LINEMANAPPS
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Watch & Read

Video Explainers

Every explainer in one place. Each one is a short video plus the full written write-up: the same theory, on the page, so you can read it on the truck without the sound on. All free, no signup, built by a journeyman lineman.

An amp clamp reading 3.2 amps on a pole ground wire with the neutral bonded above it. Video Explainer · New The System Neutral: Neutral vs Ground Why the neutral IS the ground up the pole, why a healthy pole ground reads amps, why the neutral only carries the unbalance, the 1932 study behind bonding everything together, and why an intact neutral is safe to touch but a cut one can kill you. Watch & read → The Open Bank. Two transformers in the XFMR Lab sandbox producing a full three-phase secondary. Video Explainer The Open Bank: Two Pots, Full Three-Phase Two pots on the pole and full three-phase coming off them. Both ways to build one, how the erased side of the delta still reads 240, why the wild leg is still there, and why nobody makes three-phase out of single-phase. Watch & read → The Corner Ground. A delta secondary triangle with one corner bonded to ground reading 000 volts. Video Explainer The Corner-Grounded Delta One phase reads 0 volts to ground and every other reading is the pot's full secondary rating. Nothing is wrong with that bank. Here's the why, the readings on both the 240 and 480 class, and why 000 never means de-energized. Watch & read → The Wild Leg: How and Why. A closed delta secondary drawn as a triangle. Video Explainer Why the Wild Leg Reads 208V You know it reads 208. This is the why: the geometry of a closed delta secondary, how the ground reference sets the wild leg's corner, and the math behind 1.73 × 120 = 208. Watch & read →

New videos land on the YouTube channel first, then get a written write-up here. Looking for the free lesson and the printable field tools instead? They're back on the resources page.