Power cable safety precautions in heavy rainfall weather

2023-07-31

In recent days, there has been a large amount of precipitation across the country, with the arrival of heavy rainfall weather, electricity safety has also been affected. Recently, the relative humidity in individual areas reached more than 90%, in such a high-humidity environment, how to prevent wire and cable safety accidents is an important issue.

The impact of continuous rainy weather on power construction and domestic electricity consumption:
Impact 1: Many places in switchgear rely on air gap insulation, and the high humidity environment reduces the insulation performance of air.
Impact 2: The moisture in the air adheres to the surface of the insulating material, reducing the insulation resistance of the electrical equipment, especially the equipment that has been used for a long time, because there is dust accumulation inside to absorb moisture, the humidity will be more serious, and the insulation resistance will be lower. The leakage current of the equipment is greatly increased, and even causes insulation breakdown, resulting in accidents. In particular, high-voltage power facilities are more likely to produce high-voltage discharge.
Impact 3: Moist air is conducive to mold growth. When the temperature is 25 to 30 degrees and the relative humidity is 75% to 95%, it is a good condition for mold growth. Therefore, if the ventilation is not good, it will accelerate the growth rate of mold. The mold contains a lot of moisture, which greatly reduces the insulation performance of the equipment. For some porous insulating materials, mold roots can also penetrate into the interior of the material, causing insulation breakdown. At the same time, the acidic substances secreted during the metabolism of mold corrode the insulation materials, which will also reduce the insulation performance of the equipment.
Impact 4: Humid air can also rust conductive metals, magnetic conductive silicon steel sheets, and metal shells in power equipment, which will reduce the performance and service life of the equipment, and even cause electrical failures.

Construction site construction precautions during rain:
Item 1: In strict accordance with the "construction site temporary electricity safety technical specifications" in the construction of the safety measures.
Item 2: All kinds of open-air electrical equipment should be placed in a higher dry place; Temporary electricity and cables should be laid overhead, and do not soak cables in rain.
Item 3: The main distribution box, distribution box and switch box have reliable rain protection measures, and the welding machine is equipped with rain protection cover.
Item 4: Before the rain period, check whether the lighting and power lines are mixed, leakage phenomenon, whether the pole is corroded, buried loose, etc., to prevent electric shock.
Item 5: Before the rainy season, it is necessary to check whether all construction electrical equipment has good grounding and zero protection, and whether there is a leakage protector installed to ensure that protective measures are implemented and reliable. Whether the leakage protection device is sensitive, and whether the wire insulation joint is good.
Item 6: Before the rainstorm weather, the temporary power supply of the construction site is cut off except for lighting, drainage and emergency power.
Item 7: On-site construction cables should be centrally arranged to prevent disorder, timely replacement of aging or damaged cables with insulation coats, and timely recovery of unnecessary cables.
Item 8: If the high metal frame and other elevated facilities at the construction site are outside the protection range of the lightning protection devices of the adjacent buildings and structures, the lightning protection devices shall be set up according to the regulations to ensure the equipment and personal safety.

Source: China Cable Network