(1) electrical connection line or clip is not enough to burn the stock or broken.
(2) electric connection line scattered stock is serious, be burned off the stock or burn line.
(3) serious corrosion of the electrical connection, resulting in cross-section flow is not enough to be burned strand or burning line.
(4) electrical connection with the clamp or bad contact with the contact line contact with the bad line, resulting in burning.
(5) clip and clue contact carrier surface is not enough, resulting in burning.
(6) loosening of a clamp nut is not found and dealt with in time, resulting in loss of electronic connectors.
(7) No temperature change after electronic connector mounting Offset or too little offset.
(8) After the installation of electronic connectors offset the value of the larger deviation, the bearing cable and the contact line between the vertical electrical connection line relaxation, to relaxation to the lower part of the contact line, was in operation in the pantograph to fight Bad or cut off. Vertical part of the bottom circle and the contact line spacing is too small, pantograph bad or cut bad.
(9) contact line power supply clip clip installed skewed by the pantograph, which led to cut bow accident.
(10) Occur in other locations of the catenary bow, pantograph to continue to run to the electronic connector installation, the electronic connector cut bad.