structures are likely initiated at the surface of the
conductor screen of insulated XLPE cables with stranded
aluminum conductors due to water ingress and corrosion.
In time such structures initiate severe vented water
treeing which significantly reduce the lifetime to the cable.
The main purpose of this paper is to show that SIED
structures are porous structures which swell and become
visible after wetting in hot water, by using non-contact
surface metrology characterization.
It is found that after wetting SIED structures were imaged
as elevations of water saturated porous structures. The
swelling was less than 10 μm and could be permanent
dependent on ageing conditions