For a 200-amp feeder in a single-family dwelling, what is the smallest conductor size permitted?

For a 200-amp feeder in a single-family dwelling, what is the smallest conductor size permitted?

• A. 1 AWG
• B. 2/0 AWG
• C. 1/0 AWG
• D. 4/0 AWG

Answer: (B)

The limit is set by the current-carrying capacity (ampacity) of the conductor and the material used. Copper conducts more current per cross-sectional area than aluminum, so for a 200-amp feeder the smallest copper size that meets the rating is larger than the smallest aluminum size. In practice, the minimum sizes are typically 1/0 AWG for copper or 2/0 AWG for aluminum. Among the options given, the copper size listed is too small for 200 A, and the 4/0 option is larger than necessary, so the smallest size that meets the requirement within the choices is 2/0 AWG aluminum.

The limit is set by the current-carrying capacity (ampacity) of the conductor and the material used. Copper conducts more current per cross-sectional area than aluminum, so for a 200-amp feeder the smallest copper size that meets the rating is larger than the smallest aluminum size. In practice, the minimum sizes are typically 1/0 AWG for copper or 2/0 AWG for aluminum. Among the options given, the copper size listed is too small for 200 A, and the 4/0 option is larger than necessary, so the smallest size that meets the requirement within the choices is 2/0 AWG aluminum.