Which table is used to determine the minimum size copper service conductors for a 200 A service?

Which table is used to determine the minimum size copper service conductors for a 200 A service?

• A. NEC Table 310.12
• B. NEC Table 250.94
• C. NEC Table 230.70
• D. NEC Table 300.5

Answer: (A)

Sizing copper service conductors hinges on matching the conductor’s ampacity to the service rating using the appropriate ampacity table. For a 200 A service, you look up copper conductor ampacities in NEC Table 310.12, which lists conductor sizes and their allowable current-carrying capacities based on insulation temperature ratings (60°C/75°C/90°C). By selecting the insulation rating that applies to the conductors and terminations, you identify the smallest conductor size whose ampacity meets or exceeds 200 A. The other tables referenced in the choices pertain to different topics (such as grounding electrode conductors, service equipment requirements, or raceway fill) and aren’t used to determine the minimum size of service conductors.

Sizing copper service conductors hinges on matching the conductor’s ampacity to the service rating using the appropriate ampacity table. For a 200 A service, you look up copper conductor ampacities in NEC Table 310.12, which lists conductor sizes and their allowable current-carrying capacities based on insulation temperature ratings (60°C/75°C/90°C). By selecting the insulation rating that applies to the conductors and terminations, you identify the smallest conductor size whose ampacity meets or exceeds 200 A. The other tables referenced in the choices pertain to different topics (such as grounding electrode conductors, service equipment requirements, or raceway fill) and aren’t used to determine the minimum size of service conductors.