Amazing stuff

did it? cut wire at what current rating?

The professor had to give us a hint with the neutral wire analogy

When I figured it out I slammed the desk with my eureka moment

ah, guess you are only dealing with WYE connections

Triphase

220

220v triphase thing

I DEMAND A 2ND REFERDUM

Fault in the control circuit

220 Delta vs 220 Wye

It was a motor starter simulator

Both are triple phase

https://www.youtube.com/watch?v=dI-JW2UIAG0

one uses 3 wires not 4

It switched from triangle to star connection

4

It had an earth and 3 phases

ah yeah, that is what so me call it; triangle or star

did this turn into an EE course?

yes. Please calculate the ground fault current if a 1.4KV XFMR shorts the seconday windings with a sufficently large conductor as to exceed the per unit XFMR rating.

lol

I fucking punched the desk when I figured out the exact wire that was supposedly cut

It was so satisfying

lol yeah, i've had that at home actually

One yr during a storm, I lost the neutral line running from the pole to the house.

Sadly, it wsn't the ONLY wire running from the house to the pole as my cable modem conductor was also hung that way

The reason that wire being cut caused all the issues was that it allowed the lamp's phase to act as a latch for the relay that kept the lamp turned on, the wire layout caused the faulty latch to bypass the off button, and pressing the on button connected the same phase on both pins of the lamp, turning it off. @ManAnimal

With no neutral, return current had to go SOMEWHERE

melted the HELL out of that tiny coax cable in about 1/2 a second

Do you know what a 'synchroscope' is Timeward? It works on a similar principle

In power distribution, you have a large load or 'grid' and you want to provide more capacity to a live circuit without turning everything off

but if your on-coming 3-phase generator runs at a freq even SLIGHTLY out of phase with the online system, you'll see a LARGE voltage across the switch/breaker you are closing. As there is usually hundreds or even thousands of amps available, closing 180 deg out of phase can turn a 1 ton circuit breaker into a projectile

Text

@PureEvilPie Little mistake in alignment makes lever in wall go boom

A 'sychro-scope' has an analog meter and a pair of 'sync lamps' connected across the online and oncoming behind an isolation xfrm set. When the voltage is 'in sync' the lamps go off

when the sources go out of phase, the lamps come on get brightest at 180, then dim again

lights are out? close breaker

Maybe thats why the two ohases we measured yesterday were at 380V

yup