Why 1.25 in calculating minimum circuit ampacity?

Answer 1

In calculating minimum circuit ampacity, the factor of 1.25 is commonly applied to account for continuous loads. This multiplier ensures that the circuit can handle the load without overheating, providing a safety margin by increasing the ampacity rating. By using 1.25, the calculation considers potential variations in load and allows for the safe operation of electrical equipment over extended periods. This practice aligns with the National Electrical Code (NEC) guidelines to promote safety and reliability in electrical installations.