When connected across-the-line in a control circuit, what is the maximum number of pilot device contact sets that can be series-connected?

• A. Two
• B. Five
• C. As many as required
• D. Only three

Answer: (C)

In a control circuit, pilot devices are used to indicate the status or condition of a system. When connected across-the-line, pilot device contact sets can be series-connected without a fixed limit, provided that the overall design takes into account operational parameters such as voltage, current, and the total resistance of the combined devices.

The key reason for allowing as many pilot device contact sets as needed is that each contact adds to the functionality of the circuit without inherent restrictions, meaning that you can series-connect multiple contacts to achieve the desired logic or signal indication. However, practical considerations such as the voltage drop across each contact and the possible impact on load current must be managed. As long as these factors are adequately addressed, the number of pilot contacts can be increased to meet the requirements of the circuit.

Therefore, the correct answer acknowledges the flexibility in design that allows for connecting multiple sets of contacts according to the needs of the application.