I have run into a situation where a utility had decided some time ago, for whatever reason, to replace there main feeder cables with shielded EPR when they need to be upgraded.  Their old standard was concentric neutral cable.  For example, a feeder getaway would be upgraded from 750 Al 15kv XLPE CN to 1000 Al 15kv EPR w/8 mil cu shield.

My problem with this is that they are not pulling in a separate neutral with the shielded cables.  My contention is that shielded cable is not meant to be a direct replacement for concentric neutral and that they are effectively eliminating the system neutral.  The shields main intention is to evenly distribute the electric field about the conductor, a concentric neutral on the other hand has a dual purpose as being a neutral and to distribute the field.

The shield is 8 mil x 5.25" /phase.  My calculations says that this equates to about a #7 cu neutral.  In contrast to a 1000 mcm Al CN cable which comes with 20-#10 cu /phase for a neutral which would equate to about 622 mcm of copper.

I also realize the implications of circulating current in the shield and the safety hazards that can be created.

Has anyone else run across this question/problem?  I can find nothing in writing to state that the shield is not a neutral replacement.  My assumption is that it is not in writing because everyone knows it to be.

Your feedback would be appreciated.  Thanks.