Secondary circuits of transformers and electronic power supplies for electric signs shall not be connected in what configuration?

The correct answer emphasizes that secondary circuits of transformers and electronic power supplies for electric signs should not be connected in a parallel configuration. This is because when multiple secondary circuits are connected in parallel, there can be issues with uneven load distribution. This can lead to overcurrent situations where one circuit carries more current than the others, potentially causing damage to components or creating safety hazards.

In addition, connecting circuits in parallel can complicate troubleshooting and maintenance procedures, as it makes it difficult to isolate individual circuits when necessary. Proper circuit design prioritizes both safety and reliability, which parallel connections can undermine in this scenario.

While series connections have their own specific considerations, they maintain a more predictable current flow through each element in the circuit, especially when used within the intended constraints of their design. Therefore, the best practice is to avoid parallel connections for secondary circuits in this context, ensuring a safer and more effective operation of electric signs powered by transformers and electronic power supplies.