My old solar PV inverter recently ran out of warranty. It's over 7 years old and things have moved on in the Solar PV world considerably since I originally had my system installed. I decided to go for a general Hifi system power upgrade - so I had 2 new dedicated circuits installed for my hifi - with copper earth stake in the garden and 10mm cabling. One of these circuits is dedicated to my 300B SET amp. Then , I bought a new inverter - a Pure Sine Wave system from Solaredge with a Tesla Li-on 2.4kv battery - included was a Voltage Optimiser that gives me regulated 220v supply.
So now I have a pure 50 hz AC supply regulated at 220v. Worth it ? Well, to start with, I now have no longer have electricity bills (apart for small standing charge and that is paid for by my exporting income). More importantly, my whole system now has high quality AC feeding it - all I can say is WOW ! The only upgrade I have ever made that was better than this is when I went from a small NAD solid-state amp up to a SET - and this upgrade pays for itself (eventually!). Total cost - about £5k, hardly cheap but I now hear my PC-based - tube amplified system at its absolute best. To me, this is worth every penny - I also get MUCH better TV picture....! If you are thinking of renewing your PV system, GO FOR IT !!!
So now I have a pure 50 hz AC supply regulated at 220v. Worth it ? Well, to start with, I now have no longer have electricity bills (apart for small standing charge and that is paid for by my exporting income). More importantly, my whole system now has high quality AC feeding it - all I can say is WOW ! The only upgrade I have ever made that was better than this is when I went from a small NAD solid-state amp up to a SET - and this upgrade pays for itself (eventually!). Total cost - about £5k, hardly cheap but I now hear my PC-based - tube amplified system at its absolute best. To me, this is worth every penny - I also get MUCH better TV picture....! If you are thinking of renewing your PV system, GO FOR IT !!!
I hope you know what you are doing, both from an electrical safety point of view and an audio quality point of view. A separate earth stake can degrade the former while doing nothing at all for the latter.hillbear said:
People who have paid £5k to 'upgrade' their audio system rarely find it disappointing; the placebo effect is strong, especially among people with money to spend.
There is a dangerous tendency to think driving an isolated ground rod is a good idea in audio circles. Specific recommendation oftentimes to keep it separate from the "dirty" ground system at the panel. In fact, it is a code violation to do so.
Not saying this is what you did; I would think a licensed electrician would install things properly, but you have to be careful on audio forums taking grounding advice. You are definitely better off with an electrician (even one who blindly follows code by habit) rather than taking the advice of an audiophile who is fearful of his existing electrode system.
Not saying this is what you did; I would think a licensed electrician would install things properly, but you have to be careful on audio forums taking grounding advice. You are definitely better off with an electrician (even one who blindly follows code by habit) rather than taking the advice of an audiophile who is fearful of his existing electrode system.
Homes/farms on hills at the end of a long low power electrical service often have *****y grounds. A 3 m copper coated rod won't hit the water table, thus the ground is not effective. This is especially a problem in summer or the dry season.
The electrical code doesn't discuss this problem. Grounding & shielding in instrumentation, a technical book I bought in the seventies, does. It came in handy when division headquarters blew up two 100 kw 3 phase generators in a week in August, shorted from one phase to the other. The 14 loads each had it's ground rod tied to the truck frame per regs. But on top of a hill in August, I postulated they didn't have proper ground because the water table was too low. The engineers connected all the truck grounds together in a circle less one segment, and they stopped blowing generators.
The electrical code doesn't discuss this problem. Grounding & shielding in instrumentation, a technical book I bought in the seventies, does. It came in handy when division headquarters blew up two 100 kw 3 phase generators in a week in August, shorted from one phase to the other. The 14 loads each had it's ground rod tied to the truck frame per regs. But on top of a hill in August, I postulated they didn't have proper ground because the water table was too low. The engineers connected all the truck grounds together in a circle less one segment, and they stopped blowing generators.
> I haven't posted here for a while - don't think I will bother again !
I know the feeling.
The rod in the garden bothered me. As it was installed by UK licensed electricians, I kept quiet. IIUC, in the UK you are *sometimes* required to take company Earth. Which may not be exact-same potential as your garden earth.
The US has a legacy mixed system. Our "Neutral" is grounded along the street-poles. We are required to connect this to a dirt-rod (or other) where service enters the building. This one-point is then split to separate Ground and Neutral conductors inside the building.
I think it is hard fro anybody to play "expert" without walking the land and knowing the power company's work.
At my house, due to the too-long wire from the street, I have "significant" current on my ground rods, and 1V-4V of difference of potential. When the cable TV was not bonded to power ground I had significant hum-bars in TV (even on Digital!), and certain channels would not come in. Also hum in the telephone. Since I jumpered all services (using recent NEC revisions to guide me) the hum is gone. I still have 1V-4V between power "ground" and dirt away from a dirt-rod, "significant" but not "objectionable" current (far-far under 1A).
Ground rod effects vary widely. I believe I can not "do anything" with dirt rods on my land because it is all rock a couple feet down. I now have five dirt-rods, none fully NEC-compliant because of rock. I estimate (from tests) my on-site to-earth resistance is still over 20 Ohms. The power company source impedance is near 0.4 Ohms, so my green wires do what the company does, do not follow my dirt. I put in dirt-rods as convenient mainly because some jerks here steal the ground wires off the poles. If someone took-out my whole street, we would be down to only the at-house grounds.
I know the feeling.
The rod in the garden bothered me. As it was installed by UK licensed electricians, I kept quiet. IIUC, in the UK you are *sometimes* required to take company Earth. Which may not be exact-same potential as your garden earth.
The US has a legacy mixed system. Our "Neutral" is grounded along the street-poles. We are required to connect this to a dirt-rod (or other) where service enters the building. This one-point is then split to separate Ground and Neutral conductors inside the building.
I think it is hard fro anybody to play "expert" without walking the land and knowing the power company's work.
At my house, due to the too-long wire from the street, I have "significant" current on my ground rods, and 1V-4V of difference of potential. When the cable TV was not bonded to power ground I had significant hum-bars in TV (even on Digital!), and certain channels would not come in. Also hum in the telephone. Since I jumpered all services (using recent NEC revisions to guide me) the hum is gone. I still have 1V-4V between power "ground" and dirt away from a dirt-rod, "significant" but not "objectionable" current (far-far under 1A).
Ground rod effects vary widely. I believe I can not "do anything" with dirt rods on my land because it is all rock a couple feet down. I now have five dirt-rods, none fully NEC-compliant because of rock. I estimate (from tests) my on-site to-earth resistance is still over 20 Ohms. The power company source impedance is near 0.4 Ohms, so my green wires do what the company does, do not follow my dirt. I put in dirt-rods as convenient mainly because some jerks here steal the ground wires off the poles. If someone took-out my whole street, we would be down to only the at-house grounds.
It is illegal in the US national electrical code to have separate UNBONDED ground rods. I assume most developed countries have similar laws and codes. In the USA all ground rods must be bonded by a #6awg wire minimum.
One major danger is a lightning strike. Lets say on a rainy night there is 5000 ohms between your two ground rods. You get a lightning strike to ground near by. How much voltage and current can build up between those two ground rods? Your audio system is grounded to the "clean ground". The cable TV box is grounded to the building electrical ground.
Now how much voltage and current is going to flow through the shields of your AV cables?
A fire breaking out is very likely!
One major danger is a lightning strike. Lets say on a rainy night there is 5000 ohms between your two ground rods. You get a lightning strike to ground near by. How much voltage and current can build up between those two ground rods? Your audio system is grounded to the "clean ground". The cable TV box is grounded to the building electrical ground.
Now how much voltage and current is going to flow through the shields of your AV cables?
A fire breaking out is very likely!
Tune In....
If the AV/hifi is powered via a suitable isolation transformer, there there should be no problem with AV/hifi system dedicated earth stake.
This gives opportunity to select particular placement of the earth stake.....think earth energies...Hartman Grid, Curry Grid, Geopathic Lines, Vortices etc.
Dan.
If the AV/hifi is powered via a suitable isolation transformer, there there should be no problem with AV/hifi system dedicated earth stake.
This gives opportunity to select particular placement of the earth stake.....think earth energies...Hartman Grid, Curry Grid, Geopathic Lines, Vortices etc.
Dan.
> It is illegal in the US ..to have separate UNBONDED ground rods. I assume most developed countries...
"all the work was carried out by certified electricians !"
This is a non-trivial statement. We know that much jackleg wiring happens in the US, and sometimes by licensed electricians. In the UK the training is more thorough and the work is much better tested and inspected. US workers don't routinely even use an ohmmeter, in the UK new/major work is subjected to a megger test to not only prove no shorts, but to prove no weak insulation. The grounding provisions vary, and my impression is that the UK's BS rules are more complete than the NEC's.
"all the work was carried out by certified electricians !"
This is a non-trivial statement. We know that much jackleg wiring happens in the US, and sometimes by licensed electricians. In the UK the training is more thorough and the work is much better tested and inspected. US workers don't routinely even use an ohmmeter, in the UK new/major work is subjected to a megger test to not only prove no shorts, but to prove no weak insulation. The grounding provisions vary, and my impression is that the UK's BS rules are more complete than the NEC's.
In the UK we have three common earthing systems, although there may be others.
See http://rsgb.org/main/files/2012/06/emc-leaflet-07.pdf for a brief description. This is aimed at radio amateurs, but the safety issues would be the same for audio. When it says "RF earth" it means a piece of metal in the garden.
See http://rsgb.org/main/files/2012/06/emc-leaflet-07.pdf for a brief description. This is aimed at radio amateurs, but the safety issues would be the same for audio. When it says "RF earth" it means a piece of metal in the garden.
> See ... for a brief description.
Thanks very much. This is the clearest description of TN-S and TN-C-S, and TT, that I have ever seen.
US wiring would generally be TN-S-C.
> "RF earth" it means a piece of metal in the garden.
Works for radio workers. Their frequencies start FAR above power-line frequency, and are normally well separated by caps and chokes. They can perfectly well take one "ground" on power and a "garden rod" to reference their radio antenna.
Audio extends down to, even a bit below, power-line frequencies. We can't use L-C filters to keep our power-common and audio-common separate.
Thanks very much. This is the clearest description of TN-S and TN-C-S, and TT, that I have ever seen.
US wiring would generally be TN-S-C.
> "RF earth" it means a piece of metal in the garden.
Works for radio workers. Their frequencies start FAR above power-line frequency, and are normally well separated by caps and chokes. They can perfectly well take one "ground" on power and a "garden rod" to reference their radio antenna.
Audio extends down to, even a bit below, power-line frequencies. We can't use L-C filters to keep our power-common and audio-common separate.
IME, the American electrical code is one of the toughest. I was on a commercial project in London, a TV broadcast facility, and they were running what is basically Romex in the ceiling cavity for all circuits large and small. I also noticed their device boxes have very little room for wiring and would never pass box fill requirements in the USA. They also don't have city/county employed inspectors. The electrical contractor is responsible for all safety checks. I'm quite sure the British are honest people but really, isn't that like letting the fox guard the hen house?
I was also in the Frankfort Germany air port and they were doing some expansion. What I saw in the ceiling would never pass in the USA.
We do have inspectors employed by the local government, but they cover all aspects of the building regulations not just electricity. It is normally expected that a competent electrician who has been properly trained and accredited will be able to sign off his own work and issue a certificate, but the local authority can inspect the work (although rarely does so). Until maybe 10 years ago it was legal for a householder to do much of his own wiring, but now only certain minor work is allowed.
Different countries have different rules. I guess that in part they are based on avoiding accidents which have been seen in that country in the past.
Different countries have different rules. I guess that in part they are based on avoiding accidents which have been seen in that country in the past.
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