What is the minimum service disconnect rating for installations that supply only limited loads of a single branch circuit?

The minimum service disconnect rating for installations that supply only limited loads of a single branch circuit is 15A. This is established to ensure that the circuit can handle typical residential loads safely, accommodating the standard devices and appliances that may be connected. The 15A rating is significant because it represents the capacity to support standard lighting and receptacle circuits, which are common in most residential settings.

When considering the ratings for service disconnects, it's important to ensure that they align with the National Electrical Code (NEC) requirements, which aim to promote safety and reliability in electrical installations. A rating of 15A is adequate for protecting these lighter load circuits while providing sufficient overhead to avoid nuisance tripping during normal operation. Higher ratings, such as 20A or more, would typically apply to circuits serving larger loads, such as dedicated appliances, which is why they are not appropriate for installations meant for limited loads of a single branch circuit.

Thus, the 15A rating stands out as the minimum required for such scenarios, ensuring compliance with applicable electrical standards while maintaining safety in domestic electrical systems.