How to Choose Medium Voltage Cable?

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. They are also important application cable types.

Development 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. With special requirements, the structure of medium-voltage cables is much more complicated than that of low-voltage cables. Moreover, the materials and production processes used are different. The insulation layer of medium voltage cables is generally composed of three layers, conductor shielding layer, insulating material, and insulating shielding layer.

Materials of Medium Voltage Cable

And the raw material of medium voltage cables is also different, even though the insulation has the same identification as low voltage cables (XLPE), the raw material itself is different to ensure a purer insulation. Core identification using coloured masterbatches for low voltage cables is not permitted.

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. Then they will cause malfunctions and failures, and power outages 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, should you buy qualified, high-quality products, because low-quality cables often have the problem of premature aging, and aging is the root cause of many failure problems.