What is an Underground Cable?
An underground cable is a special wire. It carries electricity under the ground. We use it in cities. We also use it in factories. Normal wires are in the air. But air wires break easily in storms. Underground cables are safe. They do not take up space above ground. The look of the city is clean.
This cable has many layers. Each layer has a job. The center is the metal wire. It moves the power. Around it is insulation. It stops the power from leaking. Then there is armor. It protects the cable from rocks and water. This design makes the cable last a long time. It can work for 30 years or more.
Why Choose Our Underground Cables?
We make cables for a long life. Our factory checks every meter. We use high-quality copper. Copper moves electricity better than aluminum. It has less heat. This saves energy. Our insulation is XLPE. It stands high heat. It does not get old easily.
Installation is easy. We put a pull rope in the pipe. You can pull the cable fast. You do not need big machines. Our cable bends well. It fits in small pipes. It is safe for workers. It is safe for people walking on the street.
Detailed Construction of the Cable
1. Conductor (The Core)
The core is made of copper. We use 99.9% pure copper. It is solid or stranded. Stranded is flexible. It is easy to bend. The conductor carries the current. We make it according to IEC standards. You can choose the size. It ranges from 50mm² to 1000mm².
2. Insulation Layer
We use Cross-linked Polyethylene (XLPE). This is a special plastic. It is very strong. It handles high voltage. It does not melt at 90 degrees Celsius. If there is a short circuit, it handles 250 degrees. It is much better than PVC. PVC melts too fast. XLPE keeps the power on.
3. Metallic Screen
Around the insulation, there is a screen. It is usually copper wire or tape. This screen is important. It makes the electric field even. It stops static build-up. If the cable leaks, this screen sends the current to the ground. It trips the breaker. This stops fires.
4. Bedding
Over the screen, we add a layer of PVC. It is like a pillow. It is soft. It protects the screen. It stops the armor from hurting the screen. This layer fills the gaps. It makes the cable round.
5. Armor (The Shield)
This is the strong part. We use steel wire or steel tape. It protects the cable. If someone digs, the armor stops the shovel. If a rock falls, the cable does not break. It is for mechanical protection. You can choose single armor or double armor. Double is for rough ground.
6. Outer Sheath
The outside is black PVC or PE. PE is polyethylene. It resists water. It resists chemicals in the soil. It also resists UV light if part of it is in the sun. The color is usually black. We can add yellow stripes. The stripes warn diggers. It says “Danger Cable” without words.
Technical Specifications Table
| Parameter | Value | Note |
|---|---|---|
| Voltage Level | 8.7/15kV, 12/20kV, 18/30kV, 26/35kV | Other voltages on request |
| Standard | IEC 60502-2 / BS 5467 / ASTM | International standard |
| Conductor | Copper (Cu) or Aluminum (Al) | Class 1 or Class 2 |
| Insulation | XLPE (Cross-linked Polyethylene) | White or Black core |
| Armor | SWA (Steel Wire Armor) or STA (Steel Tape) | Galvanized steel |
| Sheath | PVC (Polyvinyl Chloride) | Black color, flame retardant |
| Operating Temp | -15°C to +90°C | Max emergency temp: 250°C |
| Min Bending Radius | 12 x Overall Diameter | For single core |
| Laying Method | Trench, Duct, Direct Burial | Not for aerial use |
Where Do We Use This Cable?
Urban Power Grids
Cities have many buildings. They need a lot of power. We cannot put wires on poles everywhere. It looks messy. It is dangerous in wind. We dig a trench. We put the cable in pipes. We cover it with sand. Then we put concrete slabs on top. The city looks nice. The lights stay on.
Industrial Zones
Factories use big machines. They need high voltage. Usually 11kV or 33kV. The ground in factories is hard. There are trucks moving. We need strong armor. Our SWA cable is perfect. It resists crushing. It resists oil. It works in dirty environments.
Renewable Energy
Solar farms and wind farms are outside. The cables connect to the grid. The distance is long. We need cables that do not lose power. Our cable has low resistance. It moves power far away. It is buried to save land for farming.
Ports and Airports
These places need reliable power. If the power cuts, it is a big problem. Our cable is very reliable. We use thick insulation. We use water-blocking tape. If the pipe breaks, water does not go far. It keeps the system running.
Installation Guide for Buyers
Step 1: Dig the Trench
Dig a path for the cable. Make it deep enough. Usually 700mm to 1000mm deep. The bottom must be soft soil. No big rocks. Put 100mm of sand at the bottom.
Step 2: Lay the Pipes
Put PVC or HDPE pipes in the trench. These pipes protect the cable. It is easy to change the cable later. Leave a manhole every 50 meters.
Step 3: Pull the Cable
Use a winch to pull the cable. Do not pull too hard. The force must be on the conductor. Do not pull on the insulation. Use a swivel joint. It stops the cable from twisting.
Step 4: Connect the Joints
When two cables meet, use a joint kit. It is like a big connector. It must be waterproof. It must be sealed tight. Use a heat gun or cold shrink tubes.
Step 5: Backfill
Cover the pipe with sand. Then put red warning tape. It warns future diggers. Finally, fill the dirt. Put concrete covers on top.
Packing and Shipping
We pack the cable on wooden drums. The drum is strong. It is fumigated for export. The cable end is sealed. It stops moisture. We put a cap on it. We wrap the outside with plastic film.
We can ship by sea. It is the cheapest way. It takes 20 to 40 days. We can also ship by train to Europe. It is faster than sea. We have insurance. If the drum breaks, we pay.
Frequently Asked Questions
Q: Can I get a sample?
A: Yes. We can send a short piece. It is 1 meter long. You pay for the shipping.
Q: What is the lead time?
A: It depends on the size. Normal sizes are in stock. We ship in 7 days. Big orders take 15 days.
Q: Do you have a test report?
A: Yes. Every batch has a test report. We test voltage. We test resistance. We send you the PDF.
Q: Can you print my logo?
A: Yes. We print on the cable surface. We also print on the drum. It is free for big orders.
Q: What is the warranty?
A: We guarantee the quality for 2 years. If it breaks because of making, we replace it.
Why Buy From Us?
We are a real factory. We are not a trading company. You get a better price. We control the copper quality. We control the XLPE material. We do not use cheap recycled plastic.
Our engineers have 20 years of experience. They solve problems fast. If you have a special need, we design it. We make the cable exactly for your project. We speak simple English. We reply fast. Send us an email today. Get a quote tomorrow.