Crush and shear protection are limited. Crystallization from vibration and thermal cycling can lead to moisture leaks. Relatively low emergency temperature capability limits fault current capacity. Higher weight and pulling forces increase chances of cable damage. Welded and corrugated copper is most often the material of choice, though welded and corrugated aluminum, and composite laminates, offer lower-cost alternatives in specific applications.
Cables going into ducts built for PILC technology have to be small, and they have to be tough.
The good news is that test results show we've got an extruded-dielectric design that's a very viable PILC replacement. Further testing at Southwire's Cofer Technology Center has subjected these cables to dry cyclic aging and accelerated aging in water. Smaller is better. So is tougher. The PILC replacement design challenge starts with cable diameter.