In motor control, a normally closed contact is typically opened to ______ the motor during an overload.

In motor control, a normally closed contact is typically opened to ______ the motor during an overload.

• A. Disconnect
• B. Energize
• C. Maintain operation
• D. Ground the motor

Answer: (A)

Opening a normally closed contact stops current to the motor. Normally closed means the contact conducts in normal operation, so the motor runs. When an overload is detected, the control system opens that contact, breaking the circuit and de-energizing the motor. This interruption protects the motor from overheating and damage by removing power. Energizing would power the motor, which is the opposite action during an overload. Maintaining operation would keep the motor running despite the overload, which is unsafe. Grounding the motor isn’t the intended overload protection method, since grounding directs fault current rather than reliably stopping the motor. So opening the contact to disconnect the motor is the correct action.

Opening a normally closed contact stops current to the motor. Normally closed means the contact conducts in normal operation, so the motor runs. When an overload is detected, the control system opens that contact, breaking the circuit and de-energizing the motor. This interruption protects the motor from overheating and damage by removing power. Energizing would power the motor, which is the opposite action during an overload. Maintaining operation would keep the motor running despite the overload, which is unsafe. Grounding the motor isn’t the intended overload protection method, since grounding directs fault current rather than reliably stopping the motor. So opening the contact to disconnect the motor is the correct action.