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

When voltage is applied across two speed terminals on a fan motor, it can create a scenario that leads to the motor burning out. In many motors, especially those designed for specific speeds, applying voltage incorrectly across terminals can cause the motor to attempt to operate in a manner it wasn't intended for. Motor windings are designed to handle certain voltages and conditions; when those parameters are exceeded, it can lead to overheating.

This overheating can result from excessive current flow that occurs when incorrect voltage is applied. The increased electrical load generates more heat than the motor can dissipate, leading to thermal breakdown. The insulation on the motor windings can fail, the windings can short-circuit, or the motor can seize up entirely, resulting in burnout.

Understanding how fan motors operate and their speed terminals is crucial for maintaining equipment and ensuring proper function. Proper voltage application is key for the longevity of the motor and avoiding damage.