AR is auto restart and current shutdown function. It is the most effective protection to prevent from fan malfunction due to rotation problem.
When the rotor is stopped by external force, and then make the fan stopped rotating, the stator appears high current status. It is the maximum output current. A fan with AR function, its IC is to stop the power in two seconds. Then, the fan will not be damaged due to high temperature accumulated from long time use. After the fan IC cuts the power three seconds, it restarts until the external force being removed and then continues rotating.
This function protects the fan and electric equipment effectively. Detailed expression and relevant diagram are to provide from the samples approval sheets.