Fuse with maintenance：

1）Short circuit fault or overload operation and normal fusing;

2）Melt use time is too long, or in the operation of high temperature melt due to oxidation, make the melt characteristics change and WuDuan；

3）Melt when installing mechanical damage, make its cross-sectional area smaller and WuDuan is caused in the running。

2、When changing the melt, the requirement to do：

1）Before installing new melt, to identify the reasons for the melt fuse, did not identify the cause of the fuse, not changing the melt try to send；

2）Replace a new melt, should check the rating of the melt is match the protected equipment；

3）To replace a new melt, check the fuse internal burns, if you have severe burns, should be replaced at the same time fusion tube. Porcelain fused tube damage, are not allowed to use other material tube instead. Packing fuse replacement melt, attention should be paid to fill the packing.

3、Fuse and distribution equipment maintenance work at the same time：

1）Cleaning the dust, check the contact point contact condition；

2）Check the fuse appearance (remove the fuse tube) with and without damage, deformation, twinkle porcelain for discharge；

3）Check the fuse, the melt and the protection circuit or equipment match, if there is any problem should be timely investigation；

4）Pay attention to check in TN grounding system of N line, line equipment grounding protection, are not allowed to use the fuse；

5）Maintenance check fuse, according to the requirements of the safety rules, cut off power supply, don't allow charged gather the fuse tube。