Place the universal transfer switch in the stop position. The user completes the electrical connection of the bezel door device according to the above drawings. Put the universal transfer switch in the open position and observe whether the damper is running normally. After the damper rotates 90 degrees, observe whether the electric actuator can automatically cut off the power and the motor stops working. After the previous step is completed, the universal transfer switch is placed in the closed position to observe whether the damper is operating normally. After the damper is rotated by 90 degrees, observe whether the actuator can automatically cut off the power and the motor stops working. After the previous step is completed, the transfer switch is placed in the stop position, the power is turned off, and the test machine is completed.