While awaiting @Jea48’s response (and I agree that he is always superb on these issues), here’s what I did, within code in Austin. recently.
Subpanel off main panel- mainly to give me more room for breakers. I installed a big outdoor isolation transformer, but you don’t have to do that. The output of the transformer was run through 4 gauge feeder wires to another subpanel near the room upstairs. (Without the transformer in the middle, you will probably still want a subpanel with a copper buss bar near the room which I believe is why the heavy gauge wire was used as a feeder). I didn’t use "audiophile" wire from the system subpanel to the outlets- just 10 gauge Romex. I learned from past experience that these have to be spaced apart, because if they are bundled, current or electrical noise on one of these runs can affect the others.
You have to figure out where you want the outlets for the dedicated lines. I didn’t use fancy $400 receptacles, but Albert Porter’s medical grade Hubbell 20 amp receptacles.
I had my electrical contractor pull a permit- they took care of all of that.
I’m sure there are other questions-- issues like which side or phase of the 120 volt legs from a 240 volt system- balancing it for load is normal- the theory is you want the system on the side that doesn’t have the noisy appliances. (This is less of an issue with the isolation transformer).
Grounding- all must come back to the main household ground. JEA can speak to the value or downside of additional grounding rods. You can’t really run a ground that is not in some way connected back (bonded may be the term of art) to the main household ground and electrical service. It is worth having the electrician check your current grounding set up, and how the current service panel is wired, just to make sure what’s already there is in order, so it doesn’t impair what you add. Dedicated lines are not really fully isolated from the main household electrical system, but help- you aren’t suffering current draw or noise from other appliances, lighting, etc. on the same branch. However, in my last system, there were certain low voltage fixtures elsewhere in the house, and certain appliances, that could generate a low level hum or noise despite the dedicated lines. Simple solution- don’t turn those on when you are listening.
I’m sure others, including Jea, can add more, or clarify or correct anything I’ve said. I’m not an electrician, but that’s a short version of what I know. Good luck.
Subpanel off main panel- mainly to give me more room for breakers. I installed a big outdoor isolation transformer, but you don’t have to do that. The output of the transformer was run through 4 gauge feeder wires to another subpanel near the room upstairs. (Without the transformer in the middle, you will probably still want a subpanel with a copper buss bar near the room which I believe is why the heavy gauge wire was used as a feeder). I didn’t use "audiophile" wire from the system subpanel to the outlets- just 10 gauge Romex. I learned from past experience that these have to be spaced apart, because if they are bundled, current or electrical noise on one of these runs can affect the others.
You have to figure out where you want the outlets for the dedicated lines. I didn’t use fancy $400 receptacles, but Albert Porter’s medical grade Hubbell 20 amp receptacles.
I had my electrical contractor pull a permit- they took care of all of that.
I’m sure there are other questions-- issues like which side or phase of the 120 volt legs from a 240 volt system- balancing it for load is normal- the theory is you want the system on the side that doesn’t have the noisy appliances. (This is less of an issue with the isolation transformer).
Grounding- all must come back to the main household ground. JEA can speak to the value or downside of additional grounding rods. You can’t really run a ground that is not in some way connected back (bonded may be the term of art) to the main household ground and electrical service. It is worth having the electrician check your current grounding set up, and how the current service panel is wired, just to make sure what’s already there is in order, so it doesn’t impair what you add. Dedicated lines are not really fully isolated from the main household electrical system, but help- you aren’t suffering current draw or noise from other appliances, lighting, etc. on the same branch. However, in my last system, there were certain low voltage fixtures elsewhere in the house, and certain appliances, that could generate a low level hum or noise despite the dedicated lines. Simple solution- don’t turn those on when you are listening.
I’m sure others, including Jea, can add more, or clarify or correct anything I’ve said. I’m not an electrician, but that’s a short version of what I know. Good luck.
