So what provides the best positive ground?earth provides the best negative ground.
I would think whatever the clouds do in a thunderstorm. Maybe someone will put that in a battery.So what provides the best positive ground?
At least others might read the post and learn something from the responses.Why do we bother?
It seems to be that way in the US, for what I've been told, but here neutral is different from ground. Although neutral is referenced at 0V, it comes from a three-phase transformer. Earth is local, and it is not connected to ground.AC panel : for each breaker, neutral goes to a large bus bar, which is earth grounded [ at least so far as I have seen ]
It is possible to know the absolute charge of an object. Consider an electron +1, a hydrogen atom 0 = 2 -2 etc. Of course these are a bit unusual items. In any case the meaning of potential is an abstraction that comes from the nature of the electric field which is a bit less abstract. Since the field is conservative it can be derived from a scalar function of position. Del dot this function is then the electric field. The function is not unique, but all such functions differ only by a constant so potential differences are unique. Where 0 is is entirely up to you, but once chosen can not be moved around without adjustment.Since the theory here is a bit fuzzy, I'll explain. As you know, all objects have electrons, and therefore, charge. But it is impossible to know the absolute charge of an object, snip......
I suspect that what you may mean by your question is "why" is there a ground or reference point in a circuit. Well consider this, when we say a mountain is 10,000 feet high, what do we mean? 10,000 feet higher than what? We don't mean 10,000 feet above its base because its base may be higher or lower than another mountain's base so it would then be very difficult to get a relative comparison of mountain heights.Why we consider ground or reference point in electronic circuit.
But if the middle wire is the reference, then its voltage won't change. It will appear that the voltage on the other two wires is changing relative to our 0v reference............what happens if you choose the middle wire and its 'voltage' switches between -25 and -25 once every 10 seconds.Meanwhile The voltage on the other two wires interchange 10 times every second.
What is the ground voltage now?
You need to take time into account.
If you really think this perhaps you would like to explain why we ground protective earths to a well buried heavy duty metal stake rather than a one inch nail, dangled out of the window.But if the middle wire is the reference, then its voltage won't change. It will appear that the voltage on the other two wires is changing relative to our 0v reference.
If you read what I wrote carefully, you will see that I covered the point you have tried to make. If you need me to explain it in words of one syllable, I am of course happy to do so.If you really think this perhaps you would like to explain why we ground protective earths to a well buried heavy duty metal stake rather than a one inch nail, dangled out of the window.
By your reasoning it would make no difference to the person holding the exposed metal part of apparatus when a line to ground short occurs.
Humour me. The stage is yours.If you need me to explain it in words of one syllable, I am of course happy to do so.
Maybe you could explain the concerns of 'step voltage' surrounding substations.If you really think this perhaps you would like to explain why we ground protective earths to a well buried heavy duty metal stake rather than a one inch nail, dangled out of the window.
time is irrelevant, a man made unit of measurement! if you really want an equivical answer- leave time out of the equation. Maybe change 60 seconds to 75 seconds per min. Total man made---total B.S.You need to take time into account.
by Jake Hertz
by Duane Benson