Performance I of the hottest aluminum alloy cable

  • Detail

Count the performance of aluminum alloy cable (I)

safety performance of aluminum alloy cable

1. Historical practice has proved

aluminum alloy can make up for the industrial "short board" gold cable. It has been 43 years since it was developed and used in the United States in 1968. This product has been widely used, and the market share of North American countries has reached 80%. After 43 years of practice, it has been proved that the aluminum alloy cable has never experienced any failure and is safe

2. Detection and certification

aluminum alloy cables have passed the inspection and certification of UL in the United States, cul in Canada, Sai global in Australia, and the inspection and certification of various industrial and cultural entertainment cable and wire inspection centers, Wuhan High Voltage Research Institute, national fire protection building material quality supervision and inspection center and other authoritative institutions by China's national military and law enforcement agencies. Aluminum alloy conductors meet the requirements of ACM alloy conductors in Clause 38 of CSA Standard c22.2, And gb12706.1--2008 and iec60502.1, as well as UL standards related to aa8000 series

3. Effect of aluminum alloy composition

◆ after adding rare earth, iron and other components to the aluminum alloy conductor, its conductivity and connection performance are greatly improved. Especially when the conductor is annealed, the addition of iron produces high-strength creep resistance. When the current is overloaded, iron plays a continuous connection role, so that the aluminum alloy conductor will not creep

◆ creep does great harm to the cable. If the cable creeps, its contact point is not pressed tightly enough, and the pressure decreases, which makes the contact resistance increase rapidly. After the current flows, it causes overheating at the joint. If it is not repaired regularly, there will be potential safety hazards. It is very important to solve the problem of cable creep

◆ creep: under the action of temperature, external force and self weight, the metal will slowly produce irreversible permanent deformation with the passage of time. This phenomenon is creep

4. Flame retardant performance

the insulating material of aluminum alloy cable is flame retardant silane cross-linked polyethylene (XLPE), and the self-locking armor structure is adopted in the process. The heat dissipation performance is far better than the sheath of PVC material, which can dissipate heat quickly. After the flame disappears, the flame can be extinguished quickly without delaying other materials. The flame retardant performance is extremely excellent. Aluminum alloy cable adopts new materials and new processes, which can ensure its safer use

electrical performance of aluminum alloy cable

1, cable ampacity

◆ when the sectional area of alloy conductor is 1.5 times that of copper, the electrical performance of alloy conductor and copper conductor are the same, realizing the same ampacity, resistance, and voltage loss

◆ the resistivity of aluminum alloy is between aluminum and copper, slightly higher than aluminum, but lower than copper. Under the premise of the same intercepting flow, the weight of aluminum alloy conductor with the same length is only half of copper. If the conductivity of copper is 100%, the conductivity of alloy conductor is about 61.2%, the specific gravity of alloy is 2.7, and the specific gravity of copper is 8.9, then (8.9/2.7) × (0.612/1) =2, that is, the resistance of copper per unit weight is the same as that of alloy per unit mass. Therefore, when the cross-sectional area of alloy conductor is 1.5 times that of copper, its electrical performance is the same, that is, it achieves the same cross-sectional flow as copper, with a year-on-year increase of 58.3%, resistance, and voltage loss

◆ there are many factors affecting the cut-off flow of power cables, such as; Line characteristics (such as working power, current type, frequency, load factor); The structure of wires and cables (such as the structure of conductor cores, the number of cores, the type of insulating materials, the structure and materials of shielding layers and inner and outer protective layers, and the total outer diameter); Laying conditions (such as laying in air, laying in pipeline, directly buried laying, laying in underground channel, and laying under water); The maximum allowable working temperature of conductive core and surrounding environmental conditions (such as air and soil temperature, soil thermal resistance coefficient, proximity effect of surrounding heat sources), etc

2. Reduce the outer section of the cable

in the production process of aluminum alloy cable, Germany's most advanced compression technology enables the filling coefficient of its conductor to reach 93%. And the aluminum alloy cable adopts silane crosslinked polyethylene, which can far exceed the conventional insulation performance with only 2/3 of the thickness of PVC. The filling coefficient of copper can only reach 80% generally, and PVC is commonly used for insulation, so the outer diameter of aluminum alloy cable can have the same electrical performance as copper only if it does not smell the pungent odor in the traditional plastic processing process, and it is increased by less than 11% on the basis of copper cable. It can be seen that using aluminum alloy cables does not need to change the original pipeline design using copper cables. (generally, the laying pipe size designed by the designer is 150% of the copper cable. Recently, considering the problem of capacity expansion, the laying pipe size has increased to 200% of the copper cable, so it is not a problem to pass through the pipe.)

3. Reduce cable line loss

non magnetic materials will not produce eddy current and can reduce line loss. Aluminum alloy belt armor lock material is non-magnetic material, even if there is three-phase unbalanced current, it will not produce eddy current, which can reduce the loss of the line

Copyright © 2011 JIN SHI