How 3 Phase Transformers Work – why we need them

How do 3 phase transformers work, why are three phase transformers used, how do they produce 480V, 277V, 240V, 208V and 120V. What is wye delta, open delta and high leg delta. What is a pad mounted and pole mounted transformer and how is three phase electricity generated?
Edit 8:36. Nameplate shows Delta-Wye not Wye-Wye as text shows

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[EngineeringMindset]

*This free video took WEEKS to make!* If you’d like to support Paul’s efforts, links below:

[davidsawyer]

The algorithm suggested this video?
I am a retired electrician. 35 years commercial, industrial and Institutional.
This lesson brought me back all those years to the beginning.
I had a great teacher. He used similar illustrations except it was using an overhead projector.
It's very rare that I watch anything to do with my former life.
This was some good fun.
You did a great job.
Thanks.

[carlluis]

I am an Electrical Engineer graduated in 2020 I find your videos very helpful for my MEP Construction Job and understanding the National Electrical Code and Electrical theory.

[JunWu]

I’m showing all my substation interns this video to help them understand the madness behind electricity. ⚡️ As a PE working in substation engineering, I wish I had videos like this when I started 10 years ago. I truly appreciate your gift to teach. 🤝

[matthewmiller]

Just wanted to say I really appreciated how you re-orient some of the diagrams that position the schematic how it would be sitting in a physical transformer...as someone who is just curious "how stuff works" this is something I've never been able to wrap my head around you could have separate transformers doing 3 phase power even though I've seen the "triangle and Y" positioned diagrams countless times I just couldn't wrap my head around how it was possible until I saw your diagrams MOVE in the video and something finally clicked how the "real world position" would be vs the "diagrams" you see all the time! That was great!

[wyattb]

I’m a mechanical engineer and got an electrical engineering job for my city because they couldn’t find qualified applicants and I needed to work. This helps a ton and helps me learn!

[ivankuseta]

Half semester of basic electrical theory in 24min.
Where were you when I was graduating? 😂
Amazing.

[BornAnt]

As a college grad in Electrical Engineering you guys won’t find anything better than this video. This is as good as it gets.

[VTdarkangel]

Some interesting things about 3phase transformer connections.

Delta - Y is usually preferred. Thats because 3rd harmonics don't get transmitted back into the incoming line.

A zig-zag transformer can be used to create a central ground for delta connections, but that is only used for special industrial settings, at least to the best of my knowledge.

In the US, Delta high leg and open delta are becoming obsolete. They were an out growth of the split phase systems used in residential power configurations. They are usually not installed in new service systems anymore. The vast majority of operating ones are legacy connections.

[ChunskieFartFilms]

Working in electrical distribution. Realized a lot of people don’t understand how this stuff works (electrical distributors), and wasn’t satisfied with the explanations I was getting for how electricity worked. Started watching your videos and the stronger understanding you have given me got me promoted to industrial electrical sales. Best electrical channel on YouTube hands down.

[Hexlattice]

Ok. Ok. I understand that this might be more information than most people even care to know about how electricity (like the stuff that powers your home and, well, life) works, but I found this single video to be just about the best crash course on the subject that I've ever seen. He's managed to condense an entire college course of material into one video. Blew my mind at how well he did this.

Also, don't let the British accent throw you. He's explaining the USA power grid.

[CrownRider]

As a retired Dutch engineer, working with single fase and three fase only, without any half tap at 120 Vac, this video finally explains how it works in the US. Thank you very much.

[Sparky-wwre]

In 2005 when my mother remarried and moved to my stepfather's farm, we had an open delta 3 phsse, because we had a grain dryer, conveyer and large auger with 3 phase motors, with the majority of our loads being 120/240 single phase, transformers on the roadway, pole with meter and site disconnect in the middle of barnyard, single phase ran to house, 3 phase to barn, where there was a 3 phase panel dedicated for the motors, also feeding a single phase panel beside it for the other loads. Otherwise roughly 1/3 of the panel slots would be wasted because the B phase (high leg) is unsuitable for single phase loads, which is a major disadvantage of a 4 wire delta service and thus the 208Y/120 & 480Y/277 (or 600Y/347, if you happen to be in Canada or a few areas in the US) is a much more common and useful configuration.

Open delta is still fairly common on some farms and small commercial buildings where the customer has mostly single phase loads, while also requiring limited amounts of 3 phase power, since it's cheaper to set up than a wye bank.

[djo_man]

Funny enough, the switch from solid block cores to plate stack cores wasn't because of eddy current losses, although it was a nice bonus. It's mainly because it's cheaper to stamp out a bunch of steel plates and stack them, rather than milling out the shape of the block.

[Frontslider]

I was an industrial electrician 35 years ago. Great video.

[khoanguyen-ejmd]

this channel is 100 times better than my

[stevelaurito]

Ive been involved in the electrical trade off and on for 35 years. This is the BEST explanation ive seen. Very well done.

[jassihra]

That was a GOD level explanation. Not even professor But, GOD level I bow down to you

[HonoredMule]

This might be a bit dense for a total newbie, but I'm finding it a wonderfully efficient, clear, and comprehensive refresher that really brings together the substance of multiple other longer sub-topic videos.

[Grimx]

I really needed this video 6 years ago in electrical school. I've never seen transformers visualized so well!