In article , The Natural Philosopher
scribeth thus
On 28/07/14 16:06, Tim Watts wrote:
On 28/07/14 14:48, wrote:
Nightjar wrote:
It's losses in the dielectric, so it applies to underground cables too.
Like the man says, although the problem is significantly greater under
water. 30km is about the limit for AC transmission under water, (...)

Sorry, I still don't understand this. We're talking cables not
capacitors.
How does a 16mm2 PVC insulated cable have a higher resistance if it's
immersed in water than if it's in a vacuum?


It doesn't. It has a lower Line-Earth reactance (capacitative) - at
least that is what's being claimed.

However, the cables are all armoured so it does not really matter if
they are in a dry tunnel or under the sea.

Mmm. Not sure that is so, but cant put a finger on why I feel its
different..


The big difference is a cable vs overhead lines.


Yes.



Yep water -v- air cooled...

--
Tony Sayer