Use more outdoor cable installation is mainly copper and aluminum transition terminal failure is mainly copper and aluminum transition terminal, therefore, The McNair electrical terminals expert as follows Analysis of the main reasons blown cable terminals.

(1)terminal quality does not meet the requirements of national standards

Eight kinds of commonly used copper and aluminum transition terminal as an example for the comparison of the relevant size indicators with national standards, the quality of terminals currently in use are the following problems: screw hole is too large, so that the terminals of the contact area of ??narrow, easy mounting bolts loose; the thinning of the outer diameter of the terminal, wall change workbook; shallow tube depth shorter wire insertion portion; to shorten the length of the part of the copper in the copper and aluminum transition; contact with the surface part of the width is reduced, so that the reduced contact area; contact surface the thickness of the part is reduced.

(2) The installation process does not fine

During the installation process, terminals and equipment clamp whether a good connection, but also to ensure the safety of power supply conditions, one of the outdoor cables that occurred the first terminal fuse, carefully checked and found that the contact part of the lead clamps and terminals melting point-like, this is also the corrosion of copper and aluminum are two different metal contact with the battery contact area of poor contact caused by overheating burning, which is the second reason.

(3) the uneven load distribution

In the power transmission process, each phase of the load is uneven, it will cause a phase or two-phase load is low, the other phase or two-phase high load situation, the load current long-term is too large, the terminals it increase the probability of failure of the cable line, accelerated insulation aging and shorten the service life of the cable, resulting in damage to the overheating of the external contact of the terminal head, the dangers of the cable circuit overload is already apparent.

(4) lightning and other

In addition to the above three reasons, the summer lightning, line faults, but also lead to another reason for cable outdoor cable head blown terminal.