We are looking for a transition splice for 3/c PILC to 3-1/c polymeric(XLPE) primary underground cables. The 350 PILC CABLE has conductors of a compact sector shape. We are not sure on how to calculate the PILC insulation diameter for each of the copper conductor since they are not round. However, we do have the 120 compact sector conductor V-Gauge Depth for each of the conductors. The supplier has not been very helpful on how to go about this. Does anyone know how to calculate the insulation diameter for a PILC conductor by knowing the V-Gauge Depth of the conductor and the thickness of the insulation? Any assistance will be highly appreciated and thank you in advance.  

What voltage are we talking about?
These days connectors and joint kits are range taking based on conductor CSA rather than shape. If you think about a heatshrink tube, for example, its not going to matter whether the conductor is sectoral or circular providing the tube is big enough to slide over the connector and can shrink down enough to be a tight fit on the core.
Regards
Marmite  

I believe Burndy sells "rounding dies" to allow use of a circular splice with segmented conductors.