If a continuous load on a branch circuit is measured at 12A, what should the overcurrent protection be sized at?

When determining the correct sizing of overcurrent protection for a continuous load, it is essential to follow the guidelines set by the National Electrical Code (NEC). A continuous load is defined as one where the load is expected to operate for three hours or more. According to NEC guidelines, overcurrent protection for continuous loads must be sized at 125% of the continuous load current.

In this case, the continuous load is measured at 12A. To find the appropriate overcurrent protection size:

1. Calculate 125% of the load: 12A × 1.25 = 15A.

Thus, the overcurrent protection should be rated at no less than 15A to safely allow for the continuous operation of the load while preventing any potential overheating that could occur if the circuit is subjected to excessive current.

Choosing a size of 15A ensures compliance with the NEC and provides a safety buffer. Opting for a size larger than this, such as 20A, could lead to inadequate protection of the circuit and potentially allow overload conditions to persist, which may pose a risk of fire or damage to the circuit components.