These include: aluminium EC rods, manufactured with 99.7 per cent minimum purity and used in cables and overhead conductors; all aluminium conductor, concentric lay stranded conductor
and used as bare overhead conductor for distribution lines; aluminium conductor steel reinforced, concentric lay stranded conductor
with galvanised steel central core and used in medium, high and extra-high voltage transmission lines; and aluminium conductors aluminium-clad steel reinforced, a concetric-lay stranded conductor
with aluminium-clad steel core and used in medium, high and extra-high voltage transmission lines.
At first glance, an epoxy-sealed cable passthrough would appear to have several significant leak paths: the stranded conductor
, insulation (especially Teflon), any sheilding, and the epoxy bond between the cable and any metal housing.