Recording Studio -Isolated ground/sub panel

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Old 05-11-17, 08:21 AM
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Recording Studio -Isolated ground/sub panel

I am building a recording studio in my basement. I would like to install a sub panel with an isolated ground, separate from the house. I've never done this kind of work before, but I can change a light fixture and build a computer from scratch. So I'll give it a shot.

The main panel is about 25 feet from where I'd like to mount the sub. The space is large so By code I'm looking at about 33 outlets. Most of them quads.

Every electrician has quoted me 5K or more for this work, looking at the the cost of materials, I figure it's more affordable to do it myself.

So...how does one bury a ground for a sub panel?
 
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Old 05-11-17, 09:03 AM
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Moved to electrical forum.

By code in residential wiring a subpanel must have a ground wire (EGC) back to the main panel.
bury a ground for a sub panel
A ground rod (GEC) is not used for a subpanel in the same structure as the supplying panel. In any event a GEC can not substitute for the required EGC.

EGC: Equipment Grounding Conductor is a low resistant path to trip the breaker if there is a fault to the metal chassis of equipment.

GEC: Ground Electrode Conductor is one or two ground rods to help equalize atmospheric charges. Its resistance is often variable and too great to work reliably as an EGC so therefore can't be used in place of the EGC.

Hang in there maybe the pros have a solution.
 
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Old 05-12-17, 08:59 AM
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An isolated ground is really not meaningful in a residential electrical service, and it creates potential safety and code problems. Don't do it. Use a standard four-wire feeder from the main panel to your subpanel. The sub should not have a separate earth ground, as that belongs only at the main building panel.

The thing you should be concerned with is ensuring your electrical service utilizes single-point grounding. That means the ground-neutral bond, earth ground, antenna mast grounds, and reference/bond ground wires to all other telecom and utilities connect only at the main panel. Arlington Industries actually makes an "intersystem ground bar" specifically for this purpose.
 
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Old 05-12-17, 08:52 PM
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If what you are concerned with is ground loops, don't be. If you do it to code, you won't have any difference in potential to cause them.

However IF you want to continue, you CAN install an isolated ground system, but basically to do so involves running the whole system through metallic conduit, and using special isolated ground receptacles (orange with a green triangle on the face - you're looking at about $500 just for the 33 receptacles). The entire raceway system must be metallic, AND you must run the additional ground. You can NOT run Romex and an extra ground. And in the end, all of the grounds will be landing at the same place anyway and you'll have wasted a ton of money doing it. Not only that, but if you intend to have any kind of computer equipment in the studio, it CAN NOT be attached to the IG system - because the power supplies in most machines induce common mode noise into the system.. So do consumer grade power conditioners and UPS's, and even things like AC powered clocks and fans. So to plug anything with a magnetic transformer or switch-mode power supply into the IG system defeats the entire purpose of it.
 

Last edited by taz420; 05-12-17 at 09:15 PM.
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