What is the minimum size branch circuit rating when supplying more than one cord and plug connected load?

The minimum size branch circuit rating when supplying more than one cord and plug connected load is 15 amperes. This rating is based on the National Electrical Code (NEC), which specifies that branch circuits that supply outlets for cord and plug connected loads must have a rating sufficient to handle the cumulative load they might experience.

When multiple appliances or devices are connected using cords and plugs, it's important to ensure that the branch circuit can handle the combined load safely. A 15-ampere circuit is typically adequate for residential applications where multiple smaller appliances, such as lamps or small kitchen devices, might be used simultaneously. Additionally, the use of a 15-ampere branch circuit helps to mitigate the risk of overheating and potential fire hazards that could arise from overloading circuits.

In general, for circuits supplying more substantial or specialized loads, higher ratings such as 20 or 30 amperes may be necessary. However, for the situation described, which involves more than one standard cord and plug connected load, a 15-ampere rating strikes a balance between safety and usability in a residential setting.