# Three-Phase Delta Network: Not all Voltage Sources are 120V?

1. Feb 22, 2016

### yosimba2000

Using the Delta Netowrk from this image: http://www.belden.com/images/B23_WyevsDelta.jpg

Between Y-X, there should be 120V.
Between Y-Z, there should be 120V.
Between X-Z, there should be 120V.

But wait!

If we assign values to make the above statements true...

Call X = 0V, and Y = 120V, so from Y-X is 120V.
If Y-Z should be 120V, and Y is already 120V, then Z should be 240V. This is so from Y-Z is 120V.
If X-Z should be 120V, and Z is 240V, then X should be 360V.

But that can't be, since we already said X is 0V to make Y-X = 120V. From what I know, if X is held to be 0V and Z is 240V, then from Z-X is 240V!
If X is made to be 360V, then Y-Z is no longer 120V!

What am I doing wrong?

2. Feb 22, 2016

### cnh1995

120V will be the rms value of voltage and not the instantaneous value. Instantaneous values will be different at each instant.

3. Feb 23, 2016

### jim hardy

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook