Due to heavy objects hurt the cable, excavator accidentally accidental injury to the cable, the laying of the cable bending over the Ambassador insulation injury, the cable was severely squeezed during shipment and the insulation and protective layer damage, as the underlying subsidence buried cable by the tension is too large , All lead to the insulation damage, even pull off the cable. Cable mechanical damage can be avoided by overhead cables, if it is laid along the wall of the cable should be covered, should be clearly marked buried, and in a timely manner to stop taking soil near the cable lines.