Gas Heat ESCO Practice Exam

What will happen if voltage is applied across two speed terminals on a fan motor?

1. The motor will short out

2. The motor will run at maximum speed

3. The motor will be damaged

4. The motor will stop

The correct answer is: The motor will short out

When voltage is applied across two speed terminals on a fan motor, it can lead to a scenario where the motor experiences an electrical fault. This is primarily because these terminals are designed to operate under specific conditions, and incorrectly applying voltage can create a direct path that bypasses normal operating parameters. Consequently, this short-circuiting can overload the motor's winding, leading to overheating and potential physical damage to the motor itself. The concept of applying voltage across multiple terminals typically involves interactions that are not meant to occur simultaneously, and thus can create a hazardous situation. The intended operation usually requires the selection of one speed at a time, ensuring that the motor functions safely at the desired speed without excess current draw that could lead to a short circuit. In cases where the motor is already functioning under a predefined speed setting, applying voltage incorrectly can indeed cause immediate failure or malfunction, reinforcing the importance of adhering to proper wiring and voltage application protocols.