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Dedicated line for your system?

98.145.163.72
Posted on August 18, 2014 at 18:00:05
mbnx01
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Location: Eagle, Idaho
Joined: October 22, 2004
 I'm having some general contractors do some work on the house (minor bathroom remodel) and asked them about putting in a dedicated line in my hi-fi room.

Good idea? Anyone have any experience with this or suggestions to offer?

All comments welcome.



'A lie is halfway around the world before the truth gets its boots on'. -Mark Twain

 

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Sure, if practical., posted on August 18, 2014 at 18:11:26
mwhitmore
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Location: San Francisco
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 Ideally, one line for each power amp, one for digital components, one for everything else.

 

There's two schools of thought. , posted on August 18, 2014 at 18:27:05
StephenJK
 1. I'm so glad that I was able to run dedicated circuits to power my stereo. I can see how being able to have unrestricted power makes a huge difference to the sound. Next, I'm going to need new power cords.

2. After power making it to your home from a station hundreds or thousands of miles away - and innumerable transformer stages of dubious quality, what difference could the last few feet possibly make.

I think that pretty much sums it up.

 

The best tweak you can do...., posted on August 18, 2014 at 18:57:05
Rod M
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  Since: March 1, 1999
 If nothing else, you avoid being on your light dimmer or frig line and other junk like computers.

Besides, you need lots of plugs. Install 4 outlet boxes. I have two lines, one for digital and one for analog. In retrospect, I wouldn't mind having more. Since we did it ourselves, the cost of parts isn't much and doesn't take much more time if you're pulling all the wire together.

There are some issues with phases. I can't recall exactly, but I believe the consensus is to have all of one on one the same phase. And surely separate digital from analog.


-Rod

 

RE: Dedicated line for your system? , posted on August 18, 2014 at 19:05:54
fantja
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 A dedicated line is best served for those whom live on a blackout/brownout grid, for example, cities like Los Angeles, NYC, Chicago...etc.

 

RE: There's two schools of thought. , posted on August 18, 2014 at 19:18:46
Tony Lauck
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Posts: 13629
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 I've been conducting some voltage measurements at different outlets in my place. There was quite a drop on one 15 amp circuit when I plugged in a 700 watt load (123 volts down to 115 volts). Then I noticed that the outlet was getting warm. Then I called the electrician....

Many outlets can be wired up by pushing wires into a hole in the back rather than twisting around a screw and then tightening down. This saves a little bit of time. Over years there can be corrosion and the resultant resistance, voltage drop and heat, including potential safety issue. The circuit in question had many outlets daisy-chained together and still has a significant voltage drop. So it seems obvious that that last 50 feet can matter, and it can even matter a lot, possibly even a matter of life and death...

Tony Lauck

"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar

 

RE: There's two schools of thought. , posted on August 18, 2014 at 19:19:36
Tony Lauck
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Posts: 13629
Location: Vermont
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 I've been conducting some voltage measurements at different outlets in my place. There was quite a drop on one 15 amp circuit when I plugged in a 700 watt load (123 volts down to 115 volts). Then I noticed that the outlet was getting warm. Then I called the electrician....

Many outlets can be wired up by pushing wires into a whole in the back rather than twisting around a screw and then tightening down. Over time there can be corrosion and he resultant resistance, voltage drop and heat, including potential safety issue. The circuit in question had many outlets daisy-chained together and still has a significant voltage drop. So it seems obvious that that last 50 feet can matter, and it can even matter a lot, possibly even a matter of life and death...

Tony Lauck

"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar

 

RE: There's two schools of thought. , posted on August 18, 2014 at 19:51:51
commentary
Audiophile

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Location: Bay Area, CA
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 "2. After power making it to your home from a station hundreds or thousands of miles away - and innumerable transformer stages of dubious quality, what difference could the last few feet possibly make."

Then why do they sell so many power line filters for the mains connection in almost everything plugged in?

 

I had it done, posted on August 18, 2014 at 19:59:30
johntoste
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Posts: 459
Location: New England
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 and the system sounds better in every way. I used good Hubble plugs but at some point I may try one of the more exotic options.

To me, the cost/performance ratio is very reasonable. I recommend it.

 

Yes. (mt), posted on August 18, 2014 at 20:01:35
-æ-
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Contributor
  Since: March 1, 1999
 I said empty.

If you aren't quite noticing or accepting what is really going on in the present,
but are responding based on your thoughts or feelings about what ought to be,
then you are apt to collide with what is really going on.

 

"I think that pretty much sums it up." ...., posted on August 18, 2014 at 20:06:02
andyr
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Posts: 12550
Location: Melbourne
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 Then again, you could always do (ie. experiment, to see if it made any difference) rather than just pontificate.

When I changed from just 1 dedicated line for sources to 2 (1 for digital gear, 1 for analogue) that certainly improved my sound.


Regards,

Andy

 

I have two dedicated lines. (nt), posted on August 18, 2014 at 20:20:39
mt10425
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Location: 3 hours west of Chicago
Joined: January 23, 2004



"It's all fun and games until someone doesn't pick up on the sarcasm"

 

RE: There's two schools of thought. , posted on August 18, 2014 at 20:50:02
middleground
 I will go with 2.

 

RE: There's two schools of thought. , posted on August 18, 2014 at 20:51:22
middleground
 So everything being sold has a function and fills a need?

 

RE: There's two schools of thought. , posted on August 18, 2014 at 20:52:49
StephenJK
 No argument there. Those little push pins should never be used, I still use the screws to terminate any device. But the problem you mention could happen on any circuit - one dedicated to audio or otherwise.

 

"I will go with 2."..., posted on August 18, 2014 at 21:00:17
musetap
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  Since: January 28, 2004
 No surprise there!

"Once this was all Black Plasma and Imagination"-Michael McClure



 

Get at least 2..., posted on August 18, 2014 at 21:05:50
mkuller
Audiophile

Posts: 38130
Location: SF Bay Area
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 ...20 amp lines - one for your digital source and one for everything else.

Or more - maybe a separate one for your amp.

 

School #2..., posted on August 18, 2014 at 21:06:57
mkuller
Audiophile

Posts: 38130
Location: SF Bay Area
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 ...are the ones who haven't tried it.

 

Yes., posted on August 18, 2014 at 21:35:26
slapshot
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 I had two dedicated 20 amp lines put in. Not too expensive, and it's good to have a 20 amp line for certain kinds of amplifiers.

 

Yup, posted on August 18, 2014 at 23:25:13
kavakidd
Audiophile

Posts: 20316
Location: Upstate NY
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 -
"Man is the only animal that blushes - or needs to" Mark Twain

 

Actually , posted on August 18, 2014 at 23:25:45
kavakidd
Audiophile

Posts: 20316
Location: Upstate NY
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 a LOT
"Man is the only animal that blushes - or needs to" Mark Twain

 

we put one in the hifi room in the new house, posted on August 19, 2014 at 03:57:27
mhardy6647
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  Since: October 23, 2016
 Given the circumstances, why not? The incremental cost was negligible; "budget dust" as one of my former employers put it :-)

In our case, nothin' fancy -- just top-grade wiring and hospital grade outlets. Our interior decorator actually liked the color when she actually saw them :-)

thoebe
all the best,
mrh

 

RE: "I will go with 2."..., posted on August 19, 2014 at 04:58:25
middleground
 Why thank you!

BTW I had new lines installed to the sound room when a goodly portion of the house was rewired when we bought it five years ago and had a 200 amp service put in.

I feel better about the power going to the system,but to say that any improvement in the sound resulted would be a fallacy.

If Québec has one thing in abundance, it is hydro power. Maybe I live in an audiophile's paradise and I don't even realize it.

There is nothing crazier than those expensive power cables although they seem to reconfirm the power of the placebo effect. Miles and miles of wiring and transformers and such in a utility's system,but the last three feet will create sonic Nirvanah. Yeah, sure...

 

RE: we put one in the hifi room in the new house, posted on August 19, 2014 at 04:59:59
middleground
 "top grade wiring": care to elaborate?

 

Not so simple, posted on August 19, 2014 at 06:16:30
Victor Khomenko
Manufacturer

Posts: 55319
Joined: April 5, 2000
 First question I would ask is - how far is your listening room from your circuit breaker panel?

If very close, say, under 20', then you can do multiple lines, with very little chance of problems.

However, if your distance is, say, 100' - then simply running multiple lines will very likely create whole bunch of problems.

Ideally all your component chassis and signal grounds should be kept at the same potential, or very close to it. Long separate lines will create voltage differences, and the signal interconnects will now carry the equalizing currents - something that is not supposed to happen.

Some people got a very nasty surprise after spending a lot of money on long dedicated lines.

Therefore, if your distance is significant - we are talking about the length of wire here - then do it differently: install a sub-panel in your listening room.

A typical 60A or even a 100A panel is easy to install, and from whence you run short lines to your outlets. This way the ground potential differences will be minimized.

Try to plug all your equipment into the same phase, and allocate the other phase to things like lights, etc.

This approach always gives the best result.


 

Or..., posted on August 19, 2014 at 06:24:58
E-Stat
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 don't have any digital devices plugged into their house wiring, use cordless phones, have routers or wireless access points.

The villain is not the sub station located miles away...

 

RE: Or..., posted on August 19, 2014 at 07:35:38
Jack D II
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Posts: 1535
Location: Hot Springs, AR
Joined: June 17, 2009
 I use 20 amp service through 10 gage wire to a 4 outlet box into a Tripplite unit that protects the equipment against brownouts and the Running "Springs Audio Haley is plugged into the Tripplite and everything is plugged into the Haley except the Quicksilver 88 mono amps. Mike at Quicksilver said not to use a power conditioner but plug the amps directly into the wall. There is a true surge protector circuit breaker (I dont know the brand but it is lit by two green lights and takes up the space usually taken by two ordinary circuit breakers). The dedicated line is further protected by an Environmental Potential 2050 whole house protector. Between the 2050 and the odd circuit breaker the volume has increased by +/- 35% and the system sound has improved tremendously.

 

RE: "I will go with 2."..., posted on August 19, 2014 at 08:09:14
rick_m
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 "If Québec has one thing in abundance, it is hydro power."

Oregon too! Let me tell you, it doesn't help... Bummer. Whatever turns the turbines is fine (power-wise) and in my case it's mostly the Columbia R.

But it's a treacherous journey betwixt generator and Stereo and what comes out at the wall is but a simulacrum of what went in at the dam. Missing in action are the peaks, victims of finite impedances and voracious loads that demand their's off the top.

If have a scope (safely) take a look at your power line, it's probably not a pretty picture. The upshot is a bunch of in-band energy that the power supplies in the gear may not be up to rejecting, it's just about impossible if they don't use chokes and chokes have lost favor because they add quite a bit of cost, size and weight.

Of course at the other end of the system is the noise that your own loads generate and those you can of course ameilorate using thoughtful filtering and topologies.

In the past power-factor problems from rotating machinery were the biggest grid problem, but that was then...

Rick

 

RE: Dedicated line for your system? , posted on August 19, 2014 at 08:51:47
jea48
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Posts: 6770
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 I'm having some general contractors do some work on the house (minor bathroom remodel) and asked them about putting in a dedicated line in my hi-fi room.

You should hire the electrical contractor directly. If you have the GC, General Contractor, take charge of the installation he will tack on anywhere from 10% to 25% on the bill of the electrical contractor for the GC's time and paper pushing.

Good idea? Anyone have any experience with this or suggestions to offer?

Yes. And as others have said have at least 2) 20 amp dedicated branch circuits installed.
If code in your area allows, and installation is feasible, I would recommend 2 runs of NM cable, (Romex is a trade name).

If the wiring must be installed in conduit I would recommend individual runs of MC aluminum armor cable over a single run of conduit with circuits pulled in the conduit.

Make sure the electrician connects the new dedicated branch circuits to 20 amp single pole breakers that are fed from the same Line, leg, in the electrical panel for all audio/video equipment that will be connected together by ICs.

If an electrical permit is pulled the electrician may be required to install AFCI (Arc Fault Circuit Interrupter) breakers. He will also be required to install Tamper Resistant receptacles.

It is important not to use receptacles that use a ferrous steel yoke, back support strap. Also stay away from corrosion resistant nickel plated contact receptacles.

 

RE: Not so simple, posted on August 19, 2014 at 08:59:15
jea48
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 Depends on the manufacture’s design of the equipment.

I have 2) 20 amp dedicated branch of 10-2 with ground NM-B cable that are around 80' each. My audio system is dead quiet.

 

EVERYTHING in life depends, posted on August 19, 2014 at 10:00:46
Victor Khomenko
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Posts: 55319
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 You can get hit by a lightning and live to tell the story.

I am simply talking about good and bad practices. Everyone is free to make his decision. The simple fact is long "dedicated" lines is bad practice.

For a new installation I think it makes sense to follow good practices, which is a sub-panel... and which does not really increase the cost all that much.


 

Not "boutique" wiring, I can tell you that much -- but..., posted on August 19, 2014 at 10:43:42
mhardy6647
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 I'll have to get back to you on the exact type used :-P

I realized after I posted that I should've chosen my words more circumspectly for AA -- I aimply went with the electrician's recommendation of the 'best grade' with which he was familiar; I did NOT go "high end" at all.

I'll ask him (we have him coming in to do a few things soon); if he doesn't remember, I'll pull out the bills and see :-)


all the best,
mrh

 

Really Victor? I didn't know that.., posted on August 19, 2014 at 13:06:18
jea48
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 Like I said it depends on the design of the audio equipment. If the designer was under the impression that earth has some mystical magical power that will suck EMI/RFI noise from his equipment and the designer connects the signal ground to the chassis safety equipment ground then yes long multiple dedicated runs may cause ground loop hum problems. I have seen the same problem where said equipment is plugged into the same duplex receptacle fed from the same branch circuit. What does the manufacture suggest the user do in that case? Use ground cheaters?

I have also seen ground loop hum problems where only one new dedicated branch circuit is installed and the user uses an existing convenience outlet receptacle circuit to power other equipment that is connected together by ICs. This can definitely cause ground loop hum problems.

IF the run is long and the connected load is small make sure the wire is the same gauge and approx the same length. Also as in my case I installed #10 ga wire. Over kill? Maybe but my system is dead quiet.

I would rather have multiple dedicated audio branch circuits of say 40' to 50' long than multiple dedicated audio branch circuits of 10' or less. Not much power supply decoupling going on with 10' or less long branch circuits.
Jim

 

RE: Really Victor? I didn't know that.., posted on August 19, 2014 at 13:26:11
Victor Khomenko
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 Well, you are not correct. As I mentioned before, the equalizing currents, flowing through your interconnects, will be the main source of ground loops. Therefore your goal is to keep the ground potentials between various pieces as close as possible.

It is true that the effect will depend on how the particular pieces of equipment are designed, but the bottom line is - you don't intentionally build a trouble prone system and then hope it will work, you from that perspective, your power amp and your preamp both plugged into the same circuit is the safest solution.

If you put your power amp and your preamp on separate long lines, there will appear a sizable voltage difference between their chassis and neutrals. The best way to avoid it is to install the sub-panel, as I mentioned, and keep the power lines between the components as short as possible.

Nothing will ever guarantee a 100% noise free environment, as some equipment may not be properly designed, but this approach will be the safest.


 

RE: Really Victor? I didn't know that.., posted on August 19, 2014 at 22:15:49
jea48
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Posts: 6770
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 "Well, you are not correct. As I mentioned before, the equalizing currents, flowing through your interconnects, will be the main source of ground loops. Therefore your goal is to keep the ground potentials between various pieces as close as possible."

IF the audio equipment uses double insulated power wiring there is no equipment ground used in the equipment and therefore any difference of potential between safety equipment grounding conductors of multiple branch circuits would not be involved.

IF audio equipment that uses an equipment safety ground does not have its signal ground connected to the chassis with the safety equipment ground then there would be no current path provided through the ICs from one grounded piece of equipment to another grounded piece equipment where its signal ground is also not connected to the chassis.

Beats me why any designer/manufacture of audio equipment connects the signal ground to the safety equipment ground. Again the earth does not possess some magical mystical power that sucks EMI/RFI from audio equipment.



"If you put your power amp and your preamp on separate long lines, there will appear a sizable voltage difference between their chassis and neutrals. The best way to avoid it is to install the sub-panel, as I mentioned, and keep the power lines between the components as short as possible."


First, I have my power amp and preamp connected to the same 20 amp dedicated branch circuit. Digital equipment is plugged into the other 20 amp dedicated circuit. But in my case with my equipment it wouldn't matter.

"If you put your power amp and your preamp on separate long lines, there will appear a sizable voltage difference between their chassis and neutrals."

Please explain further.... "there will appear a sizable voltage difference between their chassis and neutrals."


Grated if the user was using a big poweramp there could be a VD, (voltage drop) at the end of the branch across the connected load.

If the amp is built for the home consumer good chance it will be fitted with a 15 amp plug. Per NEMA and UL standards the FLA draw of the equipment can not exceed 12 amps. Thats a lot of AC power 120V X 12 amps = 1440 watts. Even at a connected load of 12 amps FLA on a branch circuit using #10 wire that is 70' or 80' I doubt there would be any measurable VD. But even if there were please explain how a slight difference of potential from one neutral of a branch circuit to the neutral of another branch circuit could cause a ground loop hum. Remember you are talking about the neutral, the current carrying conductor (The Grounded Conductor) and not the safety (Equipment Grounding Conductor).

Getting back to reality I would bet most guys here,.... with all the load of their audio equipment added together does not exceed 10 amps.
Jim











 

RE: Really Victor? I didn't know that.., posted on August 20, 2014 at 05:40:47
Victor Khomenko
Manufacturer

Posts: 55319
Joined: April 5, 2000
 Simply disconnect the equipment from each other and then measure the AC voltages between their chassis and between their signal grounds, in many cases you will see significant voltages present. Sometimes because the signal ground is, in some way, connected to the safety ground, sometimes due to induced potential, but it is often there.

Putting in the sub-panel pretty much eliminates this.


 

I went with a 200 amp service for audioroom all dedicated outlets, posted on August 20, 2014 at 06:49:41
Kloss
 Each line 20 amp all hospital grade rooms like a vault of silence and the AC adds no noise that I can hear or measure I use no filtration live outside of madison in country have own transformer off 3 phase main line.If you can its not such a large expense compared to audio products. Mine added about 3k to cost of homes construction. I also had another 200 amp service for home all big rooms have 1 -20 amp outlet for system use.

 

RE: Really Victor? I didn't know that.., posted on August 20, 2014 at 10:27:55
jea48
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Posts: 6770
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 Simply disconnect the equipment from each other and then measure the AC voltages between their chassis and between their signal grounds, in many cases you will see significant voltages present. Sometimes because the signal ground is, in some way, connected to the safety ground, sometimes due to induced potential, but it is often there.

Agree.

But it should be said the difference in potentials is not always caused by the branch circuit wiring. Sometimes the potentials are caused because the primary winding of the power transformer of a piece of audio equipment was not checked for the proper AC polarity orientation when it was installed and wired into the circuit of the equipment. Due to coupling capacitance of the primary to the secondary of the transformer there is a very good chance there will be a difference of AC potential, voltage, measured from the signal ground of the reversed AC polarity of a piece of equipment to one that has its AC polarity orientation correct.

Sometimes the proper AC polarity orientation is caused from an improperly wired aftermarket power cord where the hot and neutral conductors are reversed at either the plug or the IEC female connector. Usually the reversal is at the IEC female connector.
Also an improperly wired AC power receptacle can have reversed AC polarity.

Wire and wiring methods used for audio branch circuits.

Quote:

The “Conduit Transformer”
• This finally explains what drives 99% of all ground loops!
• Load current in line and neutral produces opposing magnetic fields
since instantaneous current flow is in opposite directions
• Imperfect cancellation magnetically induces voltage over the
length of the nearby safety ground conductor
• Strongly affected by geometry and proximity of wires
• Highest voltages with randomly positioned wires in conduit
• Lower voltages with uniform geometry of Romex®
• Voltage is directly proportional to load current, wire length, and
rate of change in current or ΔI/Δt
• Mechanism favors high-frequency harmonics of 60 Hz
• For constant current in L and N, induced voltage rises at 6 dB/octave


The “Conduit Transformer”
Wires randomly positioned in conduit
produce the worst possible results!

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

Using the proper wiring materials and method of installation is important. Use NM cable (Romex is a trade name NM cable) or MC Cable with an outer aluminum armor jacket. This is a must for long branch circuit runs.
If using NM cable sharp bends should be avoided. Do not coil up any excess power cabling.

Putting in the sub-panel pretty much eliminates this.
Victor

A sub panel can be beneficial if the user has a place out of sight of the living quarters. There in a mechanical room. If installed in the audio listening room and the user later decides to put his home up for sale how will the appearance of the electrical panel appeal to a potential buyer?

And then there is the added cost of the electrical panel, feeder wiring materials, installation labor costs. Especially if the user only wants or needs 2 dedicated circuits installed.

 

RE: Dedicated line for your system? , posted on August 21, 2014 at 11:53:09
Brian Kheel
Audiophile

Posts: 23
Joined: December 29, 2000
 I largely did as Victor discussed - single long wire from the front of the house to subpanel in rear, where the stereo is located. But separate lines for each amp and one for digital source devices amd preamp. And all equipment on same phase. The other phase was used for lighting and other circuits that I added to the room.

In the main panel, I moved around some circuit breakers so that "dirty stuff" like refrigerators, motors that go off often, fluorescents and digital devices such as PC's were on the phase that the stereo was not on. Can't be perfect here but the more the better. And of course, there's nothing that you can do about motors that run on 220 volts, such as central air.

I also made extensive use of electrical noise filters on the amp outlets and throughout the house.

The power treatment device for the source components shields digital devicess from the preamp and also has excellent electrical noise filtering.

Wiring - 10 AWG metal clad to shield from EMI/RFI.

Test - plugged the power treatment device with the source components and preamp into one of the old, non dedicated lines and then into the dedicated line. As they say, the blacks were blacker. Noticeably so.

 

Some say that powercords represent the first few feet rather than..., posted on August 21, 2014 at 12:08:13
genungo
 ... the last few. In other words, good powercords might help prevent line pollution caused by the gear itself (filters incoming noise as well as outgoing noise).

I'm not sure about the validity of the above idea, but I think I've noticed subtle improvements when changing from cheap powercords to really well built ones like those from PS Audio.

 

Exactly..., posted on August 21, 2014 at 14:13:44
mkuller
Audiophile

Posts: 38130
Location: SF Bay Area
Joined: April 22, 2003
 ...fancy power cords are part of the power conditioning and not the electrical wiring.

 

RE: Dedicated line for your system? , posted on August 21, 2014 at 17:49:01
jea48
Audiophile

Posts: 6770
Joined: January 5, 2005
 But separate lines for each amp and one for digital source devices amd preamp. And all equipment on same phase. The other phase was used for lighting and other circuits that I added to the room.


If the Sub panel is in close proximity of your audio equipment receptacles use care what you feed off the other Line, leg, (phase as you call it) as not to contaminate the power feeding your audio system.

The transformer that feeds your home has what is called a split phase secondary winding. (Assuming your home is fed by 120/240V single phase power)
What that means for your audio equipment, happening at your sub panel, is only the unbalanced load of the 2 hot feeder conductors, returns on the neutral feeder conductor to the source, your main electrical panel.
Example, say all your audio equipment loads combined adds up to a total of 8 amps (average listening level). Say your audio equipment is connected to L1 (Line 1), leg. On L2, the other Line, you have a total connected load also equaling 8 amps.
The 120V connected load on L1 and the 120V connected load on L2 are said to be balanced. Therefore zero amps will return on the neutral feeder conductor to the main electrical panel. The connected loads of L1 are in Series with the connected loads of L2.
Here is another example, your audio equipment total load is 8 amps and L2 has a connected load of 4 amps. In this case 4 amps is the unbalanced load that will return on the sub panel neutral feeder conductor to the main electrical panel. The balanced 4 amps on each Line will be in series.

Incandescent loads connected to L2 would be fine. Motors, CFL, or LEDs, not so good.


In the main panel, I moved around some circuit breakers so that "dirty stuff" like refrigerators, motors that go off often, fluorescents and digital devices such as PC's were on the phase that the stereo was not on. Can't be perfect here but the more the better.


Same thing here you put all the bad things on the other Line, leg, of the panel. Again Only the unbalanced load on the panel will return on the neutral conductor to the power company's utility transformer. The balanced loads are in series with one another.

Another problem if the main electrical panel loads are not somewhat balanced across L1 and L2 that can cause heating problems within the electrical panel busing. Having all the homes 120V induction loads moved to one Line in the panel can cause power quality problems.

 

RE: Really Victor? I didn't know that.., posted on August 25, 2014 at 11:18:51
MylesJ
Audiophile

Posts: 1259
Location: Oregon Coast
Joined: October 25, 2001
 On the advice of a few gurus here and elsewhere this is what I did installing a dedicated circuit.

Using 10ga wiring make a twisted pair of the needed length. Take another 10ga wire for the ground and twist it in the other direction with half the twists per foot of the first pair. I'm out in the woods with no rf problems so I used non-metallic conduit. Some commenters thought a metal conduit might be slightly less dynamic.

 

RE: Really Victor? I didn't know that.., posted on August 25, 2014 at 13:53:41
jea48
Audiophile

Posts: 6770
Joined: January 5, 2005
 Using 10ga wiring make a twisted pair of the needed length. Take another 10ga wire for the ground and twist it in the other direction with half the twists per foot of the first pair.

Yes I have heard that works quite well. Bill Whitlock shows test results where the hot and neutral conductors are twisted together. (See page 35 of PDF Link below. (The twisted together hot and neutral conductors gave the best results.)

I should also mention Sean a member of Agon and AA was recommending twisting the hot and neutral conductors together in posts back in the early 2000s.

As for meeting NEC not sure it would. Not sure if the wires could be pre twisted together before installing in a conduit. The pre twisting together of building wire to then be installed in a conduit would have to be approved by the wire manufacture and then Listed by UL or a recognized testing laboratory. It would also need to be look at as to how it affects conduit fill.

Is it safe to do so for powering audio equipment? Jmo I would not find a problem with it. Connected loads are usually quite low so over heating of conductor insulation due to current flow through the conductors would not be an issue.
Jim

 

RE: Really Victor? I didn't know that.., posted on August 25, 2014 at 18:22:00
BCR
Audiophile

Posts: 2446
Location: connecticut
Joined: April 7, 2009
 Just curious,if the hot and neutral are reversed would not the chassis on the component have voltage going through it and be a hazard?

 

RE: Really Victor? I didn't know that.., posted on August 25, 2014 at 20:10:00
jea48
Audiophile

Posts: 6770
Joined: January 5, 2005
 Just curious,if the hot and neutral are reversed would not the chassis on the component have voltage going through it and be a hazard?

The neutral conductor is a current carrying conductor and is never connected to the metal chassis, case, or frame of a piece of equipment.

The main service neutral conductor is connected to earth and bonded to the service equipment enclosure. The neutral shall not be connected to earth at any point thereafter per NEC Code.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>


http://www.gcaudio.com/resources/howtos/acpolarity.html

 

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