"Cross Flow Fan" when the test is not less than two persons, one power control, a person was observed cooling fan is running, abnormal phenomenon immediately stop inspection; First check the direction of rotation is correct; after centrifugal fan starts running, you should immediately check the phase operating current is balanced, if the current exceeds the rated current; if not normal, you should stop to check. After running five minutes, stop to check whether the cooling fan anomalies, confirming that no anomalies and then start running. When two-speed centrifugal cooling fan test, you should start low, check the direction of rotation is correct; must be stationary when starting the fan speed and then start to prevent high-speed reverse rotation, causing damage to the motor and switch tripping.