Comment on What is negative voltage?
akunohana@piefed.blahaj.zone 4 days agoI will definitely keep in mind, that what we use are the differences in voltages (which even makes sense if one were to use the water pipes metaphor).
So, the only reason we have absolute values in our outlets is for compatibility (to make manufacturers lives easier?) and to have some “wiggle room”?
We don’t use absolute values in out outlets because there are no absolute values for voltage.
The line in your outlet oscillates between positive and negative (sqrt(2)*V) relative to the neutral, where V is the nominal voltage of your place. And because this is symmetric, you can also say that the neutral oscillates on the same range relative to the line.
Tolookah@discuss.tchncs.de 4 days ago
Once you add in outlets, there’s a reference.
Assuming you’re in a US home similar to mine here: Ac power typically comes into an outlet as two to three conductors. One is live, one is neutral, the other is ground.
The neutral is your 0v. In the house, that’s often tied to a water line at your breaker, or a rod inserted into the earth, a ground rod. The ground is also tied to neutral in the breaker, and is there for protection. (GFCI outlets test for current on the protection line and if there is any, shuts off the outlet because that’s a fault condition).
Tldr: 0v/ground in your home is referenced to actual ground, the earth, typically in the breaker box.