Dedicated Circuits - Subpanel importance?

@jea48 Thanks so much, very kind of you.

On the other hand, if he's meticulous, and can come into a multi-million dollar home and not damage half of what he touches, he can pretty much name his price.

My son just completed the first phase of his residential electrical education

@vinylvalet

He should use that as a starting point and then try to move to the commercial and industrial electrical wiring industry. That's where the money's at.

I would recommend he start here:

Phoenix Electrical JATC

@oldandslow Thanks for your book recommendations and other sage advice. My son just completed the first phase of his residential electrical education and I'lll share this information with him, especially your emphasis on safety. Like most audiophiles, I know just enough to be dangerous.

@whart I love my hospital grade Hubbell outlets ;-)

I met and for some time knew a guy whose grandfather, named Hubbell, invented the electrical receptacle and pull chain light "switch." In the early days of wiring electricity, they hadn't thought about plugging stuff in as opposed to hard wiring it.  Oh, and turning something on and off? 

My friend had some very nice race cars. Generations later.

The company is still a well regarded supplier of many things electrical. (I like the sunken airport runway lights) :)

*This was an unsolicited message that involved no exchange of consideration with the brand named. :)

Household 120V outlets were not designed for 10AWG wire 

   I disagree see below.

 

 

There are a few manufacturers that do make 20 amp outlets that support 10AWG wire.

If your equipment does not have a cord/cable or, from the the manufacture, is required to have a cord/cable with a 20A plug then it was designed and built to operate and perform properly on a standard 15A, 120V circuit. What makes anyone think that a DAC, CDP, turn table, ETC that draws less than 3As will sound or perform any better on its own 20A circuit. Household 120V outlets were not designed for 10AWG wire and No you Can and should Not have a secondary earth ground off a sub panel - not only will it do nothing to improve your sound, it is dangerous and in most cases illegal.

+++ to oldenslow and the few others here who actually know something about household and commercial wiring.......Jim

 

 

 

Safest bet go buy 

All I have to say is I made a boatload of money in the electrical industry considering all of the big brains telling me I'm wrong. I know NEC sucks and changes almost what seems daily. To all electrical working brothers and sisters please look twice work safe and go home to your families every single night.

With Respect,

C.A. Braden

Grizz (preferred handle)

I had a long reply, but after reading the thread again I deleted it.... Some of you cats are too far out for me to even address let alone have to argue a point.   Anyone claiming to know it all about electricity is the most dangerous person at your home, job site, or utility.  

Work Safely,

Grizz

Retried 

IBEW Superintendent, Foreman, Journeyman wireman, Coal Fired PowerStation Electrician, C&I, and operations tech, and lastly Contractor.

 

 

LET'S TALK ABOUT SOUND and SOUND REPRODUCTION EQUIPMENT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Guys,

When the full 240V secondary winding is used to feed a 240V load the winding works like any other single phase transformer winding.

Things change when 120V loads are connected to L1, leg, and the neutral, and L2, leg, and the neutral. This is where the polarity of each side of the secondary split phase winding gets interesting.

If  L1 to neutral and L2 to neutral loads are exactly the same amperage, zero amps will return on the neutral conductor to the transformer neutral center tap. Example 10 amp load connected to L1 and neutral and 10 amp load on L2 and neutral. Zero amps will return on the neutral conductor to the center tap neutral on the transformer. The two 120V loads will be in series with one another and fed by 240V. If a10A load is connected to L1 and neutral and 5A  load connected to L2 and neutral, the unbalanced load of 5 amps will return on the neutral conductor.

On a single phase dual winding secondary it is important to observe the polarity of the windings when connecting them together.

How it works.

https://www.allaboutcircuits.com/textbook/alternating-current/chpt-10/single-phase-power-systems/

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You are most likely right, but it doesn't seem like it would be a different phase either.

It's AC. There is no polarity per se. The AC waveforms have equal magnitude are out of phase

 

This happens a lot. Re-reading my post concerning the second point that I made, we are saying the same thing in a different way. Once a topic gets to this point, it is best to stay out of it.

 Not sure that you can change the POLARITY of an AC line, since it alternates. 

Seems to me, it would be a change in polarity not a change in phase. A change in phase is a change in timing, like in three phase systems.

A lot of PS Audio is bunk!

 And That you can take to the bank. 

     You can say that again!!

    

A lot of PS Audio is bunk!

 And That you can take to the bank. 

Leg is not synonymous or the same thing as electrical phase.

From an electronics standpoint, residential panel legs are 180° out of phase.

Three phase power is 3x 240 volt 120° apart. Apples & oranges.

 

I believe what I believe, BUT it doesn’t change the truth. It almost depends on which expert you ask about one phase or two going to a residential home. My understanding is this, 1) that if in fact that two separate conductors were run to a panel, but were of the same phase, you would still have 120 volts, but with more possible current capacity. 2) OTOH, if each of these two conductors (at 120 volts each) were Out of phase with each other, Then the DIFFERENCE between them will equal 240 volts.

I have heard this discussed more than once, especially at the PS Audio site, which would be damned near a reference for me.

Believe in the tooth fairy if you like, but ONE phase of the three 240 volt lines is run to residential property. 120 volts is derived from the Neutral Center tap and each leg of the transformer. A lot of PS Audio is bunk!

 

That's right, @jea48 , it was a large toroidal transformer humming. You answered my query and we discussed what might be causing it before I called the electrician. I'm always appreciative of the help you and others provide. 

Your explanation regarding isolated ground rods confirms what I thought. There have been many electrical threads where the OP has believed that isolating grounds either in the house or in the ground will reduce noise. I know there must be only one common ground but was looking for the final word on ground rods. Many thanks.

I have never seen phase used for anything other than the distinction between single and three phase in the NEC. Which is what we are talking about in reference to someone claiming that there are 2 phases in single phase service.

2 phase power is not used anymore.

For something to be out of phase, there must be at least two identical wave forms that don’t line up. In 3 phase power, 3 wave forms are 120 degrees out of phase. In single phase power, one wave form is split in two, but not out of phase.

@lowrider57 Said:

Understood. We discussed this when you advised me about replacing my meter box and outside line due to corrosion. If you remember, distortion and DC was entering my service panel.

I remember the thread. Harmonic distortion caused by a corroded connection in the meter socket was causing a problem with a piece of audio equipment. Wasn’t it a noisy buzzing, vibrating, power transformer?

 

I think where I’m confused is from comments in threads about using an "independent" ground rod (or 2) from a subpanel or main panel. My take is that these ground rods are not bonded to the main panel. This doesn’t sound kosher. Is there any reason to use multiple ground rods spread out in the backyard? Yes, I know earth doesn’t possess any magical powers.

Independent, dedicated, isolated, ground rods are dangerous. They violate all electrical safety codes.

NEC 250.54 Auxiliary Grounding Electrodes is one of the dumbest code editions ever. All the additional grounding electrodes do is to provide lightning a direct path into a building’s electrical wiring damaging electronic equipment as it goes on its merry way to the electrical service’s main grounding electrode system back to earth. Lightning loves Auxiliary Grounding Electrodes..

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  I believe what I believe, BUT it doesn't change the truth. It almost depends on which expert you ask about one phase or two going to a residential home. My understanding is this, 1) that if in fact that two separate conductors were run to a panel, but were of the same phase, you would still have 120 volts, but with more possible current capacity.  2) OTOH, if each of these two conductors (at 120 volts each) were Out of phase with each other, Then the DIFFERENCE between them will equal 240 volts. 

 I have heard this discussed more than once, especially at the PS Audio site, which would be damned near a reference for me. 

Leg is not synonymous or the same thing as electrical phase. Most residential homes in the US are single phase. One phase of 240V is brought from the transformer and split into 2 x 120V. It’s one wave cycle split in two—2 legs of the same phase.

Three phase is 3 different wave cycles, 120 degrees apart.

The main purpose for a ground connection to earth is for lightning protection. It does absolutely nothing for improving the sound of an audio system. The earth does not possess some magical mystical power that sucks nasties form an audio system.

If only audiophools understood this one thing...

... and adding additional rods may make the system less capable to survive a strike.

The Ott link seem DoA...

BUT, an equipment equipment grounding conductor still must be ran with the feeder conductors and the equipment grounding conductor shall be terminated to the equipment ground bar in the main electrical panel as well connected to the ground bar in the subpanel.

The purpose of an equipment grounding conductor is to provide a low impedance path for ground fault current to return to the source, the utility power transformer, through the service neutral conductor at the electrical service main electrical panel where all equipment grounding conductors are connected to.

@jea48 

Understood. We discussed this when you advised me about replacing my meter box and outside line due to corrosion. If you remember, distortion and DC was entering my service panel.

I think where I'm confused is from comments in threads about using an "independent" ground rod (or 2) from a subpanel or main panel. My take is that these ground rods are not bonded to the main panel. This doesn't sound kosher. Is there any reason to use multiple ground rods spread out in the backyard? Yes, I know earth doesn't possess any magical powers.

 

@lowrider57 said:

I’ve learned about grounding code from forums such as this. But I’ve been wondering why can’t a subpanel have it’s own grounding rod as long as the main panel has a grounding rod? This is unclear to me because the subpanel ground is tied to the main panel grounding block.

Is a grounding rod ever used on a subpanel?

You can add a ground rod to a subpanel connected to the ground bar in the panel, BUT, an equipment equipment grounding conductor still must be ran with the feeder conductors and the equipment grounding conductor shall be terminated to the equipment ground bar in the main electrical panel as well connected to the ground bar in the subpanel.

The purpose of an equipment grounding conductor is to provide a low impedance path for ground fault current to return to the source, the utility power transformer, through the service neutral conductor at the electrical service main electrical panel where all equipment grounding conductors are connected to.

If the feeder equipment grounding conductor was lifted at one end the only path for ground fault current would be the earth driven ground rod for the subpanel... The earth is a poor conductor... The ground faulted circuit, be it a branch circuit fed from the subpanel, or a faulted feeder conductor, there would never be enough current to overload the breaker and cause it to trip open.

The main purpose for a ground connection to earth is for lightning protection. I does absolutely nothing for improving the sound of an audio system. The earth does not possess some magical mystical power that sucks nasties form an audio system

So forget adding an Auxiliary grounding Electrode to a subpanel that is located in the same building structure... Lightning loves them though...

FWIW, in a separate detached building, structure where a subpanel is installed fed from a main panel ,say in a house, then by code an new grounding electrode system shall be established. An equipment grounding conductor ran with the feeder is still required, connected at both ends to the equipment ground bar.

NEC 250.54 Auxiliary Grounding Electrodes.
It is permissible provided the sub panel feeder from the main electrical panel equipment grounding conductor is connected to the equipment ground bar in the main electrical panel as well to the equipment ground bar in the sub panel. The Aux ground rod ground wire is connected to the ground bar in the sub panel.

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Grounding Myths

"Electromagnetic Compatibility Engineering" by Henry Ott

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."

Henry W. Ott

 

Who is Henry Ott?
http://www.hottconsultants.com/bio.html

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There's no advantage to a subpanel, imo, unless perhaps it can be located close to your system and simplify the rest of the install. As for grounding, all grounds must be bonded together at the main panel and only at the main panel to ensure a fault to ground will trip the breaker.

@cleeds , I've learned about grounding code from forums such as this. But I've been wondering why can't a subpanel have it's own grounding rod as long as the main panel has a grounding rod? This is unclear to me because the subpanel ground is tied to the main panel grounding block.

Is a grounding rod ever used on a subpanel?

 

 

 

 

 

 

'Leg' is synonymous w 'phase'

A home 120VAC panel is fed from a center-tapped transformer.

The Neutral, connected to Earth, is the center tap. Each leg of the panel is connected to one output of the transformer, which are out of phase.

The two legs of the panel are out of phase with one another.

@ieales

Unless the OP has a 3-phase system (unlikely), don't you mean "leg"?

If your hifi is on a seperate circuit as above, you are not going to get noise from an appliance on a seperate circuit.

We must have imagined moving the breaker to the other leg curing the noise.

@lowrider57 Yes and the stupid thing is I have a soft start circuit board that I bought (and tested) off of eBay which is residing inside an incomplete Amplifier project that I’m working on. I’m sure if I would have “Jerry rigged” the AC power between it and my BAT Preamp, I still be listening to the eight 6H30 tubes that reside inside the BAT.

Lesson learned (I guess). The internal fuse I’ve never changed or looked at since I bought it 1.5 years ago.

If the fuse is the wrong amperage, that too would explain a lot. When I checked the fuse, I only checked for continuity, not it’s Amp rating. Stupid me :-(

Damn good question though.

No need for a sub panel. All you need to do is use a piggy back breaker in the existing panel, if you happen to be short on space. If enough room, then add a conventional 20 amp breaker and run 12/2 romex to your receptacle of choice. I chose Audioquest’s Edison receptacle. I believe in synergy, and so I also run a AQ Niagara 1200 into that receptacle along with AQ power cords. The sub panel will not make any difference In sound quality. If your hifi is on a seperate circuit as above, you are not going to get noise from an appliance on a seperate circuit. I don’t care what anyone else tells you here, it’s bull. My breaker for my hifi sits right next to a breaker that controls a fridge, no noise on the hifi circuit. You are making it way more complicated and expensive than it has to be. All you need is a 20 amp breaker that matches what you already have in the main panel, and a high quality hospital grade 20 amp receptacle, be it a home depot or Lowes product or an audiophile receptacle such as Audioquest, Furatech, or oyaide. Lastly, a run of 12/2 yellow romex...no need to run 10 gauge...too stiff and hard to work with. You want to get real fancy, add a RFI/EMF receptacle cover plate by Furatech.

Use Romex cable, unless you have a rat problem, then use metal Clad or conduit. This project is quite simple and not expensive. Black to breaker screw, white to neutral buss bar,  ground to ground bus bar. Heck, I did it with the power on., not recommended. It helps that I took electricity in Vocational school. 😁

Great feedback as I had hoped! I will be PM'img a few of you, hopefully soon. One electrician wanted $100 just to give an estimate. Nope. The other two were in the same ballpark, which is like fives times the cost of materials alone. They were in sync as well with what they would do, which is run a line to s small subpanel in the listening room with x number of lines (equal in-phase) to x outlets. The breaker for the subpanel would be at the top of the stack in the main panel, with other breakers moved to the other bus if they have noisy end points like dimmer switches, appliances, etc. i now really want to do this myself because there is nothing complicated about it. Going to take the week to think it through. Thanks again.

I viewed a video of someone wanting "dedicated" circuits installed into his listening room as you are.  I felt a sense that the electrician that was doing the actual work understood the Audiophile's direction and wants.  Find that such electrician.

So many words, so much misinformation🤔

• Romex offers very good magnetic field suppression
• Twisted wire offers very good noise immunity
• Loose wires in conduit is poor and essentially a radiating transformer
• No current should flow in the ground and if it does there is a problem
• Earth Safety must only tie at a single point unless an engineered solution is installed
• A single over capable current circuit is better than two as two will contaminate each other unless pains are taken to ensure otherwise
• Peak current is far below what will trip a 20A breaker for most home systems
• Breakers will run @ 100% forever, 150% of trip value for a long time and close to 1000% for about a second
• A soft start system control can mitigate power on surge. Ditto sequenced power on.
• Musical peaks are not in phase with the line
• Peak current at full breaker rating drops less than 0.2dB across the AC line over about 50 feet
• If you install two circuits be certain they are on the SAME Phase and on the opposite phase to the noisy stuff. You may need to rearrange the panel, depending on the existing layout. High current things like stoves and dryers are low noise while aircon is higher. Dimmers can play havoc.
• Single breakers opposite one another in a panel are one the same phase. Single breakers on the same side and below one another are the opposite phase.
• IF you are capable, significant system wide noise reduction can be effected by paying attention to the line phase in the electronics
• Ensure the Line, Neutral and Earth Safety connections are pristine all the way to the meter

See Microsoft PowerPoint - Indy AES 2012 Seminar w-Notes v1-0.ppt (wordpress.com)

ldandslow

... provider voltage drop +/- up to 10% is allowed and set by your utility provider, not the national electrical code.

Where I live and in most US states electric utilities are regulated by a Board of Public Utilities or similar entity. The board sets standards, not the utility; the NEC has nothing to do with it. Household voltage in the US is typically spec'd at 120VAC ±5 percent, and a utility must conform to the standard. To be clear, it may not be an easy matter to get a utility to provide the service as required, but it can be done.

I am retired with 30+ years in the electrical field. I do not claim to know everything about anything, yet I have answers to all of your questions. Please PM me if you are interested in discussing this further. My background started in residential wiring in the 1980s and retired in the Power generation and transmission field. I also have worked as a hobby doing home theater and 12vdc installations in my free time since I was a young buck at 14 years old. I am hesitant to post in the thread as every big brain will comment, most of which have no clue will want to argue or debate the topic. There is no debating the physics of electricity or proper grounding. Several questions need a yes answer before investing in power supply isolation is discussed. (Type of service entrance, proper grounding being most important in multiple A/C panel installs, bonding, provider voltage drop +/- up to 10% is allowed and set by your utility provider, not the national electrical code.

With Respect,

Grizz

Chad Allen Braden

IBEW Journeyman wireman, power station electrician, certified C & I tech, Electrical shop owner, and so on. I am not an engineer at a desk, I have hands-on knowledge of installation and maintenance. I would still be working if not for being chased by the reaper due to an untreatable nervous system disorder.

@rajugsw , power surge took out your preamp and didn’t trip the surge protector?

 

I ran 10AWG stranded for my Audio only equipment using flexible Armored Conduit (AC) cable that my local electrical supply house provided me. He sold me the stranded 10AWG separately for the AC cable. What a pain in the Ass to fish 3 wires (H,N,GND) through about 70 ft. or so of AC ! But with a Fish Tape, I "got ’er done".

Installed a 20A Breaker at the panel for the Audio Equipment along with a Tripp Lite powerstrip (also 20A) into a PS Audio Receptacle. Ran another circuit 12 AWG AC solid conductor 70ft. run f(also 20A) or just my Computer Equipment, TV, ISP Modem/Router/WiFI box, and any other Computer peripherals.

Strangely, I had a recent power surge which took out my BAT VK50-SE Preamp (sent to their factory already). But NONE of my other equipment was affected. The Preamp was turned off as was everything else except the PS Audio DirectStream DAC and the Bluesound Node 2i.

No power regenerators or conditioning and my AC line is as quiet as a mouse. Maybe I’ll build a Balanced Transformer one day. But for now, I’m happy (until the BAT went down) :-(

My thoughts.

 

First off if you are going to run more than on dedicated circuit make sure they are both on the same side of the 220. Of not it sounds bad. I have seven dedicated circuits in my main listening room. The other things I did was they are all 20. Amp circuit s. I also made sure that every wire was the exact same length. They all have furutech top of the line plugs on them started with industrial grade 20 amp plugs and there was a huge huge difference going to the badboy furutech plugs. At three hundred Canadian a piece it was one of the best HiFi spending I ever did. I also braided the powerline s around eachother to cancel out Rd and EMI. I had open walls so everything was buries in the wall. After that was in placee 5/8 OSB then a layer of 5/8 fire rated drywall much more dense than regular 1/2 in fact it wieghs over twice as much. 

 I should have double layered that but didn't. I stall have very strong and stuff walls. I have the studs and the ceiling all stuff with Rockwood insulation. The back wall is canted one inch in seven and a half feet. And the corners are cut off at and able at the back wall as well. Had the ceiling sprayed with acoustic popcorn ceiling. The wall diffusion and some suction in a very few places. Enjoy and remember when you build something you have to be prepared to realize you made a mistake and start over. You can groove wide thick baseboard to hide wires behind to move power around the room. Also make sure if you run wires down a conduit that the twist around each other some long runs that are parallel are bad. 

 

Regards Tom

I usually like to have @jea48 in these threads because he really knows the NEC and your local code may add more.

On the sub panel issue, I did add a sub panel with a copper buss bar to set up what amounts to a separate subsystem for the hi-fi.* Additional connections notwithstanding, it was a fairly long run from the main panel and adjacent new sub panel up to my room. That was connected via 4 gauge feeder line (I had the electricians install a 10kVA isolation transformer) and the run via 4 gauge eventually terminates in another small sub panel in a room adjacent to the listening room, where 10 gauge Romex was used for multiple dedicated lines to hospital grade Porter Ports from good ol’ Albert (I don’t think he has them anymore). All ground tied back to the main household ufer, as others have mentioned.

They did have to break sheet rock to run the dedicated lines but it wasn’t that big a deal to patch and paint. FWIW, I had Romex in a conduit in a previous set up and it was a disaster- noise on one line (from an air compressor for my tone arm) was transmitted to the system given how the lines were bundled. I think each install presents its own challenges. Even if you are doing your own work in a jurisdiction that permits it, it might pay to get a consult from a solid electrician. I lucked out this time (not the first time I’ve done a dedicated room) and got some commercial electricians who were willing to do residential work as well. Went very smoothly- no issues since this latest installation in 2017.

I have always pulled permits for this stuff and where I am now-- Austin-- is permit crazy. I’ve seen wiring out in West Texas that was absolutely frightening, I figure out in the country, they probably have a guy who does triple duty- Justice of the Peace, funeral director and electrical inspector. :)

______

*This will also help me cut out the hi-fi from the eventual install of a Generac to avoid the problem Fremer said he had with the ATS creating noise on his system even when the generator was not operating. I have no need to play the system when the main power is out, but I'll be able to route to the hi-fi subsystem first, then into the main service panel which will tie to the ATS for the generator system. 

I work for Space X, stuff keeps blowing up. What's your point? Picky! and it's not suppose to blow up? What kind of fun is that?

Party poopers

The way I understood he doest want to or cant go through the wall/walls so running regular NM isn't an option. I would run metal conduit or schedule 40 with THHN since it will be exposed. I could have run mine as well but I got an electrician to do it when I was having other work done. He pulled the permits and saved me the headaches. 

If your panel still has a couple of extra spaces, run 2 dedicated circuits from them with the appropriate breakers to your system.  You don’t need a wire encased in metal. The ground at the panel end goes to the ground buss inside the panel.  The other end goes to the ground on the receptacle in the audio room.  Why make it harder than it needs to be?  I have 2 circuits like this for 23 years with zero noise and zero problems.    A licensed electrician did all the work.