Medium Voltage Cables: 4 things you must to know

A medium-voltage (MV) cable is an appropriate choice for power frequency-rated voltage distribution systems with a voltage range of 6-35 kV. Furthermore, the cable is suitable for deployment in a variety of environments, including those with elevated average operating temperatures. Additionally, its straightforward structure, compact outer diameter, lightweight composition, and the absence of a laying drop contribute to its user-friendliness.

Moreover, the Medium Voltage Cables employ a dry chemical cross-linking method. This cross-linking method utilizes polyethylene molecules that are linearly inserted into a spatially reticulated structure. Additionally, the thermoplastic polyethylene molecular structure is converted into thermosetting cross-linking polyethylene, resulting in an excellent combination of mechanical, electrical, and heat aging properties.

Why are Mv Cables shielded?

The use of shielding is a common practice in the field of medium voltage cable engineering. The purpose of this technique is to prevent electrical interference and to minimize the risk of electromagnetic interference (EMI) and radio frequency interference (RFI). The application of a shielding layer serves to regulate the electric fields within the cable, thereby reducing the likelihood of electromagnetic radiation and the impact of external electromagnetic fields on the signal integrity of the cable. Furthermore, the incorporation of a shielding layer can mitigate the risk of electrical failure and enhance the cable's resilience to environmental factors, thus improving the overall safety and reliability of the cable system. In summary, the use of shielded medium voltage cables facilitates the maintenance of electrical signal integrity, minimizes the risk of interference, and ensures the safe and reliable operation of distribution systems.

Copper Wire Screen’s function in MV Cable

The copper wire shielding of medium voltage cables mainly has the following functions:

Electromagnetic shielding: Copper wire shielding can effectively reduce electromagnetic interference, prevent external electromagnetic fields from interfering with signals or power transmission inside the cable, and improve the cable’s anti-interference ability.

Protective conductor: Copper wire shielding can provide an additional layer of protection to prevent external physical damage or chemical corrosion from affecting the cable conductor and extend the service life of the cable.Safety protection: Copper wire shielding can provide a certain degree of safety protection, reduce the interference from the outside of the cable to the inside, and reduce the risk of electric shock.

In general, copper wire shielding plays a role in protecting conductors, reducing electromagnetic interference and improving safety in medium voltage cables.

How do I choose MV Cable?

The appropriate selection of medium-voltage cables necessitates an evaluation of the following factors:

The usage environment and the requirements that must be met are of paramount importance. Primarily, it is essential to consider the usage environment of medium-voltage cables, encompassing factors such as temperature, humidity, chemical substances, and other variables. Additionally, cable safety, environmental protection, and other requirements must be taken into account.

The electrical performance of the medium-voltage cable must be considered. In order to ensure optimal power transmission, it is essential to consider the electrical performance of the medium-voltage cable, including its voltage resistance, resistance, and insulation performance, among other factors.

The mechanical properties of the medium-voltage cable must also be taken into account. It is essential to consider the mechanical properties of medium-voltage cables, including tensile strength, abrasion resistance, pressure resistance, and so forth, in order to adapt them to different laying environments and usage conditions.

The following installation requirements must be taken into account: The selection of an appropriate cable type and structure is contingent upon the laying method of medium-voltage cables, the installation environment, and other requirements.

In order to ensure the quality and performance of medium-voltage cables are recognized, it is essential to select cables that meet international standards. It is advisable to select medium-voltage cables that comply with international standards in order to guarantee that their quality and performance are acknowledged.

Cost-effectiveness is a crucial factor to be considered. It is essential to undertake a comprehensive evaluation of the performance, quality, and price of medium-voltage cables, with a view to selecting products that offer the greatest cost-effectiveness.

In selecting medium-voltage cables, it is advisable to consult with professional electrical engineers or cable suppliers in order to identify suitable products that align with specific needs and circumstances.

How to select mv cable size?

The selection of an appropriate medium-voltage (MV) cable size necessitates the consideration of several factors to ensure the safe and efficient transmission of power. The following factors are of particular importance when selecting an MV cable size:

The current carrying capacity is a crucial factor to consider when selecting an MV cable size. It is essential to ascertain the maximum current that the cable is required to convey. This is contingent upon the power load and the system voltage.

It is also necessary to calculate the acceptable voltage drop over the length of the cable. It may be necessary to utilise a larger cable size in order to minimise voltage drop, particularly in instances where the cable run is of a considerable length.

Environmental Conditions: It is essential to consider the environmental factors, such as temperature, moisture, and any specific requirements for outdoor or underground installation. It is essential to select a cable with insulation and jacketing that are compatible with the intended environment.

Short-Circuit Rating: It is imperative to ascertain that the selected cable size is capable of safely accommodating short-circuit currents without sustaining damage.

It is essential to ensure compliance with the relevant standards. It is essential to select an MV cable size that meets the requirements of relevant industry standards and regulations for medium voltage power transmission.

It is also important to consider future expansion requirements. In the event that there is a possibility of system expansion or increased power demand in the future, it would be prudent to select a cable size that can accommodate potential growth.

It is advisable to seek the counsel of a duly qualified electrical engineer or a professional versed in the intricacies of medium voltage power systems to ascertain that the selected cable size is in alignment with the specific requirements of the intended application.

By exercising due diligence in these matters and seeking the guidance of a duly qualified professional, it is possible to select an MV cable size that is well-suited to the medium voltage power transmission needs, thereby ensuring safety, reliability, and compliance with industry standards.