap or housing of the metal box itself, which is already grounded.
- Reference 2 states: Fixtures are grounded by connecting a ground lead to a ground wire or the strap on a metal box.
Grounding Switches
Electrical switches, especially those with metal parts, need to be grounded to ensure safety if an internal fault occurs.
- Method:
- Switches have a dedicated ground screw (usually green). The ground wire from the incoming electrical cable is connected directly to this screw. If the switch is in a metal box that is properly grounded, this connection also grounds the box.
- Reference 3 states: Switches use ground screws to connect to grounding wires.
By following these methods, you establish a continuous and safe path for electricity back to the main electrical panel and the earth ground, significantly reducing the risk of electrical hazards. Always ensure the power is off before performing any electrical work.
