Author Topic: Dedicated subpanel  (Read 7120 times)

shrinkmore

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Dedicated subpanel
« on: February 11, 2007, 11:02:54 AM »
I have in a previous home and am in the next couple of weeks, installing a subpanel with 6 dedicated lines, one for each component.  In this new installation, I will be using 6 audiophile AC cord lines, hardwiring them into the subpanel, each with a dedicated breaker.  Each line will have an IEC (female component plug) for each component, just like a typical plug-in AC cord.  I am wondering if anyone has a definitive answer to:  1) the gains and losses of such a set-up and 2) the risks and benefits of a dedicated ground for the subpanel, i.e., each ground wire from the AC cords will go to a dedicated copper wire that runs to a dedicated grounding rod.  There is already a grounding rod coming off the main panel.  

Thanks for looking,

Doug

Offline Carlman

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Dedicated subpanel
« Reply #1 on: February 11, 2007, 12:26:17 PM »
I installed a dedicated line but I'm not sure I follow what you're saying about the IEC end of things...

Also, are you saying you're considering a separate ground per line (6 grounds) compared to 1 common ground for the subpanel?

Either way, I have no definitive answer for you... but I would imagine no one does as it would be pretty rare to have a situation where you could compare that.  Hopefully someone that knows a lot about grounding can help with what theoretically should be better, though.

Most importantly, CONGRATS on being the 100th member of AudioNervosa!!!  Welcome!  And thanks for starting the first DIY topic. :)

 :beer:
-Carl
I really enjoy listening to music.

Offline bpape

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Dedicated subpanel
« Reply #2 on: February 11, 2007, 03:08:22 PM »
I think you'd get more benefit to do a couple of other things:

- Get enough spaces to assure that all your audio circuits are on the same 110v leg of the box.

- Use the minimum number of circuits needed (with room for expansion).  The fewer different grounds, the less chance of noise.

- Use THHN for your grounds and star ground everything back to the box, or to a common ground point of approximately equal length and then a good ground back to the box.

- Use a separate and better/deeper ground rod for these circuits.   Cold water pipes aren't the best thing and in many houses, tie to less than optimal, fairly shallow ground rods.  To do it right, think about getting at least a 1/2" rod 8' into the ground.

Bryan
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Anonymous

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Dedicated subpanel
« Reply #3 on: February 11, 2007, 04:51:48 PM »
Thanks Carl and Bryan,

Carl

Re: IEC - I am going to use an audiophile grade AC cord, e.g., without a plug installed, so all I will have is bare wire, going directly into the subpanel circuit breaker, neutral bus, and ground bus.  For example, if you took a Violet, and cut off the plug end, then connected it straight into the panel, without a receptacle or plug, and the other IEC or female end, stays as usual, and goes into the components.  There will be 6 of these.  This eliminates 3 mechanical connections near the components, 1) the romex to the outlet; 2) the plug in the outlet; 3) the ac cord to the male plug.  Saving the cost of all those components as well!  The only question is - will direct hard wiring to the panel have some detrimental effect - I doubt it, and will have 3 meters of high quality power cord in between the panel and the component to work it's conditioning.  
 
Not a separate ground rod per line, but each line will go back by itself to the panel, and from there, will be one line to the grounding rod - see Bryan below.
Being the 100th member, did I win anything? lol   :beer:


Bryan,

Yes, I am aware of all audio circuits being on the same phase - thanks for good advice.

Re: minimum different grounds - see above: each component AC cord ground wire will go directly back to the grounding bus on the subpanel, then one line to the independent ground rod.

I will look up what THHN and "star ground" mean.  Thanks, I've heard of star ground configuration before, but don't know what it means; although I'm not sure these apply give the direct hard-wiring back to the box.  Again, I'll check it out.

While we all want a better/deeper rod :roll:, do you think this could actually draw lightening and surges through the audio equipment - I have no idea?

Thanks again guys,

Doug

Offline bpape

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Dedicated subpanel
« Reply #4 on: February 11, 2007, 06:22:38 PM »
I'm pretty sure that what you're describing is against code pretty much everywhere in the US.  Not a nit-picky thing but a great big no-no.  If you're going to hardwire one end to the panel, the other end needs to also be hard wired or if removable, in a grounded, isolated box and hidden - think about a dishwasher or something like that.  What you're basically trying to do is hardwire one end of an extension cord (albeit an expensive one!)

THHN is basically 1 of the strands in a pc of romex but as a single strand.

To star ground, even though you might have the + and neutral daisy chaned between 2 duplexes, you'd ground using THHN from EACH duplex directly back to the box instead of daisy chaining back through with the ground.

The grounding scheme overall sounds good with the separate ground - as long as you don't hook any video equip to the system that would be grounded to the other water ground.  That's not only dangerous but also almost a sure way to induce a nasty ground loop since your new ground will almost certainly be better than the one provided.

As long as ONLY the audio equipment is on this ground, you should be safer if anything.  The cable, phone, etc will attract more and will run through that ground.  

Bryan
I am serious... and don't call me Shirley

shrinkmore

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Dedicated subpanel
« Reply #5 on: February 25, 2007, 12:00:56 PM »
Well, here's what I decided:

I knew hard wiring was a code violation, and decided because of this, as well as to have the opportunity to swap out power cords, that I would use outlets, and I'm going with Oyaide.  I didn't want to be left holding a power cord without a plug when I might decide to swap out, which would be hard to do with hard-wired stuff.  In any case, from the subpanel, fed by a 6 guage dedicated line, I'll be running 5 dedicated 10 guage solid core lines (Romex) to 5 duplex outlets.  One for each component, other than my two digital components, SACD-1 and Monarch M-24 DAC doubled up on one duplex.  I'm lookin' forward to my Black Sand PC's!!!

Surely do thank you for your help.

Double Ugly

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Dedicated subpanel
« Reply #6 on: February 25, 2007, 12:41:09 PM »
Quote from: "shrinkmore"
I'm lookin' forward to my Black Sand PC's!!!
As well you should!  BSC PCs turned out to be one of the biggest audio-related surprises I've had in quite some time.

Be sure and let us know what you think after you've had them in your system a week or two.

-Jim

Christof

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Re: Dedicated subpanel
« Reply #7 on: March 01, 2007, 09:09:58 AM »
Quote from: "shrinkmore"
I have in a previous home and am in the next couple of weeks, installing a subpanel with 6 dedicated lines, one for each component.  In this new installation, I will be using 6 audiophile AC cord lines, hardwiring them into the subpanel, each with a dedicated breaker.  Each line will have an IEC (female component plug) for each component, just like a typical plug-in AC cord.  I am wondering if anyone has a definitive answer to:  1) the gains and losses of such a set-up and 2) the risks and benefits of a dedicated ground for the subpanel, i.e., each ground wire from the AC cords will go to a dedicated copper wire that runs to a dedicated grounding rod.  There is already a grounding rod coming off the main panel.  

Thanks for looking,

Doug

Is your electrical run in pipe?  I just updated a building and local code requred everything to be run in pipe thus I have a common ground with everything :?  The only thing I could do is have the electrician give me three isolated ground outlets.  I also requested that any circuit which would host anything with a motor or possible dimmer be located on one buss bar and my audio/computer alone on the other buss bar.

c.

shrinkmore

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What a huge difference!!!
« Reply #8 on: March 05, 2007, 10:23:44 PM »
My subpanel is installed and man what a huge difference :D .  I cannot emphasize what anyone without a dedicated subpanel is missing in terms of sonic improvement.  Your system will go to a whole new level, levels above what you currently have.  I realize that before, my components were choking on the power they were receiving, and now, they have plenty.  I have nothing to gain and am not selling anything.  This tweak, albeit, relatively big for a tweak, is so inexpensive compared to anything else that you could do to get such an improvement that it just makes sense.  Give it a try, you will not be sorry.  I will be happy to give detailed specs on the general wiring.  This is my second subpanel that I have installed, and running a separate line and outlet for each component, with 2 digital components sharing an outlet, seems to have made a bigger improvement.

Offline richidoo

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Dedicated subpanel
« Reply #9 on: March 10, 2007, 08:03:37 AM »
Sorry this is late, I am trying to catch up reading nervosa posts. Don't worry I won't reply to every one of them... :wink:

I did a lot of research on grounding recently to make an aerial antenna safe from lightning. I am not an electrician nor an expert, so your information may eclipse mine by a long shot...

As I understand, Bryan is right about code "discrepancies". If you have a 2nd ground rod it must be bonded back to the original main panel ground rod. If an electrician installed the 2nd rod, he should have done it to get his permit signed off. If lightning strikes it will hit only one ground system first, and whichever gets hit first you will have many kV potential across the resistance between the two panels and their separate grounds causing hundreds of amps to flow, frying everything in the path and melting wire insulation in the walls! The biggest thing I learned about grounding was to bond all ground rods together with copper that can handle 10,000A for a few milliseconds. NEC requires this. If your house burned down from a strike and fire inspector saw that 2nd rod with no bond, you would be kinda sad about what the insurance company would say.  :cry: If you sell the house without disclosing non code wiring and it burns down you still pay! I am trying not to sound too serious, but maybe I am not succeeding!

Less important but also codeworthy, if your high end AC power cords go into the wall before connecting to the subpanel, they have to be approved for inwall use, like romex is. Maybe if it is run inside grounded metal conduit  inside the walls you would be OK. I dunno. This is more to insure the insulation can adequately protect the conductors from shorting if wet or nail or overcurrent gets in there. Maybe years after you move away and new owner turns your audio room into a spa with a heated jaccuzzi. haha

If you find that binding grounds together add noise/hum, you could have a loop. Often it is not the power that is looped, but the signal wires. Jensen and others make 1:1 signal transformers to lift ground loops. They are pretty transparent to the signal, IMO.  This won't affect your improved power response, but will cure any ground loops that might popup if you add a grounding bond. I know it is not the audiophile way. The alternative is to unplug everything in a storm and never ever forget.

I have similar positive experience with separate circuit, even though I have only one main panel. A 15A switched outlet shared with a lighting circuit is next to a dedicated 20 amp circuit. Moving the amp's plug from one to the other gives a nice improvement. 20amp circuits will have heavier gage wire inwall, which I think is a lot of the reason for the improvement, 2x more copper in the conductor lowers resistance a lot.

I have always thought that running 12ga romex from breaker to component with IEC connector on the end would be interesting to hear compared to outlet and plug. I still don't understand why the last few feet of wire in a different flavor trumps 50 feet of romex in same circuit, but I accept on faith until I learn. I think plug and outlet and wire ga. are more important to lowering resistance than the already low resistance of any decent wire.

Sorry for the wet towel about the grounding, Doug. Maybe check it out just to be safe! I have some links for parts to bond it yourself if you need it.
Rich

shrinkmore

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No wet towel, just a condem.
« Reply #10 on: March 10, 2007, 08:54:50 AM »
Thanks for a very definitive response.  Despite my initial post, I am staying with code, e.g., have romex runs, outlets etc... and at this point do not have an independent ground rod, but the subpanel is grounded back to the main panel.  I do have the ground rod, and your advice confirms other information I have had, that it has to be grounded back to the main rod.  Thanks also for mention of the Jensen ground loop stopper thingy.  

I want to emphasize again to anyone reading this:  If you do not have a dedicated subpanel with dedicated runs to your components, you are missing the most transformative and moderately priced tweak, and your system is not performing up to it's potential.

Offline Inscrutable

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Dedicated subpanel
« Reply #11 on: March 20, 2007, 04:08:58 PM »
Doug et al,
I too have a separate subpanel upstairs waiting for me to finish the theater and listening room.  My only mistake (so far) is that I should have run a circuit or two from the main panel to handle anything up here with a motor (like the refrigerator and if I use a motorized screen).  I think one of the biggest benefits is getting the noise generated by such things off this panel.   I think I can still remedy that situation pretty easily and run those lines.  You guys think the juice is worth the squeeze?

shrinkmore

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Hey Inscrutable
« Reply #12 on: March 20, 2007, 04:28:42 PM »
You probably don't have to worry about your screen motor, which won't be running a lot, unlike a refrigerator motor.  Nonetheless, anything you don't want on the same circuit can go on the opposite lug or pole of the subpanel.  What is the opposite lug or pole?  Half of all your circuit breakers run off of one of the 2 hot wires (probably red and black) going to the subpanel from the main panel (the other two wires are your neutral [usually white] and ground [usually bare copper]).  Usually, the breakers that are horizontally end to end are on the same lug or pole, and then every other space vertically are on the same lug or pole as these.  By using only one lug or pole for your system, you can separate anything else from it, by using the opposite lug or pole.  In addition, it is important to have your equipment on the same lug or pole, so they are in phase.  The only question is if your subpanel is big enough to accomodate the number of dedicated lines you desire, i.e., it should have twice the number of breaker slots that you want for your system, then the other half can be used for other stuff.  If this isn't clear let me know.  

And yes, the juice is worth the squeeze and for that matter, the squeeze is worth the juice.