High Voltage HT XLPE Cables: What Are They?
Are you looking for power transmission cables for your high-voltage application? HT XLPE cables are the way to go. They provide high efficiency with excellent durability while ensuring safety. This article provides a detailed guide on high-voltage HT XLPE cables and helps you select the right cable for your application.
What are High Voltage HT XLPE cables?
High Voltage HT XLPE cables are insulated cables that are designed to safely carry high-voltage electrical current over long distances. They are often used in transmission lines, substations and other electrical infrastructure.
Materials Used to Manufacture High Voltage HT XLPE Cables
High Voltage HT XLPE Cables are composed of the inner conductive core with an insulating layer, followed by an inner sheath, armour and outer sheathing.
The conductor is made of either copper or aluminium, covered by an insulating layer.
The most distinctive component of XLPE cables is the insulating layer, which is typically made of cross-linked polyethene (XLPE). This XLPE insulation is strong and resistant to wear and tear, making it ideal for long-term use. Apart from that, it is also resistant to most chemicals, allowing it to be used in applications where other materials would be prone to damage.
The XLPE layer is covered by the inner sheathing, generally made of PVC. This sheathing is then followed by metal armour which provides strength and durability to the cable.
The outer jacket is available in a variety of materials, including PVC, rubber and EPDM. The jacket also shields the cable from env ironmental elements like moisture, extreme temperatures and UV radiation.
Things to consider when buying HT XLPE cables
To ensure efficient transmission of the intended power while maintaining the safety of the cable, it is important to consider your requirements. It is critical to select the best-suited HT XLPE cable based on the size of the conductor, voltage grade, number of cores and type of conductor of the cable.
Size of the conductor
The size of the conductor of a High Voltage HT XLPE cable determines the amount of current it can carry. The larger the size of the conductor, the more current it can safely handle.
Generally, a 12-22kV 95 sq. mm. single-core copper conductor XLPE cable has a current carrying capacity of around 230 to 345 amps. Compared to that, a 1000 sq. mm. single-core copper conductor XLPE cable has a current carrying capacity of around 660 to 1240 amps.
Voltage grade of the cable
The voltage grade of a High Voltage HT XLPE cable indicates the maximum working voltage that the cable can sustain without breaking down. To ensure safe operation, it is advised to select a cable with a voltage grade higher than the expected operating voltage. High Voltage HT XLPE cables are available in a range of voltage grades, from 6kV to 33kV, and some special grades can even go as high as 66kV.
Number of cores in the cable
The number of cores in a High Voltage HT XLPE Cable refers to the number of individual conductors in the cable. Single-core cables are typically used for short-distance, low-voltage applications such as between a transformer and a switchboard, whereas three-core and four-core cables are typically used for longer-distance, higher-voltage applications such as between two substations.
Type of conductor
There are two types of conductors available in HT XLPE cables: Copper conductor and aluminium conductor.
Copper has a high electrical and thermal conductivity, which makes it very efficient for transmitting electricity while minimising the risk of overheating. Furthermore, corrosion resistant property of copper makes it a great choice for long-term use in harsh environments.
On the other hand, aluminium is cost-effective, making it a great option for budget-conscious projects. However, aluminium is comparatively less efficient and is more prone to oxidation and corrosion than copper. As a result, it is not suitable for applications where efficient transmission of power and corrosion resistance are of utmost importance.
Benefits of using high voltage XLPE cables over PVC cables
The difference between an XLPE cable and a PVC cable lies in the insulating material used to cover the conductors of each core of the cable. However, this simple difference provides various advantages to XLPE cables over PVC cables.
The use of XLPE offers improved electrical performance, greater flexibility and enhanced safety. The improved electrical performance of HT XLPE cables allows for more efficient energy transfer.
Additionally, their low capacitance and inductance values result in minimal voltage drop and impedance, allowing them to deliver power with fewer energy losses. As a result, XLPE cables offer around 25-30% higher current carrying capacity than PVC cables.
Finally, XLPE is comparatively more durable than PVC, thereby providing better strength to the cable with an operating temperature range of around 90℃ to -90℃.
Raise Quotation for HT XLPE Cables online at L&T-SuFin
High Voltage HT XLPE Cables are highly recommended for applications where high voltage current is to be transmitted over a long distance with minimal energy loss. However, you need to analyse your requirement and select the best-suited cable to minimise cost while ensuring safety. L&T-SuFin offers a wide range of HT XLPE Cables to choose from for all your applications. Their affordable prices and excellent logistic support make them the leading marketplace in the domain.
XLPE Cable Specifications: What To Look For in A Quality Cable
Looking for a quality HT XLPE cable but not sure what specifications to consider? This article provides a detailed guide about the specifications of XLPE cables in India 2023. It also helps you select the right one for your application.
Features and specifications of XLPE cables
HT XLPE cables are commonly used for high-voltage applications where electric power is to be delivered over a long distance with high efficiency. However, there are various specifications that you need to consider to select the right cable for your application.
Safety standards
The HL XLPE cables in India are governed by IS: 8130 (1984) and IS: 7098 standards.IS: 8130 (1984) governs the quality of conductors used in the cable. IS:7098 governs the quality of the conductor screen, insulation used, armour and the inner and outer sheath.
Therefore, when buying HT XLPE cable, look for the one confirming these standards.
Voltage rating
High Voltage HT XLPE cables are available in different voltage ratings, ranging from 3.3 kV to 33 kV. Apart from this, some manufacturers also produce HT XLPE cables with a voltage rating of 66 kV. Generally, it is advised to use a cable that has a voltage rating higher than your expected load. However, the cost of the cable increases with the increase in the voltage rating. Therefore, it is advised to identify your requirement and select the cable with the most appropriate voltage rating for your application.
Number of cores
Typically, HT XLPE cables are available in 1, 3 or 4 cores. The number of cores you choose will depend on the application and the power requirements of the system. Single-core cables are the most basic type of HT XLPE cables. They are typically used in lighting circuit wiring, multi-core cables are ideal for high-voltage applications. Applications such as power transmission, electrical infrastructures, industrial machinery, agricultural equipment, etc.
Type of conductor
When choosing an HT XLPE cable for a particular application, one of the key factors to consider is the type of conductor used.
The conductor of an HT XLPE cable is typically either copper or aluminium, encased in a jacket of insulation. Copper is typically more expensive than aluminium, but it has superior thermal and electrical conductivity. In addition, copper has higher tensile strength and flexibility, which makes it ideal for longer runs of cable. On the other hand, aluminium is cheaper and is suitable for cost-sensitive applications where high efficiency is not of utmost importance.
Size of conductor
The size of the conductor is measured in terms of cross-sectional area, commonly expressed in terms of Sq.mm. The larger the size of the conductor, the higher the current carrying capacity and the higher the cost.
Generally, single-core conductors are available in sizes ranging from 35 Sq.mm to 1000 Sq.mm, whereas multi-core HT XLPE cables have a conductor size ranging from 35 Sq. mm to 400 Sq. mm.
Armour type
Armour is a metal protective covering that provides stiffness and prevents the HT XLPE cable from mechanical damage. Galvanized steel strip armour is commonly used in multi-core cables. However, you can also find aluminium and copper armours for enhanced flexibility.
Apart from protection, armour cables, such as flat-strip aluminium armour also reduce hysteresis losses and improve the efficiency of the cable.
Usage and applications of XLPE cable
Outdoor Applications
HT XLPE Cables are highly resistant to extreme temperatures, ranging from -50°C up to 150°C. This makes them ideal for applications where temperature fluctuations are common, such as in outdoor applications with extreme temperature conditions.
Underground installation
HT XLPE Cables are incredibly durable and can last up to 50 years without needing replacement. This makes them an ideal option for areas where the cables will be subjected to extreme conditions. This is also ideal where frequent repairs cannot be performed, such as in underground or marine applications.
Industrial applications
HT XLPE Cables are rated to operate up to a maximum temperature of 90℃. They can withstand short circuit temperatures of up to 250℃. In addition, these cables are generally flame retardant and self-extinguishing, which minimises the risk of fire.
This makes it ideal for aerospace and other industrial applications where high current capacity is required, without compromising safety.
High-power transmission applications
HT XLPE Cables can transmit high-voltage electrical power over long distances, making them ideal for electricity transmission from one power station to another.
Things to consider while buying XLPE cable
Every XLPE cable has a code that determines its specifications, such as the type of conductor, insulation, armour and outer sheathing used in the cable.
The table below provides information about the different elements of the code.
| Code | Constituent |
| A | Aluminium conductor |
| C | Copper conductor |
| 2X | XLPE Insulation |
| W | Round Steel Armour |
| F | Flat steel strip armour |
| Y | PVC outer sheathing |
For example, an HT XLPE cable with code "A2XFY" has an aluminium conductor, with XLPE insulation, flat steel strip armour and a PVC outer sheathing. Therefore, look for the code and select the best-suited cable for your application.
Apart from that, always look for the cables that comply with the Indian standards for XLPE cables, like IS: 8130 (1984) and IS: 7098. This ensures the safety and reliability of the cable.
Buy XLPE cables online at L&T-SuFin
HT XLPE cables are specified based on various factors like the type of conductor, number of cores, armour, standards, etc., and selecting the right cable based on these specifications will help you minimise the cost while ensuring efficiency and safety. L&T-SuFin is a leading marketplace in India with a variety of XLPE cables at affordable prices and provides detailed information about their specifications. Have a look.