I am not familiar with the term "star ground". Can you explain what it is your trying to do or achieve ? Maybe from your description, we might be able to understand a little better. Sean
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Star grounding, Sean, I think means, that you run a ground from each of your components to one single grounding point.
Correction much appreciated, should I be wrong. |
Yes Detlof is right. There have been several lengthy discussions about how to do this, problems with doing it with in Electical Codes, etc. I'm sorry I don't have the references but several electrical (as opposed to electronics) professionals have weighed in and you should really read these. I use a star ground and it really improved things but I have severe electrical quality AND noise problems. |
"Star Grounding" is common and the only way to fly for a noise free mobil audio installation. Star grounding means grounding all components to a central ground as the others have mentioned. But for best results all lenghts of ground wire SHOULD BE OF EQUAL WIRE AND LENGHT. |
Forgot to mention that its important not to have any of the grounds cross over one another. Picture the center of a star as the grounding point and the points of the star as the ground leads. Thus "Star Grounding". I'm sure you can take it from here Sean. Mikec |
Mike--when you say not cross each other, you mean physically, I assume? And thanks, everyone, for the advice. I'm going to star ground my outlets.
See what you think of this: I will have the electrician--helieve it or not, he's more than willing to do all this, unlike some other electricians I've talked to who think it's all nonsense--run a copper grounding rod into the earth. I'll run separate wires of equal length to the grounding rod from my outlets. Then I'll also ground the main breaker box, which is currently only grounded to the copper water pipe, with another wire running from the pipe to the grounding rod. I'm doing this because I've been told that everything should ultimately be tied to the same grounding rod? Does everyone agree?
Or should I just run the three outlets from the subpanel back to the grounding rod? |
Gladstone i feel its best for someone with more knowledge to answer your questions. I beleive this is against all code enforcement. I've seen star grounding the components (as oppossed to "Floating the Ground") but not the AC outlets. |
I actually don't think it's against code, as long as you go to one grounding rod. |
Mikec, thanks, I did not know about the equal length and the wires not touching each other. Regards, |
My star ground configuration goes to a ground rod outside the listening space but does not ground to the panel. This is against code which calls for a ground at the main box. The major reason for this configuration is my electricity is suppied by the oldest underground residential service in California (1925) and the noise on the circuits is unbelievably bad. |
Some years back a manufacturer named Audio Control (well known for their EQ's and Crossovers, mainly for car audio) offered a White Paper on the subject of "Star Grounding" to anyone who requested a copy. Don't know their URL but maybe the company still offers the White Paper on the subject. The company is still going strong, so getting in touch with Audio Control shouldn't be a problem. Hope this helps anyone. |
info@audiocontrol.com (425-775-8461) Mikec |
Read this first: http://www.mikeholt.com/Newsletters/ig2.htm
and: http://www.engineeringharmonics.com/papers/p_gupdte.htm
If you have a ground rod for your system that is seperate from your main ground you risk large ground potential differances if you have a lightning strike near by or have a ground fault condition on one of your grounds. The code requires that the grounds be tied together. |
The best way to achieve star grounding is to put 3 prong to 2 prong adapters on all of your audio components and then run a piece of 3/4" ground braid from each component's chassis ground to a single tie point and then to your SERVICE BREAKER BOX ground. This method is safe and can eliminate many ground loop problems. |
I really need to say something here. All of your gronding electrodes need to terminate at your main AC neutral in the first means of disconect on your electrical service. This is code period! There is a reason for this. By creating a seperate grounding electrode system for your audio equipment, you have also created a difference of potential in your electrical system. Any surge or noise that is on the line, will follow the grounded conductor (ie neutral) right through your equipment and out to your seperate ground grid. These would normally be handled right at the service entrance. If you want to improve your ground, do it at the service entrance. Your water pipe should bond at the main AC neutral. Any verticle steel posts can be bonded to this point also. The driven ground rods (electrodes) bond to this point. If you have a well, bond it to this point. Everything will reference BACK to this point! Not through it and into your system. Isolated grounds also bond back to the main AC neutral! Ground and neutral are the same potential at the servce entrance for a reason. They are kept apart from there on out. Even in sub panels. Sorry if I sound like I'm venting, but you could cause more harm than good. |
In the interest of not blowing yourself sky high should a lightning transient come slamming in, it seems very dangerous to connect water pipes to electrical ground. Washing hands or showering during a storm could be lethal! |
The water entrance (street side of the meter) is one of the better grounding eletrode sources. Code requires it if it is in your home. |
Talked to audio control and some other electricians who see no problem in establishing independent grounding rod for the outlets. |
Gladstone ---- Great, seem to have your questions answered. |
I agree 100% with mrderrick. What he's basically describing *is a* star ground system. You probably already have most of it established in your house right now. I'm a retired Radio Broadcast Engineer, and I had broadcast towers (that were right next to studio and radio station office buildings) getting struck by lightning at least 12 times a year. Preventing those surges and strikes from blowing up broadcast equipment is the name of the game in broadcasting. That's when a star ground system *really* comes into play, and they are mandatory in broadcast facilities. Those same star ground configurations can however also be applied to home audio systems.
If you really feel the need to make AC earth grounding improvements, I suggest 1) check to make sure everything mrderrick mentioned in his post, you are abiding by, or have incorporated into your AC service. 2) NEVER EVER NEVER(!!) establish a completely separate ground system that is not connected to your AC service entrance panel 3) make sure each AC wall outlet feeding your audio system has a ground wire, fed from the AC breaker box, connected to the outlet's ground/earth terminal 4) if you feel it's necessary, install isolated ground outlets, with a *dedicated isolated* ground wire feeding back to the AC breaker panel 5) add additional ground rods to your already existing outdoor ground rod, or ground rods, and make sure they're ll tied together 6) if you have any, tie all metal rebar building structure to your ground system. I even connect gas pipes to my earth ground systems.
The object is to tie all earth grounds together, preferably at one point (hence the name star ground). I realize we're discussing this to keep our audio system's noise floor as low as possible, but another reason for the star ground, is to keep all grounds at the same ground potential. In some past broadcast facilities, I have seen carbon traces where lightning has arc'd over to a ground of lesser resistance, trying to find a pathway to ground.
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