Motor controlsQuestion 18 of 1506

Contactor coils in ladder diagrams are usually given which letter designation?

  1. T
  2. M
  3. S
  4. R
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Correct answer: M

Motor contactor (starter) coils are designated M.

Source: Lessons in Electric Circuits IV: Digital (Kuphaldt), 6.4: Motor Control Circuits

Practice motor controls

Questions last reviewed: 18 October 2026