What would be the minimum size branch circuit if the calculated ampacity is 20.45 A?

To determine the minimum size branch circuit when the calculated ampacity is 20.45 A, it is important to understand that electrical circuits are generally sized based on standard ampere ratings to ensure safety and code compliance.

Given that the calculated ampacity is 20.45 A, the branch circuit must be able to handle this current without exceeding its rated capacity. The National Electrical Code (NEC) specifies that you cannot round down when dealing with continuous loads; instead, you should round up to the nearest standard ampacity rating.

In this context, a branch circuit must be selected from standard sizes. Since 20.45 A rounds up to the next standard size, a 25 A circuit would be appropriate to accommodate the load safely. However, the minimum size according to standard practice would be a 20 A circuit. A 20 A circuit could, in some contexts, be considered adequate, especially for non-continuous loads, but generally, you would choose a size above the calculated load, leading to choosing 25 A.

The correct selection indicates a cautious approach to circuit design, ensuring that the branch circuit can handle the load with an adequate safety margin to account for any potential fluctuations in current demand. While 20 A meets