For a branch circuit that provides power to lights on a single-sided billboard, what is the minimum ampacity for the ungrounded service conductors when the load is 6 amps?

The minimum ampacity for the ungrounded service conductors in this scenario should account for the load requirements and relevant electrical codes. A branch circuit supplying power to lights on a single-sided billboard with a load of 6 amps will need to size the conductors appropriately to ensure safe and efficient operation.

When determining the minimum ampacity, it's essential to consider the continuous load factor as defined by the National Electrical Code (NEC). For circuits with continuous loads, the conductors must be rated for at least 125% of the load. In this case, the calculated required ampacity would be based on the following:

1. The load is 6 amps.

2. For continuous loads, the conductors should be rated for 125% of this load, which is 6 amps × 1.25 = 7.5 amps.

Considering standard conductor ratings, a 10-amp capacity would not provide much headroom, whereas a 15-amp capacity would comfortably cover the minimum needed to ensure both safety and compliance with the code requirements.

Choosing 15 amps as the minimum ampacity allows for a safe operating margin over the calculated 7.5 amps, ensuring the conductors won’t be running at their maximum capacity. This