Please explain the difference between single phase and three phase. I’ve tried to figure it out but I can’t get a grasp of it.
In: Physics
I’m assuming you are referring to AC power transmission, so I’ll explain that.
For single phase power, there is a ground wire, and a live wire that alternates from positive to negative in a sine wave, using the ground wire as its zero point. It’s convenient for short runs and lower voltages, as Single phase is easy to get into DC power.
Three phase power’s quite a bit more complicated, but enables using thinner wires (think three smaller wires instead of two large ones). It has three wires. Each one has a similar sine wave to the live wire of the single phase, except they’re all out of phase. That means that when Wire 1 is at it’s zero point, wire 2’s a third of the way through it’s wave, and wire 3’s two thirds through its cycle.
For a graphical explanation that may or may not help, imagine a normal X-Y graph (I know, this isn’t 5 year old math.), with a circle centered at (0,0). There are three spokes 120 degrees apart, and where those spokes meet the circle, there are points. The Y value of points 1, 2, and 3 represent the voltage of wires 1, 2, and 3. So as time goes on, the circle rotates, each point following a third of a rotation behind the previous one.
Latest Answers