Which device is typically used to switch high-current motor loads?

• A. Relay
• B. Timer
• C. Contactor
• D. Circuit breaker

Answer: (C)

Switching a motor that draws a large current requires a switch built to handle that load reliably and repeatedly. A contactor does exactly that: it’s a heavy-duty switch with multiple power contacts that can be controlled by a low-voltage coil, making it ideal for energizing and de-energizing motors. It’s designed to handle the inrush and inductive nature of motor loads and is often used with an overload relay for protection. A timer only provides sequencing and cannot carry the motor current. A relay can switch signals or lower-current loads, but for motors the contactor is the industrial standard because of its higher current rating and durability. A circuit breaker protects against faults by interrupting current, not for regular on/off switching in motor control. So the typical device for switching high-current motor loads is the contactor.