Low Smoke Zero Halogen Cable refers to the sheathing material in the cable and insulation in wires. These LSF/LSZH cables are made of a thermoplastic compound which emits limited smoke, no halogen as compared to normal cables. Besides, it will not produce any poisonous gases when exposed to fire.
In the event of fire in a building, there is a danger of electric cables burning behind the wall for a long period of time. It then spreads from room to room emitting toxic gases and smoke. In such a scenario, getting out of the building becomes difficult. First of all, while the PVC cable are getting burned, it fill the rooms with thick black smoke which makes it almost impossible to find way for exit. In addition to smoke, poisonous halogen gases are also generated from burning PVC cables. This causes the occupants to lose consciousness and die even before the fire touches the body
In such a situation, LSF/LSZH cables are desirable because it reduces the amount of smoke and poisonous gases generated, which significantly improves the chance of safe escape for the inhabitants. Also, it makes firefighting operations easier as the fire fighters can easily identify and reach the source of fire.
LSF/LSZH cables are popular in places where people live close to cable assemblies and cannot get sufficient ventilation during the fire. These cables find vast application in skyscraper, malls, large commercial spaces, military, railroad, maritime and aerospace. They can also be utilized in the railway & road systems where wires run in underground tunnels.
Since the time fire got discovered, man has been making attempts to protect themselves from its harmful effects. We have always searched for preventive measures to make sure the damage is minimalized. Hence, LSF/LSZH cables were designed keeping in mind the safety of the public, which has become a major concern these days.
We have seen several incidents in the recent past where fire has caused huge damage to people and property. The examples include the fire in The Address hotel near Burj Khalifa and Dubai Mall, Torch Tower Fire in Dubai Marina, and Grenfell Tower in London.
Today, an average time to reach fatal condition is over 3 minutes, but before it was more than 15 minutes. This change has come over because of the increasing use of plastics at home. None the less it is safe to say that smoke and effluent gases are relevant to saving human lives.
LSZH installation can be used in the below applications but are not limited to the below mentions:
- Power cables
- Instrumentation cables
- Control cables
- Building wires
What is the difference between LSF and LSZH cables?
Low Smoke Fume is another term used by some manufacturers for LSZH cables. A manufacturer can give the term as LSF as long as it emits negligible amount of toxic gases & less amount of smoke.
Why LSF/LSZH cables different from normal PVC cable?
LSF/LSZH cables are made of special material with flame retardant property which does not contain halogen. The low smoke zero halogen property makes cable environment protective.
Is there a difference between Flame Retardant Low Smoke (FRLS) and Low Smoke Zero Halogen (LSF/LSZH) cables?
Both are different cables. Low smoke emits clearer and thinner smoke when burning. This helps people to exit the building faster and safely. FRLS cables shall emit a certain amount of toxic gases (< 17% by weight), whereas Zero halogen cables do not emit any toxic gases as it does not contain halogens like fluorine, bromine and chlorine.
Do LSF/LSZH cables cover the same range as the normal power & Instrumentation cables?
The LSZH cables cover all the rated voltage ranging from 300/500V (instrumentation cable), 450/750V Wiring Cables, 600/1000V LV cables & MV cables up to 33kV.
Does these LSF/LSZH cables and wires cost a lot ?
No, there is very small price difference, looking to the cost of project and long time safety, it is negligible.
Testing of LSF/LSZH Cables
Flame Propagation on Single Cables:
This test is carried out as per BS EN 60332-1-2 and IEC 60332-1 to check the resistance of the cables to flame propagation.
Flame Propagation on Multiple Cables:
This test is carried out as per BS EN 60332-3 and IEC 60332-3 to determine the ability of bunched cables to restrain flame propagation.
This test is carried out as per BS EN 61034-2 and IEC 61034-2. The light transmittance will not fall below 70% during the test.
Oxygen and Temperature Index:
This test is carried out as per ASTM D 2863. It determines the oxygen Concentration to support candle-like combustion of LSF Materials.
Acidic (Corrosive) gas evolved (HCL level):
This test is conducted to measure many acidic gases evolved during Combustion of materials from Cables. This test is conducted as per BS EN 60754-1 or IEC 60754-1
Measurement of Ph and Conductivity:
This test determines the degree of acidity of gases evolved during combustion of electric cables. This is done by measuring pH-value and conductivity. This test is conducted as per IEC 60754–2.
Using Fujcab Brand Low Smoke and Fume cables and wires, manufactured by Power Plus Cable, inside buildings reduces the damages to life and property caused by fire. This is achieved as these cables burn slowly and do not propagate fire. They emit very low smoke, fumes and do not produce acid gases during a fire.
Fujcab Brand Low Smoke and Fume cables and wires being flame retardant slow down the spread of fire. This extra time is very critical for the firefighters for putting down the fire and for rescuing the occupants trapped. It prevents loss of human life by panic and suffocation.