Plastic-insulated high-current LV cable - has massive aluminium phase lines and gaps trapping moisture when damaged

摘要

The high current LV cable has four massive aluminium conductors each with a quadrant shaped cross section. An insulating cross is located at the centre of the cable and separates the four conductors from one another along their entire lengths. The gaps formed by this cross between quadrants are left empty, or packed with paper. The whole is then doubly insulated with two plastic sleeves. If the cable is damaged and moisture enters, the gaps left by the cross ensure that at least one phase line is shorted to the neutral line and therefore allows the damage to be detected and the cable section replaced. If there were no gaps to take up the moisture, the neutral line could corrode right through without any means of detecting the damage.