Electrical Panel Grounding

Jea - that youtube is exactly what I needed to know. This forum is amazingly helpful because a handful of people, like you, care enough to share.

I live in Denver with my wife, Lori. My system consists of a custom built pre-amp using two B29 tubes and two small front end Mullards. It is with transformer or OTL switchable circuitry, and switchable capacitance so I can tune to the source.
CD's need less and Vinyl more.

The amps are custom made with two 6C33C tubes per monoblock, 4 Mullards for the ancillary functions and a fairly massive output transformer. Class A/B with a solid 60W per side and 5 separate transformers for the various required voltages.

These amps are plenty to power my Soundlab U-2s. I prefer the U-2s 6' x 3' size over its larger brethren. These have been modified is several ways not easy to explain.

All running Audioquest cables, mostly silver over copper. I know that is way more than you asked, but I somehow thought you might find it interesting. One day I do a post on the pictures/system page, as the room is covered with my own acoustic diffusion and absorption panels which were sized and located by ear and trial and error. If you ever want to build your own, I do have some useful tips that will save you from learning the hard way like I did. And they work better than any of the stuff I tried that was made commercially at about 1/10th the cost.

wgutz ,

Thanks for your informative response.

The reason I asked in an earlier post what country you live in is because when I checked your profile, country was listed as N/A. You might want to change that to USA.

Now that I know you live in the US I have a few questions for you regarding the AC power delivery system used to feed your audio equipment.

What manufacture of sub panel are you using? Copper or aluminum bus?

Feeder size wiring feeding the sub panel?

Sub Panel wired 120/240V?

Approximate length of dedicated branch circuit wiring from the sub panel to the receptacle outlets feeding the audio equipment? (Up down and all around)

Type of branch circuit wiring used?
Example:
2 wire with ground NM-B cable? (Romex is a trade name). If romex how was the cabling ran through joists and or wall studs? Though a common bored hole or individually bored holes? If separate bored holes how far apart were the holes apart from one another? There in Romex cables kept separated from one another.

3 conductor MC armor cable? Aluminum or steel armor?

Conduit with wire loosely pulled into the conduit? If this wiring method was used was a separate conduit used for each 120V dedicated branch circuit?

Are all the dedicated circuits fed from the same line, leg, from the sub panel that feeds audio equipment that is connected together by wire interconnects? All fed from Line 1 or all from Line 2. (Not from Line 1 and Line 2.)

What are you using for wall outlet duplex receptacles? Manufacture, style and or series number? Plated contacts? Type of plating?
What material is the supporting back strap made of? Steel? Brass, other?

What are you using for cover plates for the wall duplex outlet receptacles?
Plastic? Flexible nylon? Stainless Steel? Other?

All the above can have an impact on the sound of your audio system.
.

I have learned to appreciate the need for the one point of neutral tie in at the service panel and the tie to ground for lightening. And why the grounds must be tied together for safety,

One theory that lurks is; if all electric power seeks to return to the source, what is that source for the harmonic distortion and noise created by say a neighbors refrigerator or a faulty relay. And what about the energy used in powering a motor. That energy is not returning to the source. And why does the power get so quiet when it is really wet (rain) outside? These are my questions with my thinking that ground may have some influence as the "sump" theory goes. My local friend advocates a ground field of a half-dozen copper clad rods, each with a separate ground wire tie back to the main panel to lower ground resistance. He is a satellite engineer for the railroad, and is personally working on some changes to basic sigma-delta class D technology, so I do have some respect for his opinions.  

My outlets are PS Audio Blaun (sp?) that replace normal outlets with a double box, and have a machined aluminum face plate. They feed into twin PS Audio power regeneration units (one on the front-end and one for the power amps). The feed is not currently from the existing sub-panel and the sub-panel only feeds a set of outdoor receptacles powering the pond and water features that I can completely turn off during listening. So the plan is in formulation. And the sub-panel may need to be redone altogether.  I would only use lager gauge copper wire to create a dedicated audio feed. And historically, I used a metal (wound style) shield for the wiring from the sub-panel to the outlets, I bought my home with the existing wiring in place.

One oddity, at least to me, is that the existing sub-panel has the power take-off from the main panel by using two 20A breakers in the main panel. Both the main and sub-panel are less than 20' from the audio outlets.I always thought you just came off the main bus for sub-panel power.

I look forward to hearing your input.

wgutz,

The lower the Grounding Electrode, ( example, ground rod), to soil resistance the better. IEEE recommends 5 ohms or less, preferably 2 ohms or less.

It’s not the number of ground rods driven into the earth that will necessarily yield a 2 ohm soil resistance. A lot depends on the content/type of soil and soil moisture. Where you live can make a difference. The 4 seasons can greatly impact soil moisture. It is possible a single 5/8" X 20ft driven ground rod will have a lower ground resistance than 6 individual 5/8" X 8ft driven ground rods.

When multiple ground rods are driven into the earth they should all be tied/connected together with a single wire extended and connected to the electrical service entrance neutral conductor. The multiple ground rods then become a single Grounding Electrode.

Harmonics? The earth will not reduce harmonics.

The majority of harmonic noise found on the AC mains in a home are caused by electronic devices found in the home. Seldom will those produced in the neighbor’s house end up adding to the harmonic noise found in your house.


A refrigerator motor does not produce harmonic noise. Now the micro processor that controls the features on the refrigerator can.

Nonlinear loads produce harmonic noise back on the AC mains.
Examples of,

Switch mode power supplies
Light dimmers
Hair dryers
Computers
Variable frequency drive units found on many of the furnaces built today. (Controls blower motor speed)
Dual wattage portable electric space heaters.
CFL and LED lights
Electronic ballasts

//

PS Audio power regeneration units.

Curious, have you ever checked if the outputs of the two units are in phase with one another? If you have a multi meter measure the voltage from the hot contact from one of the output receptacles on one units to the hot contact of an output receptacle on the other unit. If the outputs of the two units are in phase you should measure zero volts nominal. If out of phase you will measure 240Vac nominal.

//

Sub Panel.

Don’t use it to feed your audio equipment. The wire feeding the panel is too small. Use the main electrical panel.

http://www.p3-inc.com/images/grounding_for_pq_wp2016_p3.pdf
.

Testing soil resistivity

http://www.fluke.com/fluke/iden/solutions/earthground/soil-resistivity-method