Isolated ground in new construction?

Am building a custom house from the ground up with a dedicated listening room. Room will have have 3 dedicated 20 amp home runs for the system using 10 gauge 10/2 romex with ground, terminating with PS audio IG 120v outlets. Romex NM wire with plastic boxes, no metal boxes or conduit. House will have 400 amp service utilizing two 200 amp panels. With this set up is there any point in setting up an isolated ground and how do I go about it? Is it even feasible?

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If you have three 10/2 Romex running from one of your main panel, you will have three dedicated ground going to each of your circuits. That’s all you need. What’s more important is what phase you put them in. Put them in the phase opposite any noisy circuits like appliances and such, and put them at the top of the panel if you have a choice. Also, it may too late now, if you already ran Romex, but running the circuits in MC or pipe would be better for shielding RF and EMI. Good luck on building your new system!


Thanks very much for the info. I suspected as much. Let me talk to the electrician about MC cable for those three runs. Might just stick with Romex/NM.

Yes putting them at same phase and moving connections closest to incoming power and ground pays great dividends.

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Since you are running 3 dedicated 20amp circuits adding the isolated ground might be redundant. Using the 10/2 You will have a ground running from your receptacle directly to your ground bus bar in the panel, in theory a isoground. Also not sure if the psa receptacles are isoground capable. I believe they are based on Hubbell 8300s which are ‘hospital’ grade big beefy dudes but I think they lack the isoground feature.

If you did do it the benefits might be most noticeable on components like your streamer, router, network switch, etc….

Since you’re building new, one thing to consider, if you haven’t already, would be to have quads, 2 receptacles wired parallel are going to offer more versatility especially in the future than just one.

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Here’s a tip:

If your house is wood framed construction, every outlet is already an isolated ground.

Isolated grounds are for commercial buildings where metal studs are used. The metal box (only metal boxes are allowed here) ties the safety ground to the building frame. By running an isolated ground, you only bond your equipment back at the panel, ideally all the way to the main service. That avoids having a noisy ground from all the other building systems tied to the safety ground locally. The bond back at the main service is very low impedance and less noisy.

With wood construction, there is no metal framework. So the standard safety ground in a dedicated circuit is exactly the same as an isolated ground, Remember the isolated ground (if used) and the safety ground must be bonded at some place, preferably the main service.

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