What is LSZH Cable?
LSZH stands for Low Smoke Zero Halogen. It is a special type of electric cable. You might also see people call it LSOH or LS0H. It is all about safety. Normal cables have chemicals inside. When they burn, these chemicals make bad smoke. This smoke is black and thick. It also has toxic gas. LSZH cable is different. It is made from special materials. When it burns, it makes very little smoke. The smoke is not black. It is hard to see. Also, it does not release toxic gas. This keeps people safe during a fire. It helps them breathe. It also helps them see the way out.
Why Choose LSZH Over PVC?
PVC is the most common cable material. It is cheap. But it is dangerous in a fire. PVC has chlorine. Chlorine is a type of halogen. When PVC burns, it makes hydrochloric acid. This acid hurts your lungs. It also hurts electronic machines. LSZH cable has no halogens. It has no chlorine. It has no fluorine. It has no bromine. So, it is non-toxic. This is why buildings choose LSZH. It is safer for humans. It is also safer for equipment. If a fire starts, the acid gas will not destroy computers or servers. It saves money on repairs later. It follows strict green building rules. Many countries require LSZH now.
Key Technical Specifications
Here are the hard numbers for our LSZH cables. We make them to international standards. You can see the details below.
Voltage Ratings
We usually make these cables for low and medium voltage. The standard ratings are 600 Volts. We also do 1000 Volts (1kV). Some types go up to 35kV. For data cables, it is usually 300 Volts. Always check the print on the cable jacket. It will say the voltage.
Temperature Range
These cables handle heat well. They work in cold places too. The conductor gets hot when working. The max temperature is usually 90°C. If there is a short circuit, it can handle 250°C for a short time. For installation, do not bend it if it is below 0°C. It might crack. The operating range is -40°C to 90°C.
Fire Performance Standards
This is the most important part. We test our cables strictly.
- IEC 60332-1: This tests if the cable stops burning when the fire source is gone.
- IEC 61034-2: This measures the smoke. Our cable has a light transmittance of over 60%. That means you can see through the smoke.
- IEC 60754-2: This tests the gas acidity. Our pH value is over 4.3. The conductivity is under 10 μS/mm. This means the gas is not corrosive.
Material Makeup
- Conductor: We use plain annealed copper. It is 99.9% pure. It conducts electricity best. We can also use stranded copper for flexibility.
- Insulation: We use XLPE (Cross-linked Polyethylene). It is strong. It does not melt easily.
- Bedding/Sheath: This is the LSZH mix. It uses magnesium hydroxide or aluminum hydroxide. These minerals stop the fire. They release water when hot. This cools the cable down.
Where to Use LSZH Cable?
You need this cable in crowded places. You need it where air flow is limited. It is the law in many public buildings.
Public Transport Systems
Subways use a lot of LSZH cable. Trains are underground. If a fire happens, smoke kills people fast. LSZH keeps the tunnel clear. Airports use it too. It is in the terminals and runways.
High-Rise Buildings
Skyscrapers have many people. Evacuation takes time. The cable must not add poison to the air. It is used in stairwells. It is used in elevators. It is used in hallways.
Data Centers and Hospitals
Hospitals have sick people. They cannot run from smoke. Computers in server rooms hate acid. Acid ruins the circuit boards. LSZH protects the data. It protects the patients. Schools and universities also use it for safety.
Industrial Plants
Oil rigs and chemical plants are risky. They have explosive gas. LSZH is safer there. It does not make the explosion worse.
How We Test Quality
We do not just talk about safety. We prove it. Our factory has a big lab. We test every batch of cables.
First, we check the copper. We measure the diameter. We check if it is pure. If the copper is bad, the cable gets hot.
Second, we test the insulation. We use high voltage to check for holes. If there is a hole, it will spark. We reject any cable with holes.
Third, we do the flame test. We hang a cable sample. We light a fire under it. We time how long it burns. We measure the smoke density. We collect the gas. We check the pH level in the lab. If it fails one test, we stop the line. We fix the problem. Then we test again. This ensures you get a safe product.
Installation Tips for Electricians
Installing LSZH is a bit different from PVC. You need to be careful.
Bending Radius
LSZH is stiffer. It has a harder jacket. Do not bend it too sharp. The rule is 12 times the cable diameter. If you bend it too much, the inside copper might break. Or the jacket might crack.
Stripping the Jacket
Be gentle when stripping the outer skin. Do not use a dull knife. A dull knife nicks the insulation under the skin. If you nick the XLPE, water can get in. This causes failure later. Use sharp tools.
Termination
You can use standard lugs. But make sure the connector is tight. LSZH does not shrink like PVC when heated. So, use heat shrink tubes that match LSZH. They must also be low smoke. Do not mix PVC and LSZH parts. It ruins the fire rating.
Storage
Keep the cable dry. The LSZH material absorbs water a little bit. If it gets wet for a long time, it is hard to strip. Store it in a cool, dry place. Do not put heavy things on top of the reels. It can squash the shape.
Frequently Asked Questions
Is LSZH cable waterproof?
No, not by itself. The standard LSZH jacket resists water. But it is not 100% waterproof. If you need it underground or in water, add an armor. Or add a separate black PE outer sheath. We call this “Double Sheath” cable.
Can I bury LSZH cable directly?
It depends. Standard LSZH is for indoor use. UV rays from the sun damage it over time. If you bury it, the soil moves. This can wear the jacket. For direct burial, use armored LSZH. The steel tape protects it from rocks and pressure.
Does it cost more than PVC?
Yes. The raw materials cost more. Magnesium hydroxide is expensive. The process is harder. But the safety value is high. In a fire, PVC cable costs lives. LSZH saves them. The price difference is worth it for public safety.
What colors are available?
LSZH is naturally translucent. But we add color. The most common is orange. We also do red, blue, black, and white. Orange is popular for fire alarm circuits. Black is for power. We can print text on the jacket. We print the voltage, the size, and our brand name. We do this every meter.
How long does it last?
It lasts as long as PVC. Usually 30 years indoors. If it gets too hot often, life gets shorter. Keep it under 90°C. If you run it at max heat all day, it will age faster. Always follow the ampacity charts. Do not overload the cable.