Comprehensive Cable Selection Recommendation Because the construction habits of domestic buildings are different from those in Europe and the United States, the selection of integrated wiring cables cannot be based on the principle of copying foreign standards. China's "General Cabling Engineering Design Specification GB50311-2007" issued in 2007 introduced the cable fire protection and environmental protection rating for the first time. This standard recommends that domestic users choose different levels of fire protection or environmental protection cables according to different occasions. . The selection of fire protection or environmental protection grades for cabling should be based on the actual situation at the site:
1. If the overhead floor or suspended ceiling of the building is in the form of a PVC trunking/pipe in the raised floor or suspended ceiling and an air-conditioning ventilation system is installed, flame-retardant (CMP or OFNP) cables should be used in the raised floor or suspended ceiling; Metal trunking/pipes or flame-retardant PVC trunking/pipes are used in raised floors or suspended ceilings, and optionally fire-rated (CM//CMR/CMP or OFN/OFNR/OFNP) cables may be used. For buildings with environmental requirements such as crowded places (airports, subways, railway stations, hospitals, convention centers, etc.), cables designed for LSZH should be used when designing integrated cabling, and metal trunking with fireproof function should be used. Pipe or flame-retardant PVC trunking/pipes.
2. If the vertical shaft of the vertical shaft of the building is a PVC trunking (line pipe), the vertical shaft (CMR or OFNR) or above cable or optical cable shall be used in the vertical shaft; if the vertical shaft is a metal trunking/duct (or Burning PVC trunking/pipes. Optional vertical flameproof (CM/CMR/CMP or OFN/OFNR/OFNP) cables can be used in vertical shafts.
In summary, green environmental protection has become the consensus of the people. In addition to considering the electrical performance at the moment of integrated wiring construction, long-term investment returns should be considered, such as fire prevention or environmental protection. Low-smoke halogen-free cables are more and more popular because of their high cost performance and environmental friendliness.
As people's living standards are getting higher and higher, and the technology of intelligent and automated equipment is becoming more and more mature, whether the integrated wiring system can resist external invasion and avoid external hazards has become a new target for people's attention. The fire safety of integrated wiring systems has also become a concern.
The cable guard of the data cable is physically divided into two parts: the insulating layer and the jacket. The ability of the cable to have a fireproof function depends primarily on the material of the outermost jacket.
At present, there are two standards in the industry, one is the low-smoke and halogen-free type in Europe and the other is the flame-retardant and fireproof type in North America. Due to the different jacket materials, the prices are different. At present, North American standards are widely used. Cables are classified into four levels: CMX (lowest level), CM, CMR (vertical use), and CMP (forced ventilation). Cables of domestic integrated cabling manufacturers are used. There are more CM grades, and U.S. GCI is one of the few suppliers of integrated wiring products that use CMR grade jackets for all copper cables.
Currently, the cable sheathing materials in the domestic market are mainly divided into three types:
1. Common (PVC) type Most current domestic LAN cabling uses PVC (polyvinyl chloride) materials, PVC is in the polyethylene (PE) to participate in chlorine, to improve the ignition of the cable The advantages of PVC cable are its low price and stable mechanical performance. The disadvantages are low ignition point, rapid flame spread, toxic fumes emitted during combustion, low visibility, and more heat released when burning.
2. Low smoke and halogen-free type (LSZH/LS0H)
In order to comply with more stringent environmental regulations, halogens are not used in the production process of low-smoke and halogen-free (LSZH) cables. When burned, this cable has low toxicity and smoke concentration, which can reduce the emission of toxic gases and the equipment inside the building. Corrosion reduces the number of casualties in case of fire. The flame-retardant low-smoke and halogen-free (LSFRZH/LSFROH) cable incorporates aluminum hydroxide or magnesium hydroxide in the cable sheath. When the cable is once burned, the flame retardancy comes from the water generated during combustion. The burning rate is slower than that of PVC and the burning point is about 150°C. The EU region has particularly stringent requirements for the environmental protection of equipment materials used in buildings, so low-smoke and halogen-free (LSZH) cables are used in Europe in a particularly wide range.
3, fireresistant (fireresistant)
Fireresistant is usually jacketed with PTFE (polytetrafluoroethylene) or FEP (fluorinated ethylene propylene). PTFE or FEP is also a highly efficient insulator. The smoke concentration is very low because fluorine is more fire resistant. The ignition temperature is even higher than that of FRPVC and LSZH, and the ignition point is as high as 800°C. When the FEP cable burns, it releases a colorless, odorless but more toxic hydrogen fluoride than hydrogen chloride. The toxicity of FEP cables is 1.5 times that of PVC cables and 5 times that of halogen-free cables.
1. If the overhead floor or suspended ceiling of the building is in the form of a PVC trunking/pipe in the raised floor or suspended ceiling and an air-conditioning ventilation system is installed, flame-retardant (CMP or OFNP) cables should be used in the raised floor or suspended ceiling; Metal trunking/pipes or flame-retardant PVC trunking/pipes are used in raised floors or suspended ceilings, and optionally fire-rated (CM//CMR/CMP or OFN/OFNR/OFNP) cables may be used. For buildings with environmental requirements such as crowded places (airports, subways, railway stations, hospitals, convention centers, etc.), cables designed for LSZH should be used when designing integrated cabling, and metal trunking with fireproof function should be used. Pipe or flame-retardant PVC trunking/pipes.
2. If the vertical shaft of the vertical shaft of the building is a PVC trunking (line pipe), the vertical shaft (CMR or OFNR) or above cable or optical cable shall be used in the vertical shaft; if the vertical shaft is a metal trunking/duct (or Burning PVC trunking/pipes. Optional vertical flameproof (CM/CMR/CMP or OFN/OFNR/OFNP) cables can be used in vertical shafts.
In summary, green environmental protection has become the consensus of the people. In addition to considering the electrical performance at the moment of integrated wiring construction, long-term investment returns should be considered, such as fire prevention or environmental protection. Low-smoke halogen-free cables are more and more popular because of their high cost performance and environmental friendliness.
As people's living standards are getting higher and higher, and the technology of intelligent and automated equipment is becoming more and more mature, whether the integrated wiring system can resist external invasion and avoid external hazards has become a new target for people's attention. The fire safety of integrated wiring systems has also become a concern.
The cable guard of the data cable is physically divided into two parts: the insulating layer and the jacket. The ability of the cable to have a fireproof function depends primarily on the material of the outermost jacket.
At present, there are two standards in the industry, one is the low-smoke and halogen-free type in Europe and the other is the flame-retardant and fireproof type in North America. Due to the different jacket materials, the prices are different. At present, North American standards are widely used. Cables are classified into four levels: CMX (lowest level), CM, CMR (vertical use), and CMP (forced ventilation). Cables of domestic integrated cabling manufacturers are used. There are more CM grades, and U.S. GCI is one of the few suppliers of integrated wiring products that use CMR grade jackets for all copper cables.
Currently, the cable sheathing materials in the domestic market are mainly divided into three types:
1. Common (PVC) type Most current domestic LAN cabling uses PVC (polyvinyl chloride) materials, PVC is in the polyethylene (PE) to participate in chlorine, to improve the ignition of the cable The advantages of PVC cable are its low price and stable mechanical performance. The disadvantages are low ignition point, rapid flame spread, toxic fumes emitted during combustion, low visibility, and more heat released when burning.
2. Low smoke and halogen-free type (LSZH/LS0H)
In order to comply with more stringent environmental regulations, halogens are not used in the production process of low-smoke and halogen-free (LSZH) cables. When burned, this cable has low toxicity and smoke concentration, which can reduce the emission of toxic gases and the equipment inside the building. Corrosion reduces the number of casualties in case of fire. The flame-retardant low-smoke and halogen-free (LSFRZH/LSFROH) cable incorporates aluminum hydroxide or magnesium hydroxide in the cable sheath. When the cable is once burned, the flame retardancy comes from the water generated during combustion. The burning rate is slower than that of PVC and the burning point is about 150°C. The EU region has particularly stringent requirements for the environmental protection of equipment materials used in buildings, so low-smoke and halogen-free (LSZH) cables are used in Europe in a particularly wide range.
3, fireresistant (fireresistant)
Fireresistant is usually jacketed with PTFE (polytetrafluoroethylene) or FEP (fluorinated ethylene propylene). PTFE or FEP is also a highly efficient insulator. The smoke concentration is very low because fluorine is more fire resistant. The ignition temperature is even higher than that of FRPVC and LSZH, and the ignition point is as high as 800°C. When the FEP cable burns, it releases a colorless, odorless but more toxic hydrogen fluoride than hydrogen chloride. The toxicity of FEP cables is 1.5 times that of PVC cables and 5 times that of halogen-free cables.
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