Fremer's Single-leg panel is absolute tweak bs

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 ...

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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

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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.

 

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@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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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 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

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@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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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.

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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.

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