(1) The joint shaft is smooth and flexible, and the casting should not have cracks, blisters or rust.
(2) The inside of the fuse tube should be cleaned, and the fuse installation should be properly tightened and tightened. The copper braided wires at both ends of the fuse should not be twisted or broken.
(3) The fuses are installed firmly and neatly arranged. The angle between the axis of the fuse and the vertical line should be 150-300. After the fuse is blown, the drop action should be flexible and reliable, the contact should be tight, the upper and lower leads should be compacted, and the line conductors The connection should be tight and reliable.
(4) The porcelain body is good, and the melt pipe should not have the phenomenon of moisture absorption expansion or bending.