What are the causes of power cable failure?

Update:20 Sep 2017
Summary:

    1. Directly damaged by external forces: such as urb […]

    1. Directly damaged by external forces: such as urban construction, transportation, underground pipeline construction, piling, lifting, transport and other accidental injury cable.
    2. Construction damage: such as traction is too large, excessive bending, ultra-low temperature brutal construction, cable stripping damage.
    3. Natural damage: such as due to the free travel of the cable pipe, the cable at the bracket skin scratches; due to land settlement, landslides and other damage caused; due to bad weather caused by cable damage; due to frequent vibration cable lines caused by damage.

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