Re: Re: Safety Ground
Hi Steve,
Regulation= regulation. (NEN-1010)
I believe neutral is connected to earth (soil) at the powerplant
Steve,
Here and on the Audio Asylum I became under the impression you enter the discussion just for the sake of the argument....
For me this forum is to learn and to exchange ideas and hints.
Here and on AA I repaired two CD-players by "remotecontrol".
I got nice feedback on my clock. From Fred's links to all kinds of interesting papers I learnt tremendously. Also Jocko's and Jonathan Carrs and others approach can be very interesting....
All the best,
- -
Steve Eddy said:
Hi Steve,
Regulation= regulation. (NEN-1010)
I believe neutral is connected to earth (soil) at the powerplant
Steve,
Here and on the Audio Asylum I became under the impression you enter the discussion just for the sake of the argument....
For me this forum is to learn and to exchange ideas and hints.
Here and on AA I repaired two CD-players by "remotecontrol".
I got nice feedback on my clock. From Fred's links to all kinds of interesting papers I learnt tremendously. Also Jocko's and Jonathan Carrs and others approach can be very interesting....
All the best,
- - 
Re: Re: Re: Re: Re: Re: Re: Re: Re: Re: Re: Re: Re: Waterpipe Grounding
We let them build their houses on the beach five feet from the Atlantic Ocean and on hillsides because it's a good source of entertainment on the evening news for those of us who aren't that stupid.
It's distributed at 220 volts. The 110 is picked off either side of the center tap. And of course many homes have at least one 220 outlet for things such as electric clothes dryers.
It wouldn't matter?
What would happen if one were to reverse the plug on one component relative to another? One component's chassis would be tied to neutral and the other to hot. Worse, what if one outlet were wired to one "phase" of the line and the other to the other? Now instead of 110 volts between the chassis, you've got 220.
That's the main reason why the safety ground is a separate conductor going back to the neutral line at the service panel.
What GND do you mean? The safey ground? Ideally the safety ground carries no current except under fault conditions. Though in real life it carries a wee bit of leakage current due to capacitive coupling with the hot lead.
How many amps will depend on the voltage. The choice was made so in the event that the hot lead contacts the equipment chassis, the safety ground provides a low impedance path back to the source, which ideally would result in 0 volts on the equipment chassis.
Excuse me? GFCIs (Ground Fault Circuit Interruptors) work just fine on US power systems. They sense the differential current flowing through the hot and neutral leads. If the current flowing through the hot lead doesn't match the current flowing through the neutral lead, it breaks the circuit.
se
grataku said:
We let them build their houses on the beach five feet from the Atlantic Ocean and on hillsides because it's a good source of entertainment on the evening news for those of us who aren't that stupid.
It's distributed at 220 volts. The 110 is picked off either side of the center tap. And of course many homes have at least one 220 outlet for things such as electric clothes dryers.
It wouldn't matter?
What would happen if one were to reverse the plug on one component relative to another? One component's chassis would be tied to neutral and the other to hot. Worse, what if one outlet were wired to one "phase" of the line and the other to the other? Now instead of 110 volts between the chassis, you've got 220.
That's the main reason why the safety ground is a separate conductor going back to the neutral line at the service panel.
What GND do you mean? The safey ground? Ideally the safety ground carries no current except under fault conditions. Though in real life it carries a wee bit of leakage current due to capacitive coupling with the hot lead.
How many amps will depend on the voltage. The choice was made so in the event that the hot lead contacts the equipment chassis, the safety ground provides a low impedance path back to the source, which ideally would result in 0 volts on the equipment chassis.
Excuse me? GFCIs (Ground Fault Circuit Interruptors) work just fine on US power systems. They sense the differential current flowing through the hot and neutral leads. If the current flowing through the hot lead doesn't match the current flowing through the neutral lead, it breaks the circuit.
se
Re: Re: Re: Safety Ground
But the impedance path through the earth between a rod stuck in the ground at your house and one stuck into the ground at the power plant is going to be immense.
I'm sorry, but sticking the safety ground into the earth and not tying it back to neutral at the service panel through the lowest impedance path practical doesn't make any sense from any sort of safety standpoint.
Not at all.
If I see something which seems incorrect or doesn't make sense based on my understanding, I question it. The purpose being not simply to argue, but to get at the truth of the matter.
Contrary to moronic claims made by the likes of Fred that I think I know it all, I don't. And when I question something, I don't go into it with any notion that it's impossible that I could be wrong. I may well be wrong. And if I am wrong, I want to know about it.
Why is questioning and argument looked upon as such a bad thing by some? It's how we get at the truth and filter out that which is erroneous. If not for questioning and argument, we'd all still be afraid of falling off the edge of the earth.
So no, I don't enter discussions simply for the sake of argument. Just to get at the truth, whether the truth be that my understanding is correct OR that my understanding is incorrect.
Tell me, what do you do when you see something which doesn't make sense based on your understanding?
Great. I'm here to learn as well. But if one just unquestioningly accepts everything stated as fact without ever thinking or questioning, what real learning is taking place?
se
Elso Kwak said:
But the impedance path through the earth between a rod stuck in the ground at your house and one stuck into the ground at the power plant is going to be immense.
I'm sorry, but sticking the safety ground into the earth and not tying it back to neutral at the service panel through the lowest impedance path practical doesn't make any sense from any sort of safety standpoint.
Not at all.
If I see something which seems incorrect or doesn't make sense based on my understanding, I question it. The purpose being not simply to argue, but to get at the truth of the matter.
Contrary to moronic claims made by the likes of Fred that I think I know it all, I don't. And when I question something, I don't go into it with any notion that it's impossible that I could be wrong. I may well be wrong. And if I am wrong, I want to know about it.
Why is questioning and argument looked upon as such a bad thing by some? It's how we get at the truth and filter out that which is erroneous. If not for questioning and argument, we'd all still be afraid of falling off the edge of the earth.
So no, I don't enter discussions simply for the sake of argument. Just to get at the truth, whether the truth be that my understanding is correct OR that my understanding is incorrect.
Tell me, what do you do when you see something which doesn't make sense based on your understanding?
Great. I'm here to learn as well. But if one just unquestioningly accepts everything stated as fact without ever thinking or questioning, what real learning is taking place?
se
jh6you said:
The Earth's crust isn't a very good electrical conductor. If it were, we could distribute power over just one line and use the earth as a return and SY wouldn't have had to kill his mother's lawn.
Even over seemingly short distances. Which is why it's not a good idea to tie a safety ground to a cold water pipe. The impedance of the ground between the cold water pipe and the ground rod at the service panel (which is tied to neutral) is high enough that an equipment chassis could still present lethal volages in the event of a failure.
se
Steve Eddy said:
Hehehehe. True. Though he did qualify his statement with readily accessible. Unless you're privy to some technology none of us are aware of, I'd say the earth is just a wee bit more accessible to us than Jupiter and the Sun.
se
I read his AND statement as an AND statement. Nonetheless, with fabulous technologies like astral projection, sticking a copper rod into Jupiter should be no real trick. The cost of connecting to it with audiophile-approved cable might be a bit steep. OTOH, we can open up endless debates about whether using Jupiter or Neptune as the grounding spot gives better sound. My vote is for Uranus, where I have advised more than one audiophile to stick a ground rod.
jh6you said:
I think you're confusing charge with current.
And again, the earth's crust is not very conductive. Depending on the material and conditions conductivity of the earth's crust can range from 1 to 10<sup>-4</sup> mhos per meter. Contrast that with copper at about 10<sup>7</sup> mhos per meter.
So even at its best, the conductivity of the earth's cust is worse than copper by seven orders of magnitude.
se
hmmm. yes. but i think the eart is also some orders thicker between my house and the next earth stick at power transformer.
C = A•s
My FI trips when current goes from phase back to power plant by earth and not by null. If earth i a really good insulator there will not go much current back this way and it would not trip. I tested ..... it trips. So eart could not be a bad resistor...
Also the earth resistor is not as long as all the distance from here to power plant, there are earth sticks at all power plants and transformers around. And this earth resistor is something like infinite thickness compared to everything else.
This may be different in your country, i don´t know. Earth conductance i think is mainly caused by water and ions. Over here it rains often and soil is wet. If there is no water (or no ions) in the soil, resistance may go more toward high.
C = A•s
My FI trips when current goes from phase back to power plant by earth and not by null. If earth i a really good insulator there will not go much current back this way and it would not trip. I tested ..... it trips. So eart could not be a bad resistor...
Also the earth resistor is not as long as all the distance from here to power plant, there are earth sticks at all power plants and transformers around. And this earth resistor is something like infinite thickness compared to everything else.
This may be different in your country, i don´t know. Earth conductance i think is mainly caused by water and ions. Over here it rains often and soil is wet. If there is no water (or no ions) in the soil, resistance may go more toward high.
The thickness of the Earth past the depth of the electrode is nearly irrelevant.
I propose you try a simple, 20 minute experiment: Since we're talking about intensive and linear properties (conductivity), you can construct a nice little analog test: drive two 30 cm copper stakes into the ground about 15 meters apart. You're in the moistest, most conductive part of the soil, so this experiment will err on the conductive side. Now, use an ohmmeter and some thick cable and measure the resistance between those rods (keeping in mind the DCR of the cable, har, har). You'll find out how poor a conductor the Earth is.
http://www.amprobe.de/produkte/vde/GeoTest.htm
My DMM wouldn´t work - to do this like DIN tells me i need AC and Vmess between 4V and 24V
My DMM wouldn´t work - to do this like DIN tells me i need AC and Vmess between 4V and 24V
till said:
Sure, the earth's thicker but what's the area of your earth stick?
If your earth stick is 10mm in diameter and 1 meter into the ground, that's what, about 0.08 square meters?
I never said it was a really good insulator. I said it wasn't a good conductor. Just because something isn't a good conductor doesn't mean it's a really good insulator.
And I'm still not entirely convinced that your safety ground is just stuck into the dirt with no other connection to the power grid except through the ground to the power plant's earth ground.
Can you see if you can dig up something on the web detailing how the electrical service panel is wired in Germany?
But your earth stick does not have an infinite area.
Again, here the safety ground isn't just stuck into the dirt. It's tied back to the center tap of the distribution transformer. The only reason there's an actual earth ground at the service panel is for lightning protection.
se
Be resourceful. Use the secondary of a 6.3 volt transformer and hook it to your rods via a series resistor to produce a voltage divider. You're just trying to get an order of magnitude measurement of what the conductance between your ground and your power plant's ground, using an analog that places you right next door to that plant.
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