1) At the end you show the primaries connected to the ground. Assuming that's just a drawing error, and moving on, I don't grasp how you can have any transfer of power with nothing connected to the H1B posts.
The HV primary has a ground shield on the outside of the cables. I can't answer how this works as I don't work on utility lines but I have seen installations with this setup. The utility may not have 3 primaries in some areas and this setup only requires 2 primaries for 3 phase power. I believe the H1B primary is left floating to allow unbalanced loads on single phase and maintain balance on 3 phase loads.
Something it's not right, maybe in the primary that it's not connected (H1B), only one side H1A ?...H1A to Ground? , Sorry bun no. & the secondary winding need to follow the rules of ...
It's a case grounded transformer. Primary side is setup here in a open wye configuration utilizing the case as ground/neutral. H1B is a feed through from H1A.
Sorry, very poor explanation of the mathematical relationships that determine the secondary voltages. In my EE schooling our instructor showed us how the Wye and Delta configurations were made diagrammatically, and the math involving in computing the phase currents and voltages. And why would one transformer only be for lighting, and another for power? In a commercial building service, yes, we use the 480/277 panel for lighting often, and then step down via transformer to a 208/120Y service for building power needs. But on the utility side as you describe here???????? Don't get it. Perhaps this video assumes that the student watching it already has worked in the utility field for years, and so may know what you're talking about. But as a building engineer and master electrician, myself, it makes no sense!
1) At the end you show the primaries connected to the ground. Assuming that's just a drawing error, and moving on, I don't grasp how you can have any transfer of power with nothing connected to the H1B posts.
The HV primary has a ground shield on the outside of the cables. I can't answer how this works as I don't work on utility lines but I have seen installations with this setup. The utility may not have 3 primaries in some areas and this setup only requires 2 primaries for 3 phase power. I believe the H1B primary is left floating to allow unbalanced loads on single phase and maintain balance on 3 phase loads.
Something it's not right, maybe in the primary that it's not connected (H1B), only one side H1A ?...H1A to Ground? , Sorry bun no.
& the secondary winding need to follow the rules of ...
It's a case grounded transformer. Primary side is setup here in a open wye configuration utilizing the case as ground/neutral. H1B is a feed through from H1A.
Sorry, very poor explanation of the mathematical relationships that determine the secondary voltages. In my EE schooling our instructor showed us how the Wye and Delta configurations were made diagrammatically, and the math involving in computing the phase currents and voltages. And why would one transformer only be for lighting, and another for power? In a commercial building service, yes, we use the 480/277 panel for lighting often, and then step down via transformer to a 208/120Y service for building power needs. But on the utility side as you describe here???????? Don't get it. Perhaps this video assumes that the student watching it already has worked in the utility field for years, and so may know what you're talking about. But as a building engineer and master electrician, myself, it makes no sense!