What size of wire must be used while grounding?

The size of wire that must be used while grounding is commonly specified based on safety standards and the application of the installation. Using a wire size of #2 and above provides adequate conductivity while ensuring mechanical strength and protection against electrical faults.

In grounding applications, the wire is tasked with handling fault currents, which can be significant. A #2 gauge wire is effective in carrying these fault currents safely to ground, reducing the risk of electrical hazards such as fires or equipment damage. Additionally, its larger diameter compared to smaller gauge wires minimizes resistance, allowing for a more effective path for fault current to safely dissipate into the earth.

Choosing a wire size that meets or exceeds the #2 gauge standard is critical for compliance with the National Electrical Code (NEC) regulations, which dictate minimum requirements for grounding conductors to protect both people and property.

Other choices represent sizes that are either not sufficient in some applications where higher fault current handling is necessary or are better suited for different functions, thus reinforcing why #2 is a prudent choice for grounding purposes.