What is the minimum size of XHHW aluminum conductors for a 100 amp service entrance supplying a dwelling unit?

The minimum size for XHHW aluminum conductors for a 100 amp service entrance supplying a dwelling unit is 2 AWG. This size is established based on the National Electrical Code (NEC) guidelines, which set specific conductor size requirements for different ampacity ratings depending on the material and insulation type.

Aluminum conductors have a different ampacity compared to copper conductors. For a 100 amp service, the NEC tables specify that 2 AWG aluminum conductors are sufficient to safely carry the load while meeting the necessary temperature rating and other safety requirements. This sizing helps in preventing overheating and ensuring that the electrical system operates efficiently and safely without the risk of voltage drop or other associated problems.

Other conductor sizes, such as 4 AWG, would not meet the amperage needs for a 100 amp service per the NEC requirements and could lead to unsafe operating conditions or code violations. Understanding these sizing requirements is critical for ensuring compliance with electrical codes and for the overall safety of the electrical infrastructure in residential settings.