When a calculation results in a fraction of an ampere of what value or more, can the NEC® permit rounding up to the next ampere?

The National Electrical Code (NEC) allows for rounding up when the calculation results in a value of 0.5 amperes or more. This means that if the calculated value is 0.5 or higher, it can be rounded up to the next whole number in amperes. This approach ensures that the installation meets the requirements for capacity and safety, as underestimating the current could lead to overheating and other safety hazards.

Rounding up to the next ampere for values below 0.5 would lead to potential undersizing of conductors or protective devices, which is generally not permitted. Therefore, understanding the rounding rules according to NEC is essential for ensuring electrical systems are designed with proper safety margins.