Before running the cable network, the security work must be done well.
1. Load monitoring. commonly power cable The maximum current value of the line is specified according to the cross-sectional area of the cable conductor, insulation type, etc. Various instruments are used to measure the load current of the wire line or the cable skin temperature, etc., as the main load monitoring measures, to prevent the cable insulation from exceeding the allowable maximum temperature and shortening the cable life.
2. Temperature monitoring. The temperature of cable shall be measured in summer or when the wire is under maximum load. When measuring the temperature of directly buried wires, the soil temperature in the same section without other heat sources shall be measured. When the cable is laid across or close to the underground heat pipe, the soil temperature around the cable shall not exceed 10 ℃ above the soil temperature of the same depth in other parts of the local section in any case. Check the temperature of the cable, and select the place where the cable is arranged most densely or has the worst heat dissipation or where there is external heat source.
3. Corrosion monitoring. Special instrument shall be used to measure the surrounding soil of adjacent cable lines. If it belongs to anode area, corresponding measures shall be taken to prevent electrolytic corrosion of cable metal sleeve. In the wet soil around the cable line or the soil covered with domestic garbage, the cable metal sleeve often suffers from chemical corrosion and microbial corrosion. According to the measured voltage in the anode area, appropriate cathodic protection measures or drainage devices should be selected.
4. Insulation supervision. The preventive test plan shall be prepared for each cable line according to its importance, and the weak links in the cable line shall be found in time to eliminate the defects that may cause cable accidents. For cable lines with metal sheath insulation requirements to the ground, it is generally necessary to conduct additional DC voltage tests on the outer sheath after the preventive test, so as to timely find and eliminate the defects of the outer sheath.
