What should the electrical load on a single circuit be limited by?

The electrical load on a single circuit should be limited by the maximum current rating of the wiring and switches. This rating determines how much electrical current the conductors can safely carry without overheating, which can lead to potential hazards such as electrical fires. Each wire has a specific gauge that corresponds to its current-carrying capacity, often referred to as ampacity. If the load exceeds this capacity, it can cause the wire to overheat, damage the insulation, and create unsafe conditions.

While the power source capacity is important, it is primarily about the overall available power rather than the specific limitations of the circuit. Similarly, the number of devices does play a role in determining the total current draw, but the actual limitation comes from the wiring and switches' ratings. Voltage is important for function but does not limit the safe current capacity of the circuit components directly. Hence, focusing on the maximum current rating ensures safety and compliance with electrical codes.