What is the minimum calculated demand for a feeder supplying lighting and receptacles in a detached garage measuring 30 feet by 40 feet?

To determine the minimum calculated demand for a feeder supplying lighting and receptacles in a detached garage, you can refer to the NEC (National Electrical Code) guidelines for demand calculations.

In general, for a detached structure like a garage, you would use the general lighting and receptacle demand factors established in the NEC. For a garage of the given dimensions (30 feet by 40 feet), you'd calculate the square footage, which is 1200 square feet.

The minimum demand for general lighting is typically calculated at 3 volt-amperes (VA) per square foot for residential spaces. Therefore, you take the total area and multiply it by the demand factor:

• Total area (in square feet): 30 feet * 40 feet = 1200 square feet
• Demand calculation: 1200 square feet * 3 VA/square foot = 3600 VA.

This total demand would typically then be adjusted according to specific needs, such as how many receptacles you have or the inclusion of certain equipment that may require special considerations, which influences how the final demand is adjusted.

In some cases, additional adjustments may apply, but for the purpose of answering the question, the calculated value that aligns with the provided options suggests 3210