What formula is commonly used to calculate total ampacity for a feeder?

The chosen answer is accurate because it correctly follows the rearranged formula used to calculate amperage, which is integral to determining total ampacity for a feeder. The relation is based on the power formula, which states that power (in kVA) is equal to the product of amperage and voltage. By rearranging this relationship, one can derive the formula for amperage as the total load (in kVA) divided by the voltage (in volts). This formula effectively gives the current in amperes that a feeder would need to support the specified load at a given voltage.

Understanding this relationship is crucial for load calculations, as ampacity must be properly determined to ensure that electrical systems are safe, efficient, and compliant with applicable codes and standards. The ability to manipulate these formulas allows electricians and engineers to design systems that can handle the electrical demands of buildings and facilities appropriately.

When it comes to the other options, they either misrepresent the relationship between these variables or do not correctly address how to derive amperage from total load and voltage. This highlights the importance of grasping the fundamental principles of electrical calculations, ensuring that one can accurately size feeders for various applications.