1、風扇標籤錯誤（無TUV及UL認證）---人為疏忽； 2、風扇啟動時

1. Incorrect fan label (without TUV and UL certification) --- human negligence; 2. Noise when the fan is started --- our company reassembled 5 fans. During the test, it was found that 3 of them were normal, and 2 of them were slightly noisy when started . After disassembling the 5 fans, the analysis found that the vertical column centrality of the fan frame with slight noise is relatively large (one 22 and one 30), and the verticality of the good product central column is small (the good product is 12-15). Confirm the judgment, select the good product frame, and measure at each station (details are as follows)

1, fan label error (no TUV and UL certification) --- human negligence; 2, fan start-up noise--- I Reassembled 5 fans, test found 3 normal, 2 start-up with slight noise. For 5 fan disassembly, analysis found that the slight noise fan fan box center column vertical ity is too large (1 set 22, 1 set 30), good product center column vertical ity is small (good products in 12-15), in order to confirm the determination, select good product box, each station for measurement (specifically below table)

1. Fan label error (no TUV and UL certification) - human negligence; 2. Noise during fan startup - our company reassembled 5 fans, and found that 3 fans were normal during test, and 2 fans had slight noise during startup. After disassembling 5 fans, it is found that the perpendicularity of fan frame central column is too large (1 set of 22, 1 set of 30), and the perpendicularity of good product central column is too small (good product is 12-15). In order to confirm and judge, good product frame is selected and measured at each station (see the table below for details)<br>