"Waterproof Cooling Fan" power, using test pencil checking metal parts, there should be no leakage phenomenon. He shook his head and shook his head when devices require coherent smooth, low noise, no gap pause, there should be no stagnation or sudden bounces or "giggle" sound phenomenon, shaking his head angle should be greater than 80 to 90 degrees. Requirements can be started at a low gear when no "buzzing" sound, no vibration when the sound "imperfections" sound, fast file running, howling, knock. "Waterproof Cooling Fan" in a swing position to start with the most low-end, the fan quickly up to speed, particularly when under 0.85 times the rated voltage can be normal start; when changing gear, there are significant changes in the amount of wind; let the fan in high gear under operation, the device operates and shaking his head, "Waterproof Cooling Fan" should be no significant unusual noise. Work within 30 minutes, the motor no obvious hot feeling.