Which protection devices are normally located in the safety switch just ahead of the motor starter?

• A. Relays
• B. Thermal overloads
• C. Circuit boards
• D. Fuses or Circuit Breakers

Answer: (D)

The main idea is that the disconnect ahead of a motor starter carries the overcurrent protection for the motor circuit. Fuses or circuit breakers are placed in that safety switch because they provide immediate overcurrent protection—opening the circuit quickly if a short or overload occurs, before power reaches the motor and starter. This setup protects both the conductors and the motor itself. Thermal overloads are typically housed in the motor starter (or in a separate overload relay) to protect the motor windings during operation, not in the safety switch. Relays are used for control, not protection, and circuit boards are control electronics rather than protection devices. So the devices normally found in the safety switch ahead of the motor starter are fuses or circuit breakers.