Per NEC 230.79(C), the service disconnect for a one-family dwelling shall have a minimum rating of 100 amperes, 3-wire. Although the calculated load is only 45 amps, the code mandates a minimum of 100A for any single-family dwelling regardless of the calculated demand.

Per NEC 230.79(D), the service disconnect for all installations other than one-family dwellings, two-circuit, or limited-load installations shall be rated not less than 60 amperes. Since the calculated demand is 65 amps—above the 60A minimum—the service disconnect must carry at least 65 amps; the next standard rating per NEC 240.6(A) is 70 amps.

Per NEC 230.79(D), for all other installations (including multifamily buildings), the service disconnect shall be rated not less than 60 amperes. The calculated demand of 58 amps is below the 60A minimum, so the minimum allowed rating of 60 amps governs.

Per NEC 230.79(D), the service disconnect for all other installations (non-dwelling, non-limited-load) shall be rated not less than 60 amperes. Since the calculated demand is 125 amps—well above 60A—the service disconnect must be rated at least 125 amps. The standard 125A rating per NEC 240.6(A) is therefore the minimum required.

Per NEC 230.79(D), the service disconnect for all other installations (including multifamily buildings) shall be rated not less than 60 amperes. With a calculated demand of 92 amps, the disconnect must handle at least 92 amps; the next standard rating per NEC 240.6(A) is 100 amps.