Carry out visits to check on overhead cable, it is one of the basic contents of the overhead cable for operation and maintenance. Through visits to check can detect defects to take preventive measures to ensure the safe operation of the line. Typically, transmission line patrol overhead line work should be done "Nine investigations."

A check tower. Check whether the collapse of the tower, tilt, deformation, rot, damage and whether the crack case basis, whether the bent iron member, loose, crooked, or corrosion. See if the iron tower bolt or screw cap iron wire length is not enough, screw worked loose clasp, tie wire break and relaxation, and so on. Is there a bird's nest and other objects on the view tower?

Two check crossarm and fittings. Check whether the cross arm and fittings shift are firmly fixed, whether the weld cracking, and whether the lack of nuts.

Three investigations along with the case. Check whether the ground is along the path of stacked flammable, explosive, or highly corrosive substance, whether the violation is along the road near the building, and the possibility of harm to the line in thunderstorms or windy weather, buildings, and other facilities. Check towers whether to set up other power lines, communication lines, radio lines, and installation loudspeakers and the like. See wiring for electrical equipment unauthorized access.

Four examination lines. Check wiring and lightning cable for off shares, back flowers, corrosion, scratches, and other external damage. view between lines on the ground and nearby buildings or trees near distance, sag, and other compliance requirements, whether the imbalance of three-phase conductors sag phenomenon. view wire connectors are good, with or without heat, severe oxidation, and corrosion traces.

Five check overhead line insulators. Check insulators for cracks, dirt, traces of burns, and flashover. check the degree of deflection in insulator strings and insulator iron damage.

Six check lightning protection devices. Check the size of the gap protection is qualified, and if the auxiliary gap is intact. Check tube arrester external gap is changed, and the ground wire is intact. Check valve type arrester porcelain for cracks, dirt, and flashover burn marks, seal is good. Check deflectors arrester is intact, whether the grounding by water erosion and exposed ground deflectors and grounding connections are secure.

Seven check cables. Check cable if there is rust, loose, off shares, and unit wire uneven stress problem. Pull pile, pile protection if there is decay damage. The anchor cable is loose, lacks soil, and soil filling subsidence. Distaff, wedge clamp, UT-shaped clamp, hold hoop cable fittings Is their rust, UT-shaped clamp nut for loss, turnbuckle stopping means is good. Pull in wood tied into the woods at Le Have phenomenon.

Eight Charlie pole switchgear. Check switchgear installation is solid, without deformation, damage, and traces of discharge, and the operating mechanism is intact, between ministries and to lead to compliance with the provisions of the pitch.

Check cross-cutting nine points. Check whether the new cross-over point, across the distance, meets the safety requirements, the original cross-over point is to endanger the safe operation of the line. Protective measures are complete.