[persolb]

Is the air gap actually an issue in this case? If I'm understanding correctly, the suggestion is to put up additional cable instead of thicker cable. The two ends of the cable are both still connected to the same electrical phase, so there should be no arcing between them.

[doctorwho42]

Let's assume just high voltage cables (110kV [110,000 volts]}, if you put two cables connected to the same source and terminus, over 100 miles of cable you will easily see resistance variation between the two... Not including any environmental changes. High voltage starts to become a bit of magic when it comes to shielding it. You could have an inch of rubber insulation around that cable, and still have a static charge build up on the outside. If another cable or ground path is within a certain distance, you are going to cause arcs depending on the RH% in the air. One arc will cause degradation to the point it arcs to, and if it's the other cable - that will improve it's ability to arc again.

Long story short, when you start to enter the kV range, your traditional rules of thumb go out the window. I have first hand experience with trying to keep a particle accelerator from arcing, and that was a nightmare ... I can't imagine mixing in high current as well.

[7952]

HV powerlines often use bundles soacedd at around 40cm that are regularly linked with conducting fittings.