What is the minimum number of wires required between two start/stop push button controls?

What is the minimum number of wires required between two start/stop push button controls?

• A. 0
• B. 1
• C. 2
• D. 3

Answer: (B)

The essential idea is that two start/stop push buttons can operate in a single control path with only a single interconnecting conductor between them. In a basic start/stop circuit, one button is normally closed (stop) and the other is normally open (start). They are wired in series along the control circuit so that the control signal (the control power from the supply) must pass through both switches to energize the load (often via a holding contact that keeps the circuit closed after the start button is released). Because the control circuit shares a common feed and return, you only need one wire to link the two pushbuttons together; the other ends are tied to the same supply rails. If additional features or separate feeds are added, more wires would be needed, but for the simplest two-button arrangement, one interconnecting wire is sufficient.

The essential idea is that two start/stop push buttons can operate in a single control path with only a single interconnecting conductor between them. In a basic start/stop circuit, one button is normally closed (stop) and the other is normally open (start). They are wired in series along the control circuit so that the control signal (the control power from the supply) must pass through both switches to energize the load (often via a holding contact that keeps the circuit closed after the start button is released). Because the control circuit shares a common feed and return, you only need one wire to link the two pushbuttons together; the other ends are tied to the same supply rails. If additional features or separate feeds are added, more wires would be needed, but for the simplest two-button arrangement, one interconnecting wire is sufficient.