Fremer's Single-leg panel is absolute tweak bs


So a few months ago a video appears on Youtube with Michael Fremer and some electrical contractors installing a custom electrical service and extravagant ground rod array.

OK, but the one thing about it that’s absolute unnecessary tweaky BS is the idea of running a single leg to a sub panel, as well as only using one leg for the audio equipment in it. Who ever thought this was a good idea? It isn’t.

If you really want to get as high-end tweaky as you can this is the absolute wrong way. Run 6 gauge or larger to a sub pane.  In that sub panel you locate a 220V to 120V step down transformer and keep everything balanced all the way to the outlets. That is the best of all worlds.  High noise rejection, meets code, balanced current draw from both legs and extremely low voltage drop from the utility pole to the outlets.

Another good alternative is to run 220V to a wall outlet, and use a high quality step down transformer there. A 220V/30A circuit becomes 60A at 120V output. Running high voltage as close to the outlets as possible doubles your wire gauge effectiveness.

 

 

erik_squires

I agree with your strategy.  Not sure about the local step down transformer.  Do you have an example of one you think is good quality?  thanks.

Post removed 

Not sure about the local step down transformer.

By using this strategy, you maintain a balanced line from the power pole all the way to your outlet AND you cut the voltage crop across the house wiring by half.  Whatever you run, if you ran 10 gauge to 120V, by going to 220V you'll draw half the current, and therefore your 10 gauge wiring will act as if it was doubled.

 

Several of these are good solutions:

 

 

I was done with Fremer when during the breaking news about MoFi he kept saying the guy who asked the question that broke the scandal wasn't a "journalist" so he dismissed it.  He has zero credibility

Fremer has a new Tracking Angel video he shot of his listening room and current system. Available for viewing on YouTube.

@johnah5 Wrote:

I was done with Fremer when during the breaking news about MoFi he kept saying the guy who asked the question that broke the scandal wasn't a "journalist" so he dismissed it.  He has zero credibility

I agree!

Mike

For a residential dwelling unit in the US a hard wired 60/120V balanced power system is not NEC or AHJ (AHJ, in most areas in the US) code compliant. If a person can get a electrical contractor/electrician to install and wire one into the electrical system of a residential dwelling unit he will do so without pulling an electrical permit.

 

Quote:
"60/120V Symmetrical (Balanced) Power Systems Per NEC 647.1 (2008) the use of a separately derived 120 volt, single phase, 3-wire system with 60 volts between each of the two ungrounded conductors and ground is permitted for the purpose of reducing objectionable noise in sensitive equipment locations, providing the following conditions are met:


1. The system is installed only in commercial or industrial occupancies


2. The system‟s use is restricted to areas under close supervision by qualified personnel.


3. All other requirements in NEC 647.4 through 647.8 are met.


In a 60/120-volt symmetrical (balanced) power system the load current return path is not a grounded conductor, as it is for the standard 120-volt system. Neutral and safety ground are no longer tied together as in a standard electrical system."

"A major disadvantage of balanced power
systems is the requirement for ground fault
circuit interrupter receptacles (GFCI). These
receptacles can trip due to normal ground
leakage currents."

"When the GFCI receptacles are disabled or
bypassed, the system becomes an
electrocution hazard!"

"Since the noise reduction achievable with this scheme is typically only 6 to 10 dB, symmetrical (balanced) power transformers are not a cost-effective method of reducing system noise. The primary benefit (reduced common-mode noise) is due to the fact that these systems are inherently isolation transformers, whether the output is balanced or not. A standard, unbalanced shielded isolation
transformer will do nearly as well without the disadvantages of a balanced output power transformer."

Pages 26 - 27

Power Distribution and Grounding of Audio, Video and ...

/ / / / /

Quote:

"So-Called “Balanced Power”
Properly called SYMMETRICAL power
Has very seductive intuitive appeal
NOT similar to balanced audio lines in any way!
Uses transformer having 120 V center-tapped secondary
Both line and neutral output blades are energized at 60 V
Although advertising often implies endorsement, NEC seriously restricts
its use – because it’s potentially dangerous!
ONLY FOR PROFESSIONAL USE
NOT to be used with lighting equipment, especially screw-base bulbs
MUST have GFCI at outputs
Only technical function is to reduce leakage currents
Leakage currents are trivial system noise sources
Reported noise reduction generally less than 10 dB
Any real benefit likely due to its clustered outlets."

"The theory is pretty simple: if symmetrical (equal but opposite instantaneous polarity)
AC voltages are applied to equal-valued capacitors, say C1 and C2 above, the two
current flows would also be equal but opposite and cancel each other ... no net
current into safety ground. But leakage currents flowing in safety ground
wiring are not a significant source of ground voltage differences ... as so
many apparently believe."

An Overview of Audio System Grounding & Interfacing 9/4/2012
Bill Whitlock

pages 201-202

An Overview of Audio System Grounding and Interfacing

/ / / / /

Another problem if a 60/120V balanced power system is hard wired to the electrical system of a residential dwelling unit according to NEC as well as most AHJs in the US most 120V branch circuits shall be AFCI protected. Yes an audio room that would apply... The 2 pole circuit breakers in a "wall mount" hard wired 60/120V balanced power system are not AFCI circuit breakers. I doubt they would even function if they were tried. They are not designed, manufactured, or Listed, to be connected to a 60/120V symmetrical power system.

 

.

Thanks for the clarification, @jea48

So, we can't use an in-panel balanced power/symmetrical power provider, but we CAN use a step down balanced power converter so long as it's plugged in.

Is that how you read it?

Best,


Erik

Quote:
"60/120V Symmetrical (Balanced) Power Systems Per NEC 647.1 (2008) the use of a separately derived 120 volt, single phase, 3-wire system with 60 volts between each of the two ungrounded conductors and ground is permitted for the purpose of reducing objectionable noise in sensitive equipment locations, providing the following conditions are met:


1. The system is installed only in commercial or industrial occupancies


2. The system‟s use is restricted to areas under close supervision by qualified personnel.


3. All other requirements in NEC 647.4 through 647.8 are met.

@jea48

i use an Equi=tech 10WQ Wall Panel System which does use balanced power. my electrical contractor was fine installing it since it was in a separate building, for a dedicated room "only" resembling a commercial installation. i called it my ’studio’ to my contractor.

no water in the room, or children in the room. it was a purpose built room. which met the code. only my system gets plugged into that panel.

as far as system performance, i have dirty power outlets around the room and it’s easy to compare them to my Equi=tech balanced outlets, and it’s quite a bit better sounding both for sources and amps. i’ve had a few manufacturers bring gear skeptical about my isolation transformer or balanced power. they left no longer skeptical. why my separate isolation transformer sounds better is a fair question. i have my own transformer at the street, and am in a newer development in the mountains. so you would think my regular power would be pretty good.

PS - I am pretty sure they make 2-pole CAFCI breakers these days, but if symmetrical power is not allowed at a residential wall outlet then there’s no getting around that in the NEC.

i will invite 'Rex' who is a local friend, and also the consultant to Michael Fremer who appears in the video, to join this conversation. i'm not qualified to debate these issues, i just listen. but he is for sure.

As for Fremer’s audio room power system:

A lot of audiophiles use a sub panel to feed their audio equipment. I would guess in most cases the sub panel is wired 120/240V. I would also guess that most audiophiles, not all, feed all there equipment, that is connected together by wire interconnects, to branch circuit breakers fed from only 1 Line. All from Line 1 or all from Line 2. Not from both. No different than if multiple 120V dedicated branch circuits were ran from the main electrical panel.

FWIW in Fermer’s case, I doubt if the total used listening audio equipment continuous FLA equaled more than 12 amps tops.

Other things found in a home that can draw 12A at 120V continuous:

Portable plug in Vacuum cleaner.

Central Vac system.

1500 watt 120V plug in electric space heater.

120V window A/C unit.

Above counter plug in toaster oven.

Some hair dryers. We have a 1875W hair dryer. FLA 15.63A.

I’m sure there are other 120V devices, appliances, equipment, that could be added to the list.

/ / / /

Any of you guys watch this interview video of Caelin Gabriel CEO of Shunyata?

Where does most of the noise come from on an audio system? The circuit designer,(maybe not all), dump’s it on the chassis of the equipment. Makes sense to me...🤔

 

I would really appreciate it if a new thread were created for discussions of circuit vs. chassis and safety grounds instead of intermingled here.

Lets keep this narrowly focused on discussions of 1 leg or 2 to a panel, and best practices. 

Thank you very much.

i use an Equi=tech 10WQ Wall Panel System which does use balanced power. my electrical contractor was fine installing it since it was in a separate building, for a dedicated room "only" resembling a commercial installation. i called it my ’studio’ to my contractor.

no water in the room, or children in the room. it was a purpose built room. which met the code. only my system gets plugged into that panel.

my barn also has a ’’dirty’ power separate panel.

@mikelavigne,

Sounds familiar...

Didn’t you PM me when you were looking at building a separate structure for your audio system asking about how you could get around NEC and the AHJ so you could install a hard wired 60/120V balanced power system in a residential dwelling unit?

Just going from memory I advised you to tell the builder to pull the permit for a light commercial occupancy which would be used as recording studio. Was that you that contacted me?

Jim

.

@jea48

hi Jim,

i do not recall talking to you. but i might have posted on the subject and you might have had a recommendation. or over the years we might have crossed paths about it. many have asked me about my Equi=tech.

added note; after thinking more about it, my recollection is that you and i did discuss either on line or in a PM about the issue of permitting after the fact. i did not get a permit for various reasons, but my contractor said he did not see any issue getting one if we had chosen to do so.

my room project was in 2004, at that time my room designer spec’d an Equi=tech Wall Panel System, but my budget did not allow for it, so i had a conventional 70amp panel installed as a place holder with the ground rod and 125 feet of copper in ground conduit from my main panel in my garage from my house.

my designer was Chris Huston, who had been designing mastering and recording pro studio installations for years.

then in 2010 i was able to have the 10WQ Wall Panel system installed and hooked up to my in place grid. it was a big jump up.

I looked up the numbers.

If you run a 10 gauge wire to a 220V outlet, and then use a step-down, balanced transformer that 10 gauge wire will perform almost like 7 gauge. 

That in combination with the noise rejection of balanced power transformers is a huge win.

The common mode (both legs) noise rejection is huge, and the additional R and L in the transformers will offer additional (differential) noise rejection as well as  some voltage sag protection.

https://www.engineeringtoolbox.com/copper-wire-d_1429.html

@jea48 Thx for posting that video with Caelin Gabriel. Very informative about signal ground vs chassis ground. It helps explain why different components respond differently to various grounding solutions. As with everything else in high-end audio, it can become as complicated as you’re willing to deal with - and/or - budget will allow.

I designed the electrical distribution for Fremers house.  I have done as such for 80 or so houses.  There is a lot of correct information in this thread.  And some that is wrong.  Jea48 is correct on most everything he says.  You have to look at it from a Code perspective.  Mikelavigne setup using Equitech is code legal and very safe.  It is not in a residence.  A residence is any structure where sleeping, bathing and cooking are available.  Mikes stand alone structure only has sleeping and bathing so its not a residence.  As such he does not need AFCI.  There is no kitchen in the listening room so he does not need GFCI.  Technical power 60/60 is not legal in a residence, but it can be used in non residential structures.  The outlets are supposed to have a label stating their is voltage on the neutral to keep an electrician safe who might otherwise feel it is not a live wire.

I fully agree a good isolation transformer is a must for most all high quality installation.  I am a representative for Torus Power.   It is the only product line I carry outside the panels and grain oriented twisted wire I make.  I selected Torus as their isolation transformers have 120 or 240 volt in and 120 or 240 volt out, up to 100Amps.  

I am going to circle around a little here.  As for Fremers with a single leg of power to your gear.  You absolutely only want to use 1 leg to ensure the voltage to all equipment is exactly the same.  It is very audible when 1 leg is used compared to 2.  If you look at the way electricity works in a wire, there is a halo of magnetism and electrons that emanate out from the wire. EMF.  That halo will interact with any other wire with voltage and current in close proximity or with magnetic metal such as a steel beam, steel gas pipe, steel wall framing, EMT tubing, Steel MC cable jacket.  I don't want a  second wire in a pvc pipe that is not going to be used interacting with the primary phase conductor and neutral, so I left it out a Fremers.  I was not able to get a letter from SqD stating their panel is rated to operate at 120 volt only, so we put it in later.  In response to this hickup, I now have a fully custom panel manufactured for me that is pure uncoated copper on the phase, neutral and ground and the panel is listed and UL labeled for 120 volt only.  You can not put 240 volt to this panel.

Circling back around to isolation transformers.  This is the perfect marriage of technology. Torus makes a large 100A isolation transformer that puts out a single leg of 120 volts with a neutral and ground that feed directly to my all copper panel that is listed and labeled for 225A at 120 volts only.  This is also important in that, lets say every 120 volt breaker in your house has to be an AFCI.  There is no AFCI that is rated for 60/60 technical power.  I believe there are GFCI that are rated for 60/60 volts. They defiantly work at 240 volt as that is what powers my hot tub.  It really comes down to, is there enough demand the manufacturer will spend the money to get it tested and listed, and can they sell enough to make it worth their while.  

I do not like multiple isolation transformers.  You will never have the exact same voltage out of 2 separate transformers.  You might at well run 2 phases.  And from extensive testing in the field, I can tell you, you only want 1 phase.  Period.

I really don't understand where Erik gets the idea the grounding I did was extravagant.  Its code???????  Go read NEC Article 250. 

I started my business for a couple reasons.  The first was I am an audiophile and I was seeing so much Crap misinformation on the internet if pissed me off.  I wanted to set people straight and get correct information out there. 

The second was the level of performance gains I was able to get at my own and at friends houses.  I have been an electrician since 1995.  I have worked in hospitals, data centers, towers, industrial facility.  I have been a PM and estimator for a large union contractor.  I have worked for Square D and still have good friend there. I have owned my own union electrical shop and employed people wiring restaurants and high end residential homes.  I have been around a bit.  As such, I was able to start tweaking the power to my stereo and listening to the results.  Once I had a good bearing and assumptions of what and why certain techniques worked better than other, I took the lessons to friends houses.  I would apply changes one at a time and have the owner listen.  Then I would come back and make another, and so on.  Through about 5 houses I validated some fundamental techniques that brought very high performance to their audio and video systems.  They always noted on the side their TV were much more vivid and alive.  

Don't think I am doing this all on my own either.  Technically all I have done is drill down on precision installation of fundamental principals of electron flow.  I have read countless white papers and books on the subject.  I have take specialized classes on grounding. I do what I can to keep up to date with code changes and what manufacture are producing that work well with my techniques.  There is nothing vodo or tweak in what I do.  It is applying stringent techniques that are based on fundamental electron theory formulated over hundreds of years by people such as Edison and Tesla.  Then refined by people such as Bill Whitlock or Ralph Morrison.

Fremers electrical kicks butt.  He had Gryphon monoblocks there to review and the Gryphon rep said his was one of the only rooms he has been in that the amps were not starved.  Fremer also has grain oriented solid core 10 awg branch wire.  I heard about this wire through Garth Powell.  Garth made the wire for Fremers room.   I looked into what it was and why it occurs.  I kept some left over wire from Fremers and made a tool with it where I can test wire myself and determine the crystal structure in it as pulled through dies and sized to its final gauge.

All things matter to some degree or anther in audio.  Some more so than others.  If you want to say its all hogwash and power your system of a 14 awg wire that feeds the whole living room and maybe the lights too, go ahead.  You can still enjoy your stereo.  If you just put a 12 awg dedicated wire to the rack you will hear it.  Make it a 10 you will hear it again.  Grain orient and twist it and you will hear it again.  If you house is grounded per code minimum by a guy who did not really think through grounding, and 0 electrician have, you might hear a large difference when its done right.  Or, you might hear little to nothing.  It depends on how poorly it was done in the first place.  When I design a house I look at everything.  I look at the service strike, the meter equipment on the wall, the panels, how those panels are made up, the grounding, the branch circuits, how they are run, the boxes in the wall (what and how they are landed) the duplex wiring, the integration of data for streaming.  Get any of this less than ideal and sure, its going to work.  But your leaving a little performance here and there.  Leave enough out or make mistakes and you could end up develop ground loops or injected noise issues you don't want. 

Per the OP post, the grounding I did is code minimum, but applied very well.  If you have a stereo with a stand alone preamp, amps, server, DAC, phono equipment, you want it all on 1 phase.  If you only have a headphone rig or an integrated unit and speaker, then you only have 1 plug.  It does not matter the phase you select.  Most of the noise is on the neutral so all this talk about finding the quiet phase is kind of mute.  Ground the house properly and you will shunt most noise to earth.  Yes you can get rid of noise.  Noise is not just RF.  Its Milivolts and possibly volts of current riding around on your equipment. That noise and some RF will go to earth if you put your panels together, ground and run your branches properly.

Rex

  

@kingrex

Rex post + 1

Just to clarify a few points.

1) you said:

Mikes stand alone structure only has sleeping and bathing so its not a residence. As such he does not need AFCI. There is no kitchen in the listening room so he does not need GFCI. Technical power 60/60 is not legal in a residence, but it can be used in non residential structures.

To be clear GFCI protection is required on a 60/120V symmetrical power system (so called 60/60V Balanced Power System) for the branch circuit wiring. I know you know that,... but it needed to be pointed out here on this thread for the DIYers.

Oh by the way my reference to AFCI branch circuit protection was just another code violation IF a hard wired 60/120V symmetrical power system was installed in a residential dwelling unit, as I am sure you know. NEC code care less if it’s an audio room.

2) You said:

Per the OP post, the grounding I did is code minimum, but applied very well.

It should be pointed out NEC only requires, as you know, a rod to soil resistance of 25 ohms or less. As you know that is way too high. IEEE the Emerald Book recommends 5 ohms or less. (For commercial/industrial facilities). Far better for lightning protection than 25 ohms. If I remember correctly in the Fremer video someone saying the grounding electrode system soil resistance was a 1/2 ohm... Outstanding! That’s probably better than a lot of industrial facilities in this country.

3) Finally This. You said:

Ground the house properly and you will shunt most noise to earth.

Here I will have to disagree. The Earth does not possess some magical mystical power that sucks nasties from an audio system.

I used to think as you do that noise can be diverted to mother earth until I was called out on it on AA many years ago. Well I had to prove I was right, correct? Good luck proving it...

I’ll leave you with this:

Grounding Myths

From Henry W. Ott’s "Electromagnetic Compatibility Engineering"

3.1.7 Grounding Myths

More myths exist relating to the field of grounding than any other area of electrical engineering. The more common of these are as follows:

1. The earth is a low-impedance path for ground current. False, the impedance of the earth is orders of magnitude greater than the impedance of a copper conductor.

2. The earth is an equipotential. False, this is clearly not true by the result of (1 above).

3. The impedance of a conductor is determined by its resistance. False, what happened to the concept of inductive reactance?

4. To operate with low noise, a circuit or system must be connected to an earth ground. False, because airplanes, satellites, cars and battery powered laptop computers all operate fine without a ground connection. As a mater of fact, an earth ground is more likely to be the cause of noise problem. More electronic system noise problems are resolved by removing (or isolating) a circuit from earth ground than by connecting it to earth ground.

5. To reduce noise, an electronic system should be connected to a separate “quiet ground” by using a separate, isolated ground rod. False, in addition to being untrue, this approach is dangerous and violates the requirements of the NEC (electrical code/rules).

6. An earth ground is unidirectional, with current only flowing into the ground. False, because current must flow in loops, any current that flows into the ground must also flow out of the ground somewhere else.

7. An isolated AC power receptacle is not grounded. False, the term “isolated” refers only to the method by which a receptacle is grounded, not if it is grounded.

8. A system designer can name ground conductors by the type of the current that they should carry (i.e., signal, power, lightning, digital, analog, quiet, noisy, etc.), and the electrons will comply and only flow in the appropriately designated conductors. Obviously false."

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Lets keep this narrowly focused on discussions of 1 leg or 2 to a panel, and best practices. 

I've always liked the logic of using two legs to share (and halve) the current load, as it pertains to larger motors in a residential circuit.  Each leg is much farther below it's theoretical current limit.  Not sure if or how any of that translates to sound quality, but the reduced current flow per leg still makes sense to me regardless of the application. 

Jea, I have measured with a meter a reduction in noise in a panel when its grounded properly. I have eliminated certain noise. Yes you can shunt noise when you ground properly. Grounding is far more technical than a rod in the earth.

But look.  I'm a business.  Its my sole income now.  I laid off all my employee and stopped doing restaurants and houses.  For more reasons than just being a crazy audiophile.  If you want to really understand grounding you need to do the work . Take the Lyncole classes.  Read the Sores books.  Read the Morrison books.  Watch the Holt Video.  Talk to other people who do as I do.  There are a couple others out there.  For the most part they do recording studios.  There are business dedicated to grounding and they get big money to tell data center and hospitals, labs, military etc how to ground properly.  Finally, go out and apply what you learn.  Measure it.  You can get rid of noise if you do it right.  This idea you can't is people not doing it right. 

If you really want to scratch your head, prove to an engineer a ground box like Entreq or Altaira reduce noise.

I I'm not an electrical engineer or electrician just a audio guy trying to get better sound. This is my take!

Save money by dumping the step down transformer as it adds more noise. In the USA residential single phase split 120/240 Volts, 240 Volts is more efficient then 120 Volts. 240 Volts is half the amps as 120 Volts. 240 Volts is balanced power right from the pole transformer to your house. In my opinion your audio gear will sounded better on 240 Volts then 120 Volts. 😎

Mike

@kingrex said:

I have measured with a meter a reduction in noise in a panel when its grounded properly. I have eliminated certain noise.

I have no doubt in what you say. But show me the circuit. Here is the circuit as I see it.

The EGC, IF used, >>> to the service equipment grounded conductor >>> to the neutral of the split phase secondary winding of the power transformer. There, some, of the noise energy is dissipated in the winding in the form of heat.

Mother Earth is not involved.... Show me the circuit if you think it is. Please provide any credible proof from someone like Henry Ott, as an example, who says noise can be "shunted", diverted, to mother earth. Show me the circuit if you think it is. You said, Quote: "Read the Sores books. Read the Morrison books." .... How about a quote, a White Paper, of Morrison’s that will backup your thinking.

Those in authority need to stop telling audiophiles noise on a circuit ground can be shunted, diverted, to earth. I still read current posts where audiophiles are driving a rod outside their audio room using it to replace the branch circuit EGC. Dangerous as Hell... And in the case of a bolted ground fault it will never trip the circuit breaker in the panel. Never...Works great for hunting fish worms though.

Finally this:

If you really want to scratch your head, prove to an engineer a ground box like Entreq or Altaira reduce noise.

I know nothing about the Entreq...

What I know about the Shunyata ALTRAIRA Ground System I learned from watching the video I posted above. What Gabriel has built, and his explanation of how it works, makes sense to me. He uses individual filters that are connected, to each ground post on the back of the box that are then connected to a common ground conductor. So all the filtered grounding posts are connected together.

He has two boxes. One for the Chassis ground and one the signal circuit ground. NOTE no where in the video does he promote floating, disconnecting, the EGC from any audio equipment that uses it. If fact, as I remember from watching the video, He says, and rightly so, the electrical service connection to mother earth is for lightning protection. Not for, shunting, diverting, noise to earth...

He didn’t fully explain, unless I missed it, how he treats the chassis of Class II double insulated audio equipment where an EGC is not used. That equipment is different... That equipment the Signal ground and DC B -, is connected directly to the chassis. One mistake I caught was him saying tube equipment designers connect the signal ground and DC B - directly to the chassis. That’s not true. Some might, but not all.

What I did find interesting, if true, some equipment noise the rectifier(s) make in the DC power supply(s) circuit designers dump it onto the chassis. Maybe Gabriel could show them how to install a filter between the signal ground, DC B - , and chassis. That would solve a lot problems.

.

Jim

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I really don’t understand where Erik gets the idea the grounding I did was extravagant. Its code??????? Go read NEC Article 250.

Extravagant is the difference between what the NEC would require (minimum 2) and what was installed.

As in many cases, the NEC often specifies the minimum requirements, not the maximum. You can be NEC code compliant and extravagant at the same time. But really, that entire post above should be memorialized.

 

 

^ + 1. Print it out before it gets deleted! ;-) I'm gonna, then add it to my reference technical material.

kingrex said:
I really don’t understand where Erik gets the idea the grounding I did was extravagant. Its code??????? Go read NEC Article 250.

erik_squires said:

Extravagant is the difference between what the NEC would require (minimum 2) and what was installed.

@kingrex only installed one ground rod, 20ft long into the earth. He then tested the rod to soil resistance using the proper test equipment. kingrex met the requirements of 2020 NEC 250.53 Exception.

Exception: If a single rod, pipe, or plate grounding electrode has a resistance to earth of 25 ohms or less the supplemental electrode shall not be required.                 

Kingrex's use of the Cadweld System (Trade Name for a exothermic welding process) is unusual for a residential dwelling unit but it is a 100% solid conductivity zero resistance connection of the grounding electrode conductor to the grounding electrode, (ground rod). It will be that way forever... Can't say that about an approved ground rod clamp. Remember the connection is buried in the earth below  grade. How often is the connection checked after it is installed?

FWIW The grounding electrode system primary purpose is for lightning protection. It is the foundation for a good system ground connection to earth for an electrical service.

The lower the soil to electrode resistance the faster a whole house SPD will divert a lightning transient to mother Earth.

Also worth noting 25 ohms is to high of a soil to grounding electrode  resistance. IEEE (Green Book) recommends 5 ohm or less for commercial and industrial facilities. Lightning could care less if it's a residential dwelling.

.

 

I have two dedicated power lines to my stereo.  One goes to the two mono amps and one goes to the front end.  I had the two circuit breakers adjacent to each other in my breaker box, which means each one was on a different leg.  I took Kingrex’s advice and moved one breaker so that both dedicated lines are on the same leg.  The stereo sounds better now.  (The white wires and ground wires from each circuit are adjacent to each other on their respective ground busses. Ie. I want the ground wires as close together as possible.)  I’m using 10AWG wire and audio grade outlets.

I wonder if the stereo sounds better now because each leg (120 VAC) is out of phase with respect to the other and so now the amps, preamp and source are all on the same phase.

If there's a solid model or reasoning for using only 1 AC leg that is based on math I'd love to see it.

In Fremer’s case the sub panel could have been wired for 120/240V from the start. All the audio equipment still could be fed from one Line, leg. The electrician would have increased the size of the feeders knowing he would be feeding all the branch circuits from just one Line, leg.

If an isolation transformer was used with dual primary and dual secondary windings and the primary is wired for 240V, and the secondary is wired for 120/240V to feed a 120/240V panel unless the transformer is oversized to feed all the audio equipment branch circuits from just one Hot leg to neutral the audio equipment branch circuits would have to fed from both 120V Hot leg to neutral. Therein the loads some what balanced across both 120V legs.

An example, a 7.5KVA transformer is selected for use. The transformer has dual windings. Each winding is good for half of the 7.5KVA rating. 7500VA / 2 = 3,750VA at 120V each. 3,750VA / 120V = 31.25A.

So if the secondary is wired for 120/240V, (two windings are wired in series), and only one 120V hot leg to neutral was used, (Only one 120V, 3,750VA winding), it’s only rated for 31.25A max... If both legs were used to feed the audio equipment the full 7500KVA rating of the transformer would be available. 31.25A on one leg and 31.25A on the other. But the audio equipment would be fed from both legs. Not good for audio equipment that is connected together by wire interconnects... (One Hot 120V leg to the other Hot 120V leg measures 240V.)

If the two secondary windings are wired in parallel the full 7500VA is available.

31.25A + 31.25A = 62.5A Max available.

So in this case the electrical panel would be wired for 120V only.

.