Triplen Harmonics
Three balanced phases, 100 amps each. So why is the neutral carrying 60? The 3rd harmonic runs three times as fast, lands on the same spot on all three phases, and adds up instead of cancelling.
Watch on YouTube ↗Resources · Free Stuff
Free Resources.
How's and Why's, explained the way you'd hear it on the job. Everything here is free. New videos land on the channel first, usually weekly if I have time.
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Why You Float the H2's on a Wye-Delta Bank
Ground that primary neutral and four things start: the bank turns into a grounding bank, it circulates current, third harmonics get a loop to run laps in, and one open fuse leaves it limping as an open bank.
Watch on YouTube ↗The 120V and Wild Leg Nobody Pulls Off a Corner Ground
You can still get 120 and the wild leg off a corner-grounded delta. You just don't typically see it done. Will you ever need to? Not likely, but it's worth knowing every option you have.
Watch on YouTube ↗The System Neutral, Part 2: Grounding
I almost burned a house down once. Not with primary, not with secondary. With a neutral. Three trouble calls and four different transformer grounds: broke, burnt up, or otherwise missing.
Watch on YouTube ↗The Square Root of Three
57.7, 86.6, 208, 12470: every one is 1.732 wearing a different hat. The Pythagoras behind root three, and why it shows up everywhere in three-phase.
Watch on YouTube ↗The System Neutral: Neutral vs Ground
Why the neutral IS the ground up the pole, why a healthy pole ground reads amps, and where the two finally split at the customer.
Watch on YouTube ↗The Open Bank: Two Pots, Full Three-Phase
Both ways to build one, how the erased side of the delta still reads 240, and why the wild leg lands where it does.
Watch on YouTube ↗The Corner-Grounded Delta
One phase reads 0 volts to ground and nothing is wrong with that bank. The readings on 240 and 480, and how to tell it from a fault.
Watch on YouTube ↗Why the Wild Leg Reads 208V
You know it reads 208. This is the why: the geometry of a closed delta secondary and the math behind that number.
Watch on YouTube ↗Read & Print
Free Lesson
What Is a Transformer?
Lesson 1 of XFMR Training, free and no signup: the primary and secondary sides, the two coils, turns ratio, tank grounds, and polarity. The exact lesson from inside the app.
Read Lesson 1 →3D-Printable
The Hand-Tie Speed-Roller
Partnership with Poletop. Free STL, print it and run it.
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⚠ Super glue the handle in place.
↓ speedRoller.stl · 3.3 MB