Detection of variable capacitors for maintenance of induction melting furnaces

(1) Gently rotate the variable capacitor shaft, it should feel very smooth, and should not feel tight or even stuck sometimes. When pushing the shaft forward, backward, up, down, left, right, etc., the shaft should not be loose.

(2) Rotate the shaft with one hand and gently touch the outer edge of the film set with the other hand. There should be no looseness. The variable capacitor with poor contact between the rotating shaft and the moving plate can no longer be used.

(3) Place the multimeter in the Rxl0k block, connect the two test leads to the moving piece and fixed piece of the variable capacitor with one hand, and turn the shaft slowly back and forth with only one hand. The pointers of the multimeter should be in place. The infinity position does not move. In the process of rotating the shaft, if the pointer sometimes points to zero, it means that there is a short-circuit point between the moving piece and the fixed piece; if it is turned to a certain angle, the multimeter reading is not infinity but a certain resistance value, indicating that it is variable There is a leakage phenomenon between the capacitor moving piece and the stator piece.