What is the minimum conductor size required for a 100-amp service?

For a 100-amp service, the minimum conductor size is determined by the National Electrical Code (NEC) requirements. The NEC specifies that for copper conductors, a size of 4-AWG is required for a 100-amp service. This size ensures that the conductor can handle the necessary current without overheating and can safely supply the electrical demand of the service.

When choosing conductors, factors such as the ampacity rating, the ambient temperature, and the installation conditions need to be considered to prevent voltage drop and maintain safety. In residential applications, for a 100-amp service, 4-AWG copper is the standard minimum size. This size provides a balance of safety, efficiency, and cost-effectiveness.

While other sizes listed may be suitable for different applications or conditions, 4-AWG copper is the correct minimum for standard residential 100-amp services, aligning with NEC requirements.