NEC Commercial Electrical Practice Test

What is the minimum size aluminum service entrance conductor permitted for a 100 amp service in a dwelling unit?

1. 3 AWG

2. 2 AWG

3. 1 AWG

4. 4 AWG

The correct answer is: 2 AWG

The minimum size aluminum service entrance conductor permitted for a 100 amp service in a dwelling unit is based on the National Electrical Code (NEC) requirements, specifically found in NEC Table 310.16. According to this table, for aluminum conductors, the ampacity is determined by the conductor size and the temperature rating. For a 100 amp service, the NEC specifies that the minimum size aluminum conductor must be 2 AWG. This is because aluminum has a lower conductivity compared to copper, requiring a larger size to carry the same amount of current safely. If a smaller size conductor were used, it could overheat and lead to potential failure or fire hazards. Understanding these requirements ensures compliance with safety regulations and effective electrical system performance in residential applications. It’s crucial to always refer to the latest NEC guidelines when determining conductor sizes for various amperages since safety is the utmost priority in electrical installations.