What is the minimum size for an underground service-lateral conductor?

The minimum size for an underground service-lateral conductor is properly specified as 6 AWG aluminum or 8 AWG copper. This sizing is essential for ensuring that the conductor can handle the expected load while also maintaining safe operating temperatures and minimizing losses due to resistance.

Aluminum conductors have a larger diameter than copper conductors to provide a comparable ampacity, which is why 6 AWG aluminum can effectively replace the need for a slightly larger 8 AWG copper conductor. This sizing is based on the National Electrical Code (NEC) requirements, which establish standards for safety and performance in electrical installations. Having the correct size conductor is critical in preventing overheating and ensuring reliable service, especially in underground installations where ambient conditions may vary and accessibility for maintenance can be challenging.

Understanding these specifications helps electricians ensure compliance with NEC standards and promotes safety in electrical installations.