Transformer primaries out of phase?

Wow. The build is actually beautiful to me. Neat wiring and attention to detail. It is the kind of thing could happen to anyone. I second the thought of using Nylon or other sturdy product. The responses were all spot on, and that really helps when you are trying to troubleshoot a basic flaw. I want to see more photos of this project. From what I already have seen, I would likely get some good ideas for a future build.
 
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It's always good to learn something new. Maybe this is common knowledge, but I learned that surrounding a toroid with a ground is a bad idea.
I thought the small adjacent toroids were creating some competing magnetic fields and causing the problem, but that was not the case. When I disconnected them from the terminal block the problem persisted. But as soon as I removed the terminal block and bracket going across the top, the problem went away.
Go figure.
A common mistake! At least you now know👍
 
The build is actually beautiful to me
Thank you. I actually like the fabrication as much as the electronics. The chassis is an old 70's Kenwood receiver that I'm retrofitting with a modern PS, amp, and preamp. Space is tight so I have to be careful with the layout. This is my 3rd build like this, I love that era.
I'll post more pics as it slowly progresses.
 
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It's always good to learn something new. Maybe this is common knowledge, but I learned that surrounding a toroid with a ground is a bad idea.
I thought the small adjacent toroids were creating some competing magnetic fields and causing the problem, but that was not the case. When I disconnected them from the terminal block the problem persisted. But as soon as I removed the terminal block and bracket going across the top, the problem went away.
Go figure.

Did you try to float the bracket so it wasn't connected to ground?

As is, it looks like it creates a current path to ground via inductive coupling, huh?
 
Yes, I am laughing too. If they came up with a direct answer or understanding of the concept that would be pretty scary too. "Yes sir, in aisle #14 we have strips of material that could be cut to size and have an electrical insulation property out to 14KV. Let me know if you need me to help you calculate."
 
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It's interesting in that the excess current seemed to be in the bolt and bracket, that's where I noticed the most heat. The transformer didn't seem to get warm, so hopefully I didn't damage it.
The reason it seemed to be in the bolt and bracket, is because it was. If you were to short your secondary windings, you'd expect to have all the current flowing through them too. The bracket with bolt going through it was creating exactly that, albeit the winding was made out of steel and it was just one turn.

The bolt and bracket were simply the smallest amount of surface area per cross section of material, so it would get hotter as the heat can't be dissipated as easily.
 
The primary was probably heating up too - but it would have taken a while for the heat to reach the surface. And if the shorted turn were very lossy compared to copper wire, the resistance at say a half volt induced in it might have limited primary current to something reasonable anyway. Half a volt (per turn, typical of a toroid around 200-400 VA) at 200 amps is only 100 VA. It’s when you get thousands of amps in a shorted turn that things get interesting. Might not even hurt the transformer, but cause things to melt.
 
I cut up a plastic case that I found and it worked perfect. The cover I got for the terminal block is the wrong size.
No more toaster.
Thanks for all the wisdom.
On to the next stage...P3A
 

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