Alias-_-Me t1_j9taf7m wrote on February 24, 2023 at 12:12 PM

Reply to comment by DeexEnigma in [Image] by lawwal93

What's the difference?

AnyAmphibianWillDo t1_j9tjoug wrote on February 24, 2023 at 1:37 PM

I have almost no electrical knowledge but I think "earth" or "earth ground" would imply that wire is connected literally to the earth at some point, e.g. in home wiring there can be a copper rod driven deep into the earth that all the "ground" wires are connected to, making those earth grounds?

I think the word "ground" by itself is often just used to refer to the common (shared) part of a circuit, eg. on an arduino there's a ground (GND) pin that's obviously not connected to the earth, but used as a shared source of "lower electric potential" for all parts of the circuit to use to create the difference in potential required to have "voltage"

Why OP says there is an earth wire in the picture and not just a ground, idk. Those 3 wires could easily be used for something that has no earth ground. Maybe the color scheme of those 3 wires is a standard one and the green usually is earth ground? No idea. Maybe there's just different terminology standards than I'm aware of and in the shitty hobbyist world I live in we all use the words wrong ¯\_(ツ)_/¯

Odissus t1_j9tnn4x wrote on February 24, 2023 at 2:08 PM

That’s actually quite accurate! To answer your concerns, for (single phase) AC like in many outlets, ground (the reference voltage) is most convenient to be the same as earth (0V). For this reason calling earth “ground” is fine, as more often than not it’s both earth and ground.

Just to add, any voltage you use often in a circuit as a reference (say for comparators for example) is called a reference ground. So if you split 0 to 5 V in half, and keep using 2.5 V for various comparison purposes, the 2.5 V could be called a reference ground.

DeexEnigma t1_j9vdw06 wrote on February 24, 2023 at 8:53 PM

Depending on context. In an AC mains power application the earth wire directly ties to a stake that's in the earth outside. This provides a safe return path for faulty circuit conditions.

Ground is a broad term in DC applications where it is the main negative' plane or hookup. However you can have ground in an AC application where it usually is the neutral return.

Generally green in mains power (Australia/NZ and I believe EU) is always the earth.