Many people know about low-voltage cables and high-voltage cables, but very few people know about medium-voltage cables. The voltage range of medium-voltage cables is between 6KV and 33KV. Its actual production and application fields include petrochemical, transportation, wastewater treatment, and food processing. etc. They are also important application cable types.
Feature of Medium Voltage Cable
With the economic development in recent years, the importance of medium-voltage cables has gradually become prominent, and the demand for medium-voltage cables in all walks of life is also increasing. Because of their characteristics, medium-voltage cables have different sizes and types. For special requirements, the structure of medium-voltage cables is much more complicated than that of low-voltage cables. What’s more, the materials and production processes used are different. And the insulation layer of medium voltage cables is generally composed of three layers, conductor shielding layer, insulating material, and insulating shielding layer.
And the raw material of medium voltage cables is also different, even though the insulation has the same identification as low voltage cables ( like XLPE), the raw material itself is different to ensure purer insulation. Core identification using colored masterbatches for low voltage cables is not permitted.
Failure Problem of Medium Voltage Cable
Medium voltage cables also need to pay special attention to the common failure problems in use. Most of the reasons are caused by the aging of the cable infrastructure. Generally, partial discharge is actually a harbinger of failure, because it provides evidence that the cable is beginning to deteriorate, which will cause the failure to power down later.
Cable aging typically begins with reducing electrical resistance to affect cable insulation. It is a key indicator of defects including moisture or air pockets, water trees, electrical trees, and other issues. Additionally, the breakaway jacket can be affected by aging, increasing the risk of reaction or corrosion, which can cause problems later in service.
Therefore, when choosing cables, you should buy qualified and high-quality products, because low-quality cables often have the problem of premature aging, and aging is the root cause of many failure problems.