the maths behind one phase of 415V 3 phase power being 240V and not whatever 415/3 is
In: 16
European standard is 230V AC, 50 Hz. I’ll use those numbers.
The power in the outlet is 230V AC, in reality it varies between 325V and 0V and -325V and back to 0V again 50 times a second. The number 230V is just an average (root mean square) over time.
If you take two of these outlet and measure the voltage between them you’ll get 0V all the time. They are both at 325V at the same time, and both at -325V at the same time and the differences between them is always 0V.
Here’s the trick. What if they *weren’t* at their top voltage at the same time? Then you’d measure a difference between them, right?
Three phase 400V is three voltages that varies between 565V, 0V, -565V and back to 0V again. They don’t have their peak at the same time, but is delay a third period from each other. The difference can be calculated with trigonometry, and comes out to 400V divided by square root of 3.
Latest Answers