On Tuesday, September 10, 2019 at 2:01:56 PM UTC-4, devnull wrote:
On 9/10/19 1:05 PM, trader_4 wrote:
You might want to improve your reading comprehension skills. Neither I
nor the professor said that we would call it two phase. Only that what
is actual there are two voltage sources, two phases that are 180 deg out
of phase with each other.

You only *appear* to have two phases when you hook one pair of your oscilloscope leads up backwards.

That's totally wrong. Take the scope ground and connect it to the logical
system reference point, the neutral. Take one probe and connect it to
L1 and take another probe and connect it to L2. Nothing "backwards"
there. And you will see two 120V sine wave voltage sources, 180 deg
out of phase with each other. It's how you get 240V between them.