Isolated ground in dedicated room/new construction?

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.

terminating with PS audio IG 120v outlets.

@frym

Did you run that by the builder’s electrician? Per NEC you can not install an IG (Isolated Ground) type outlet on a 2 wire with ground NM, (Romex is a trade name), branch circuit. FWIW, An IG outlet would serve no purpose whats so ever connected to the branch circuit wiring. None...

With this set up is there any point in setting up an isolated ground and how do I go about it?

By definition an IG ground wire must be an insulated green color ground wire. The ground wire is connected only to the receptacle outlet IG ground terminal and remains isolated all the way to the EGB, Equipment Ground Bar, in the electrical panel. The IG conductor must be part of the branch circuit cable circuit wiring. (NEC allows the IG ground wire to pass through a sub panel and connect to the Main Electrical Service Equipment Panel, (the sub panel is fed from), and connect to the Grounded Service Entrance Neutral Conductor.)

...Now with that out of the way...

The EGC, (Equipment Grounding Conductor, in the 10/2 with ground will work exactly as the described IG ground wire above provided the EGC is not bonded, connected to a grounded box, or what ever, from the ground terminal on the receptacle outlet to the EGB in the electrical panel. (Which you will have with a true dedicated branch circuit.)

House will have 400 amp service utilizing two 200 amp panels.

Each 200 load center panel will be a sub panel. Approximately how far, distance, is the sub panel, that will feed your three new dedicated branch circuits, from the main electrical service 200 amp breaker?

 

Approximately how far, distance, are the dedicated branch circuits from the audio room wall outlets to the sub panel? ( Measured, up, down, and around).

It is important the electrician does not run the dedicated circuits through the same bored holes through studs or joists. Nor should they be run along side any other branch circuit wiring through bored holes.

After the three dedicated circuits leave the electrical panel as soon as reasonably possible they should be separated from one another by at least 8"- 12" all the way to the wall outlet boxes. Also avoid running the three dedicated circuits parallel to other branch circuit wiring. Especially LED Lighting circuits as well as circuits with lighting dimmers. These circuits are the worse for inducing Harmonic Noise onto the Dedicated Branch Circuits.

 

See page 16. Read pages 31 thru 37

An Overview of Audio System Grounding and Interfacing

 

FWIW...

You might want to consider using solid core 10/2 with insulated green ground. (Solid core #10 conductors, NOT stranded conductors)...

Aluminum armored MC (Metal Clad) cable. (NOT AC Armored Cable.)

I prefer Aluminum Armored MC cable over NM sheathed cable, (Romex is a Trade Name). Especially if the branch circuit runs are long.

Per NEC you still can use a plastic wall box for the outlet for each dedicated circuit.

Why MC over NM?

Cable construction does a better job of controlling any induced voltage from either of the two current carrying conductors onto the EGC. Better than Romex can. Any induced voltage onto an EGC can cause ground loop hum. Especially on long run branch circuit wiring.

The construction of the three conductors are tightly twisted together in a spiral the entire length of the cable. What keeps them tight against one another is the outer aluminum armor.

 

Example Of Aluminum Armored 10/2 MC Cable:

 

@ronboco

Yes, and that includes the branch circuit wiring from the load side of the switch to light fixture(s). When can lights are used in a ceiling it can be a challenge to route the new dedicated branch circuit cable(s) from the parallel running lighting branch circuit wiring. Same for maintaining a distance from the can(s) that house the LED lights.

EDIT:

Also avoid running the three dedicated circuits parallel to other branch circuit wiring.

Should read:

Also avoid running the three dedicated circuits parallel in close proximity to other branch circuit wiring. Especially LED Lighting circuits as well as circuits with lighting dimmers. These circuits are the worse for inducing Harmonic Noise onto the Dedicated Branch Circuits.

.

Would it present as sounding grainy /static? I figured the recordings that have some grain were from the recording.

 

Possibly.

For a test, turn off the circuit that feeds the dimmers and LED lights at the electrical panel. Then listen to your audio system if you can hear any difference.

(Turn off the circuit that feeds the dimmers? If the dimmers have internal back lighting they still spew garbage onto the AC line. Even if the dimmer switch is turned off. If you do hear a difference for the better from your audio system then turn on the breaker at the electrical panel and listen again. You may find with the dimmers turned off with their switch the dimmer does not put out enough noise to affect the sound of you audio system.)

If you do hear a difference for the better then just use a table lamp with an incandescent light bulb for general light in the room for serous listening to music.