If a continuous load on a lighting branch circuit is 16A, what should the overcurrent device be sized at?

When determining the appropriate size of an overcurrent protection device for a continuous load, it is necessary to follow the guidelines set by the National Electrical Code (NEC). The NEC stipulates that for continuous loads, the overcurrent protective device must be rated at least 125% of the continuous load.

In this case, the continuous load on the lighting branch circuit is 16A. To find the required size of the overcurrent device, you would calculate 125% of 16A:

1. Calculate 125% of 16A:

16A x 1.25 = 20A.

This calculation indicates that the overcurrent protection device should be rated at least 20A to adequately protect the circuit under continuous load conditions.

Choosing a 20A overcurrent protection device allows for the safe operation of the circuit and complies with NEC requirements, ensuring that the device will not trip under normal operation when the load is continuous at 16A. Therefore, the correct answer is to size the overcurrent device at 20A.