In all fire disasters, fire smoke, heat and toxic fumes are the main obstacles to safe evacuation of a building or area. A major contribution towards overcoming these hazards is the use of fire resistant and non-halogenated cables.
Ⅰ.Classification of fire resistant cables
Definition of fire-resistant cables: Under the specified test conditions, the specimen is burned, and after the withdrawal of the test fire source, the flame spreads only within a limited range, and the residual flame or residual burns are within a limited time.
Residual flame or residual burns in the limited time can extinguish the cable, in the case of fire may be burned and can not run, but can prevent the spread of fire.
In layman's terms, in case of fire, the wire can limit the burning to a localized range, do not produce the spread of other equipment, to avoid causing greater losses.
avoid causing greater losses.
(1) Flame Retardant Cables
Flame Retardant Cables are characterized by delaying the spread of flame along the cable so that the fire does not expand. Because of its low cost, it is a large number of cable varieties used in fire protection cables. Whether it is a single cable or a bundle of laying conditions, the cable was burned when the spread of flame can be controlled within a certain range, so you can avoid major disasters caused by the cable fire delayed combustion, thus improving the level of fire protection cable lines.
(2) Fire resistant cables (Fire Resistant Cables)
Fire Resistant Cables can maintain normal operation for a certain period of time in the case of flame combustion, and can maintain the integrity of the line (Circuit Intergrity) Fire Resistant Cables produce less acidic fumes during combustion, and the fire-resistant and flame-retardant properties are greatly improved, especially in the case of combustion, accompanied by water showers and mechanical strikes and vibrations, the cables can still keep the line running intact.
Ⅱ.Fire Alarm Cable Application Scenario
Fire Alarm Cable is usually called Power Limted Fire Alarm Cable (power limiting fire alarm circuit cable), which is mainly used in fire safety circuits, such as: high-rise buildings, subways, large power stations and important industrial and mining enterprises of the fire protection system, emergency lighting systems, life-saving systems, as well as industrial, commercial and residential buildings, public broadcasting and emergency voice communication systems. Emergency voice communication systems in industrial, commercial and residential buildings.
Fire Alarm Cable The standards implemented in each country (region) are not the same, and there are both cables with flame retardant requirements and cables with fire-resistant requirements.
Ⅲ.Fire Alarm Cable examines the following characteristics of cables:
(1) long-term cable integrity (fire resistance)
When a fire occurs, within a certain period of time, can continue to maintain the normal operation of the cable line (i.e., in the event of a fire can still maintain the power supply to provide protection for fire fighting and personnel escape).
(2)Reduce the characteristics of fire propagation
That is: when the fire is found, the cable can extinguish itself within the specified time, which can prevent the spread of fire. This point, the main assessment of the cable's flame retardant grade, the higher the flame retardant grade, the cable burning, a little that is extinguished.
(3)the minimum smoke emissions
That is: when the fire is found, the cable burning, the determination of smoke density, the main emphasis here is on low-smoke non-halogen (LSZH) materials, the main assessment index is the smoke density (minimum transmittance).
(4)Corrosion and toxicity index
That is: Zero Halogen (Zero Halogen) low-smoke halogen-free materials do not contain halogens, combustion produces a very small amount of smoke, corrosivity and toxicity is also low, thus reducing the damage to the human body, instruments and equipment, and is conducive to the occurrence of a fire in a timely manner to rescue.
Therefore, the ideal fire alarm cable can maintain circuit integrity in the short term once a fire has been detected, ensuring maximum safe evacuation of personnel and producing no harmful effects such as toxic gases or smoke.
