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In the Forum: Audio Discussions
In the Thread: It’s mad, mad, mad... electricity.

Post Subject: "Separate Single Ground"Posted by Paul S on: 2/18/2009

The neutral/ground appears to be one of the most commonly misunderstood aspects of the ordinary AC delivery system.

In a normal US residential system, at the main service panel, there are two power bus-bars, each of which gets 120V, for a typical 240V, single-phase service. There is only ONE bus-bar at the main service panel that goes to ground, and BOTH "neutral" and "ground" wires are ALL connected to this bus, from everywhere served by the main panel, including any "sub" panels.

The typical "Ground" wire in this country is a REDUNDANT function, electrically, meant to get any stray current to ground via a wire instead of via a person or pet, etc..

I have NEVER SEEN a hi-fi system served by "dedicated circuits" where the "hot" came from the main service but the NEUTRAL went to a "dedicated" ground instead of returning to the mains ground bus, also, and it would be a code violation if the neutral did not go back to the mains ground.

Every case of a "dedicated ground" I have seen, including my own, involves only the redundant "ground" wire. The "ground" wire may not be useful for every component, and it can actually introduce noise in some cases. I have gone into why at length, above, on several occasions. In some cases, an additional quiet "dedicated" ground that's just or the hi-fi can help to bleed off stray current, or some components may actually be designed so the additional "ground" becomes necessary for the circuit to function per design.

Paul S

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