Acceptable Level Ground/Earth Noise

gs5556 said:

Connect that ground to where the house ground and lightning ground are connected thereby creating a star ground. This way the voltages across the ground rods will be the same in the event of a lightning strike.

gs5556,

I stand corrected. The lightning electrode system shall be connected, bonded, to the grounding electrode system of the electrical service.

Q. Please explain how I’m supposed to ground a service on a building that has a ground ring used for the lightning protection system grounding electrode?

A. If a lightning protection system is installed on a building/structure, it must be bonded to the building/structure grounding electrode system as per 250.106. The grounding electrode for a lightning protection system must not be used as the required grounding electrode system for the buildings or structures [250.60].

http://ecmweb.com/qampa/code-qa-grounding-lightning-protection-system

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Principles of Grounding of Lightning Protection Systems per NFPA 7803.

Grounding

A. There are several types of lightning grounding, used separately or in combination, as selected by the installation contractor. Ground rods, perimeter (ring) bare wire, radials, plates, and concrete (rebar) encased designs all constitute acceptable earth electrodes. The lightning grounding electrode is a dedicated part of the lightning protection system. No other ground shall be used as a lightning ground (see section 4.13.1.3).

B. Other (non-lightning) systems requiring grounding shall be integrated (bonded or connected) to the lightning ground to form a common ground potential (see section 4.14). This is to protect electrical equipment from voltage rise mismatches where separate grounds are employed. Under lightning attachment conditions, the lightning ground will function independently of any other grounds. Should electrical system grounds not be connected to the lightning ground, the overall lightning protection system will still function as designed.

http://lightningsafety.com/nlsi_lhm/grounding_principles_NFPA780.html

For the US anyway, per NFPA780 as well as NEC 250.106 and 250.60.

If my understanding is correct each grounding electrode system shall have its own grounding electrode/s. The two systems are then connected, bonded, together. I assume by a minimum #6awg copper wire. In other words lightning rods cannot be installed and directly connected to the electrical service grounding electrode system. Is that your understanding as well? 

Jim

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almarg said:

Jim (Jea48), thanks for posting the Henry Ott writeup. I’ve seen that before and I always get a chuckle out of it, especially no. 8. For others who may not be aware, Mr. Ott is one of the world’s leading authorities on grounding and various other aspects of electronic design that often tend to be mysterious even to trained EEs.

Hi Al,

I think Ott hit the nail on the head with #4.

4. To operate with low noise, a circuit or system must be connected to an earth ground. False, because airplanes, satellites, cars and battery powered laptop computers all operate fine without a ground connection. As a mater of fact, an earth ground is more likely to be the cause of noise problem. More electronic system noise problems are resolved by removing (or isolating) a circuit from earth ground that by connecting it to earth ground.

AL,

I agree with your post above about disconnecting all that earth grounding that srafi has added, connected, to his audio system. It does nothing for the SQ of his audio. If anything it adds noise. The only ground he should have connected to his audio system is the safety equipment ground.

srafi said:

I did forget to mention it gets louder when I touch the tone arm so could be something else.

To me that sounds like the tone arm is not grounded to the signal ground of the phono preamp. LOL, I’m almost hesitant to use the word grounded. Some take the word as meaning mother earth ground.

If the TT has a ground wire and srafi has it connected to the chassis of the phono preamp it could be the ground wire connection is open/broken. If that is the case there is a good chance it would be inside the TT. For a simple test he could connect a wire at the phono preamp chassis and then touch the other end of the wire to the tone arm or to the tone arm support tower. If the hum stops he has found his hum/buzz problem.

I would also check the cartridge phono wires to make the connections are good.

Jim

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@srafi,

I was searching for some information on your turntable. I ran across the owner manual and found this note.

2.2

To avoid hum noises it can be necessary to ground the bearing. For that please plug in the provided ground cable into the hole of the screw from the bearing at the bottom of the turntable.

It doesn't say were to connect the other end of the cable/wire. I would think it should connect to the phono preamp chassis ground lug/terminal.

Do you have this ground wire connected to the turntable? If so where do you have the other end connected?

Another question. What is the arm you are using on the table? What material is it made of? 

Clearaudio Performance DC Turntable owners manual.

http://clearaudio.de/_assets/_pdf/manuals/turntables/CA_Performance%20DC_E.pdf

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I did forget to mention it gets louder when I touch the tone arm so could be something else.

Is some level of hum part of an analogue setup or should it be absolutely quite?