Skip to main content

Electrician Red Seal · Question

When wiring a motor control circuit, why is it essential for the STOP button to be a normally closed (NC) contact and the START button to be a normally open (NO) contact?

The NC STOP button allows continuous current flow to the starter coil until pressed (opening the circuit to stop), while the NO START button temporarily closes

Start free practice for Electrician Red Seal

150 questions · no signup required · 40 free questions per day

Start Practice →

Question: When wiring a motor control circuit, why is it essential for the STOP button to be a normally closed (NC) contact and the START button to be a normally open (NO) contact?

Answer options: ✅ To allow current to flow through the STOP button ordinarily and break the circuit when pressed, while the START button momentarily completes it.

  • To ensure the motor can only be started by pressing both buttons simultaneously.
  • To simplify the wiring diagram and reduce component cost.
  • To prevent nuisance tripping of the overloads during startup.

Correct answer: To allow current to flow through the STOP button ordinarily and break the circuit when pressed, while the START button momentarily completes it.

Explanation: The NC STOP button allows continuous current flow to the starter coil until pressed (opening the circuit to stop), while the NO START button temporarily closes the circuit to energize the coil.

Start free practice for Electrician Red Seal

150 questions · no signup required · 40 free questions per day

Start Practice →

More about Electrician Red Seal

Related Questions

More for Electrician Red Seal candidates

Ready to practice?

Free, no signup required. Build a wrong-question list as you go.

Start Free Electrician Red Seal Practice →

Related courses

Other Canadian certifications candidates often prepare for alongside this one.