From the characteristics of aluminum alloy cable, aluminum alloy cable has natural defects in fire protection and corrosion protection.
Corrosion resistance, 8000 series aluminum alloy is inferior to aluminum
GB/T19292.2-2003 standard 4 in table 1: aluminum alloy corrosion resistance worse than worse to copper, aluminum, this is because the aluminum alloy cable joined the magnesium, copper, zinc, iron, so prone to local corrosion, such as stress corrosion cracking and exfoliation corrosion, intergranular corrosion, and 8000 series aluminum alloy belongs to easy corrosion formula, aluminum alloy cable increases the heat treatment process, easy to cause physical condition is not uniform, more easier than aluminium cable corrosion. At present, the aluminum alloy used in China is basically 8000 aluminum alloy series.
Temperature resistance, aluminum alloy bigger difference than copper
Copper has a melting point of 1080 ℃ and the aluminum and aluminum alloy is 660 ℃, so the copper conductor is fire-resistant cable better choice. Now some aluminum refractory aluminum alloy cable and cable manufacturers claim to production by the relevant national standards for testing, but no difference in aluminum alloy aluminum cables and cable this, if the fire center (above) the melting point temperature is higher than the aluminum alloy and aluminum cable, no matter what kind of cable do heat insulation measures, the cable will be melting in a very short period of time, loss of conductive function. Therefore should not be used as refractory aluminum and aluminum alloy cable conductor, unfavorable also in densely populated urban distribution network, used in buildings, factories and mines.