Harvard wrote:
Re: "Look at the insulators"
Where is the 3rd phase?
That would be a lower voltage "local" single phase transmission line, one hot and one neutral. Maybe 60 KV? The hot and neutral cancel out the EMF. Three phase 500 KV transmission lines (usually 3-conductor delta configuration, not wye) are more efficient and transit more power using comparatively smaller size aluminum conductors and less aluminum per foot. The 3 phases (180 degrees apart) also cancel out the EMF. Below is what a 500 KV transmission line looks like and are much taller.
Local residential/rural high voltage lines on streets (in Canada at least) are 12 or 25 KV and the high voltage primary and low voltage secondary (120/240) share a common neutral which is why you see only one insulator on the poles like in diagram below.
In the last diagram, which wire is a neutral and what is the voltage?
