Medium Voltage Inductive Heating

[nickoliver]

I thread in another forum has sparked my curiosity. The subject being the practice of utilities transitioning from overhead to underground (66KV) with the insulated (UG)cables entering a steel pole through individual holes. Since there is no mutual canceling of phases with this arrangement is there ever a problem with inductive heating? Does the shield around the cable have any effect in minimizing this?

 

[NorthSlope]

Shielding on the cables is for voltage field control - NOT magnetic field control. It is entirely possible to use non-magnetic steels for a structural member and route all three phases, individually, through the same plate. Large transformers do this all the time.