Red Seal Electrician Practice
Motor controlsQuestion 109 of 1506

What are permissive contacts in a furnace burner control?

  1. Contacts wired in parallel, so that any one of them can start the burner
  2. Auxiliary contacts that stop forward and reverse starting together
  3. Contacts that seal in the start button after it is released
  4. Process switch contacts in series, which all must be closed before a start
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Correct answer: Process switch contacts in series, which all must be closed before a start

If any permissive detects an unsafe condition, the circuit opens.

Source: Lessons in Electric Circuits IV: Digital (Kuphaldt), 6.3: Permissive and Interlock Circuits

Practice motor controls

Questions last reviewed: 18 October 2026