What is the minimum size GEC required to connect to building steel?

The minimum size Grounding Electrode Conductor (GEC) required to connect to building steel is indeed 4 AWG. This requirement is established by the National Electrical Code (NEC), which sets standards to ensure safety and reliability in electrical installations.

Using a 4 AWG conductor for the GEC when connecting to building steel is based on factors such as the material of the grounding electrode and the anticipated fault current. Building steel is considered an effective grounding method, and grounding systems are crucial for providing a low-resistance path for fault currents, which helps in stabilizing voltage levels and ensuring equipment protection.

If a larger size, such as 2 AWG or 1 AWG, is applied, it exceeds the minimum requirements without being necessary for most applications. Conversely, using a smaller gauge, such as 6 AWG, would not provide sufficient conductivity to adequately manage fault currents, which could pose a safety risk. Thus, the specifications outlined in the NEC guide professionals in determining the correct minimum size for the GEC to maximize safety and effectiveness in electrical systems.