If voltage is applied across two speed terminals on a fan motor, what will likely happen?

When voltage is applied across two speed terminals on a fan motor, the most likely outcome is that the motor will experience a short-out or burn-out condition. In a typical fan motor, speed terminals are designed to manage different operating speeds by changing the voltage applied to the motor. If the terminals are incorrectly challenged with voltage not aligned with the motor’s specifications, it can lead to an overload, overheating, and ultimately damage the motor windings.

This scenario occurs because the fan motor relies on a designed electrical configuration to handle various operational speeds. By applying voltage across the wrong terminals, the motor may draw excessive current, leading to potential insulation failure between the windings, which can create a direct short circuit. This condition results in the motor ceasing to function and may lead to permanent damage or "burn-out."

The other choices suggest that the motor would continue to operate efficiently or modify its speed, but in reality, incorrect voltage applications lead to malfunction rather than effective operation.