For installations supplying limited loads of a single branch circuit, the service disconnecting means rating must not be less than what?

In the context of the National Electrical Code (NEC), the rating of the service disconnecting means for installations supplying limited loads of a single branch circuit must meet specific minimum requirements to ensure safe and adequate operation. The code specifies that the disconnecting means should not be rated for less than 15 amperes in these situations.

This requirement is in place to ensure that the service disconnect can handle typical household loads without potential overloads, as many common appliances and devices are designed to operate on circuits with this minimum rating. By establishing a 15-ampere rating, the Code helps to ensure that the electrical system remains safe and functional for residential and light commercial applications.

The other ratings, such as 10, 20, and 25 amperes, are either below the minimum requirement established by the NEC for limited loads or do not reflect the standard for safe operation of typical branch circuits. For instance, a service disconnect rated at 10 amperes would not be sufficient for handling the loads typically encountered in residential applications, while 20 and 25 amperes exceed the minimum requirement but do not apply to the specific condition of supplying limited loads of a single branch circuit.