Installation of new AC lines......best way to ground to avoid loops and noise

minorl said:

Ground loops are created by potential (voltage) differences between equipment on a closed loop, which will cause current to flow in that closed loop.

We are in agreement there.

IF there is a difference of potential between the equipment grounding conductors of more than one circuit feeding audio and or video equipment, that is connected together by wire interconnects, there will be current flow through the chassis, signal ground, of the interconnect connected equipment .

No different than when a difference of potential exists between the shield on an improperly grounded CATV providers coax cable and the equipment grounding conductor of the branch circuit outlet the audio/video equipment is plugged into.

This guy is a well respected EE.
https://centralindianaaes.files.wordpress.com/2012/09/indy-aes-2012-seminar-w-notes-v1-0.pdf

Jim

Edit:
@ minorl , you can edit your post by clicking onto the sprocket looking symbol below your user name and posted message.

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Follow the electrical code of your local municipal area.

^^ This.
@jsautter

You gotta get with the program and go balanced!


But-

If you are concerned about ground loops, the thing to do is make sure that the equipment you use has competent grounding systems internally. Using your DVM measure from the ground of an RCA input to chassis; if you read less than 1 ohm ground loops are probable if the ground connection of the power cord is connected to the ground connection of the AC receptacle. So measure for continuity between chassis and the ground pin of the power cord.

If its not hooked up, seriously consider sending the gear back to the manufacturer for repair. This is the 21st century- people may have gotten away with that 40 years ago but its not acceptable now and oddly a bit too common in high end audio...


Also check between the ground of the output RCA; that should not be at chassis ground either.


Competent grounding of audio equipment isn’t that hard, despite the crazy amount of nuance that exists in this topic. IOW if your house AC wiring is done to code you **should** not have any problems; if you do its not the fault of the AC wiring.

Competent grounding of audio equipment isn’t that hard, despite the crazy amount of nuance that exists in this topic. IOW if your house AC wiring is done to code you **should** not have any problems; if you do its not the fault of the AC wiring.

The NEC is bare minimum electrical safety code.

From NEC Article 90.1 Purpose:

National Electrical Code 90.1 Purpose:

(A) Practical Safeguarding. The purpose of this Code is the practical safeguarding of persons and property from hazards arising from the use of electricity.

B) Adequacy. This Code contains provisions considered necessary for safety. Compliance therewith and proper maintenance results in an installation that is essentially free from hazard but not necessarily efficient, convenient, or adequate for good service or future expansion of electrical use.


The NEC could care less if a person has ground loop hum problems with their audio system. The NEC’s only concern is the AC power feeding the equipment is electrically safe to protect persons and property from an electrical hazard.


Example The NEC allows multiple branch circuits to be installed in a common conduit. Are the chances of ground loop hum greater using this type wiring method than using individual runs of 2 conductor with ground metallic armor MC cable? Yes, it is. Both type of branch circuit wiring meets the NEC.
Individual runs of NM sheathed cable (Romex) installed correctly is better than using conduit with multiple single conductors pulled loosely, randomly, as is the normal installation method used by licensed electricians.

Please read pages 31 through 36.
https://centralindianaaes.files.wordpress.com/2012/09/indy-aes-2012-seminar-w-notes-v1-0.pdf

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One thing about breakers besides copper ,there are silver, silver tungsten circuit breakers which are better and don’t oxidize like Copper Siemens and one other company make them20 amp.