Many schematics or ladder diagrams start with the __________ or ______________ - ___________ circuit, where NO switches would have to be held-closed by operator-panel doors which are closed and safety guards or covers are bolted in place to render live electrical components, as well as drive chains, belts, or gears, inaccessible before the motors can be started.
A) safety or emergency-stop
B) transformer or diodes
C) none of the answers
D) wire numbering or equations
Share your understanding of this question with the correct explanation.