power cable Test, acceptance and operation of
（1） Test of power cable In addition to handover test and preventive test, insulation test shall also be carried out during construction to identify and check the cable quality and process quality of each link of construction. Before laying, test on the cable reel to identify the cable cup; Tests shall be conducted after and before laying to identify whether the cable is damaged during laying; Test shall be carried out after the construction of cable head to identify the quality of cable head; The cable shall be tested before and after maintenance to identify the maintenance quality.
The main inspection contents are as follows:
(1) The cables shall be arranged in order, the fixing and bending radius of the cables shall comply with the design drawings and relevant regulations, the electrical system shall be free of mechanical damage, and the signboards shall be installed completely, correctly and clearly. The terminals and intermediate joints of oil impregnated paper insulated cables and oil filled cables shall be free from oil leakage;
(2) There should be no sundries in the cable trench and tunnel, the cover plate of the cable trench should be complete, and the lighting, ventilation, drainage and other facilities in the tunnel should meet the design requirements;
(3) The marker posts of directly buried cables shall be consistent with the actual path, and the spacing shall meet the requirements. The signs shall be clear, firm and durable;
(4) The signs and night lighting devices on both sides of the underwater cable line and in the anchorage free area shall meet the design requirements.
3、 Precautions for cable line operation
(1) Do not overload or overheat for a long time. Therefore, the monitoring of cable load current, external temperature and joint temperature should not be ignored;
(2) The cable line feeder protection shall not be put into reclosing. Most of the cable line faults are permanent faults. If the reclosing action is taken, it will inevitably expand the accident and threaten the stable operation of the power grid;
(3) After the feeder of the cable line trips, do not ignore the cable inspection. Focus on whether the cable path is excavated and whether the wires are damaged. If necessary, further inspection and judgment shall be made through tests;
(4) Special attention shall be paid during the operation inspection of directly buried cables: the ground near the cable path shall not be excavated casually; The ground near the cable path shall not scale heavy objects, corrosive substances and temporary buildings; Cable route marker posts and protection facilities shall not be moved or removed at will;
(5) The cable line must be retested before it can be put into use when it resumes operation after being stopped. The insulation resistance of cables that have been cut off for more than a week but less than a month shall be measured by shake before they are put into operation again, and shall not be reduced by 30% compared with the last test record, or withstand voltage test shall be conducted; If the power failure lasts for more than one month but less than one year, the surface voltage test must be conducted, and the test voltage can be half of the preventive test voltage; If the power failure time exceeds the test period, the preventive test must be carried out.
