The minimum rating of a disconnecting means for an outdoor feeder supplying a building with only 2 branch circuits is what amperage?

The minimum rating of a disconnecting means for an outdoor feeder supplying a building with only two branch circuits is 30 amperes. This requirement is grounded in the National Electrical Code (NEC), which specifies that a minimum disconnecting means be rated to accommodate the maximum anticipated load of the circuits served. In the case of a feeder with two branch circuits, a 30-ampere disconnect is deemed suitable to ensure safety and functionality, providing adequate capacity to handle the load. This aligns with the NEC's intent to provide sufficient power supply while also ensuring that the disconnect can handle potential overloads without failing or presenting safety hazards.

Other options would exceed the necessary minimum for this situation. A rating less than 30 amperes, such as 20 amperes, would be insufficient for a dual-circuit feeder and could lead to operational issues. Ratings higher than 30 amperes, such as 40 or 50, while they may provide more capacity, are not specifically required as the minimum. Thus, 30 amperes stands as the appropriate and code-compliant answer for this scenario.