Question 132Electricity & Electronics - QMED

70% to pass

In the illustrated motor controller, the motor fails to start. A voltmeter reading between 1 and 5 reads line voltage, while the voltmeter reading between 2 and 5 reads 0 VAC. What is most likely the problem? Illustration EL-0007

Diagram for USCG Electrical QMED: In the illustrated motor controller, the motor fails to start. A voltmeter...

Aan open start switch contact (when pushed in)

Ban open stop switch contact (when not pushed in)

Can open main contactor "M" coil

Dan overload "OL" relay contact

AI Explanation

The correct answer is B) an open stop switch contact (when not pushed in). The reasoning is that with line voltage present between terminals 1 and 5, but 0 VAC between terminals 2 and 5, the issue is likely an open circuit in the stop switch contact. When the stop switch is not pushed in (open contact), it breaks the circuit and prevents the motor from starting, even though line voltage is present. The other options are incorrect because an open start switch (A) would prevent voltage from reaching the motor, an open main contactor coil (C) would also prevent the motor from starting, and an overload relay contact (D) would only open after the motor has already started.