Branch Circuits & FeedersQuestion 25 of 120
Using the dwelling service and feeder conductor table, what is the minimum copper conductor size for a 200-ampere single-phase dwelling service?
a.1/0 AWG
b.3/0 AWG
c.4/0 AWG
d.2/0 AWG
Explanation
For single-phase dwelling services and the main power feeder, conductors are permitted to be sized at 83 percent of the service rating, and the dwelling table lists 2/0 copper for a 200-ampere service. The 3/0 answer is what Table 310.16 alone would require without the dwelling allowance, and 1/0 is below what the dwelling table permits.
Law Reference: 2023 NEC §310.12Practice all 120 questions free — no signup required.
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