What rating is required for the service disconnect in a one-family dwelling according to the standards?

The correct rating for the service disconnect in a one-family dwelling is 100 Amperes. This rating is based on the National Electrical Code (NEC) requirements, which are designed to ensure adequate power supply for typical residential use while maintaining safety standards. A 100 Amp service disconnect provides sufficient capacity to power the basic electrical needs of a household, including lighting, appliances, and HVAC systems, while allowing for future expansion if necessary.

Using a rating lower than 100 Amperes may not accommodate the electrical load of modern appliances and systems, potentially leading to overloading and hazardous situations. A higher rating, such as 150 Amperes, while sometimes used in larger homes or those with significant electrical demands, is not the minimum required standard for a typical one-family residence. Therefore, the 100 Amp service disconnect rating strikes a balance between safety, usability, and compliance with established electrical codes.