Question 178Electricity & Electronics - 1st Asst/Chief

The correct answer is A) 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, it indicates that the circuit between the stop switch and the main contactor "M" coil is open. This means the stop switch, when not pushed in (i.e., in the open position), is preventing the contactor coil from being energized, which would prevent the motor from starting. The other options are incorrect because an open main contactor coil (B) would result in 0 VAC between all terminals, and an overload relay contact (C) or an open start switch (D) would not explain the specific voltage readings observed.