Possible EM reduction thru grounding?

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Hello folks. I am running a 3/4" em conduit from one side of my garage up the wall interior across the ceiling then down the other wall. The conduit will terminate into plastic double receptical boxes. The conduit will have a ground clamp with 10 gauge single coated wire run to a sub panel which will have an isolated ground termination for all my audio equipment recepticals that that runs to a copper ground plate outside the garage buried >3' deep.

Inside the conduit i will have 2 coax cables for rca ends and some cat 6. Since the ceiling is already insulated and vapour barriered i will have to run the conduit on the warm side which will rest on the resilient channel as it traverses the ceiling.

Question is, will contact between the conduit and resilient channel (which will now be grounded) provide any type of em sheilding from above the garage ceiling,eg radio, satellite? The rc spacing will be 16" on centre. Is this too far apart to block any type of em waves.( I would like it to block something if it can). Or will it pick up interference and inject it into the grounding system causing issues. I am building a sound studio in the garage so every bit of isolation will help. I know nothing of em theory so be gentle please.

Thank you
 
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Ok, so i was hoping that this could turn into an informative thread for anyone else that might do this in the future.
So what i have found is in canada,cell phone service frequencies run between 850-1900 mhz(rural-urban).
Their wavelengths are around 6-12" respectively. Since this is shorter than my current rc spacing i will try to use a metallic mesh with close spacing tied to the regular ground to eliminate these waves from my workspace.
This mesh has a very tight open space so it should take care of most microwave and radio frequencies.
I will use it on the ceiling and north walls as both of those face a cell tower 300 meters away. (Not a big fan of close proximity cell towers,microwave band and all that).
Hopefully someone else has some constructive info to add.? ie: will steel mesh work or is copper the only way to go. Please feel free to chime in.
 
Isolated ground rods in Planet Earth are not permitted by rule, are just asking for equipment damage and Oh yes they are dangerous.
Bonding metal objects (like resilient channel) can be a good idea. It might reduce a few radio frequencies, but it's much too open to act as a good shield.
 
Thanks for the reply Kevin. I have consulted with a few electricians that i work with and they have confirmed that an isolated ground is permitted under Canadian E- code, so i should be good there. It will be a csa approved flat copper ground plate buried at least 3 feet deep according to code.
My sub panel will have a regular #6 ground going back to the main house panel, this is just an isolated ground for the a/v equipment not contacting the regularily grounded panel.
I have split the two legs of my panel, one side for a/v, other side for lights and regular recepticals.
For the a/v side i have
(1) 20 amp double outlet box for mid /high amps and mixers processors.
(1) L5-30 outlet receptical for bass amp.
(1) 20 amp triple outlet box for computer hardware etc.
The 3/4" em conduit housing the two coax cables and cat6 will run from behind my computer to the sound equipment rack on the other side of the garage. The cat 6 is just for future proofing.
The layout of the garage negated me having everything together.
 
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I have consulted with a few electricians that i work with and they have confirmed that an isolated ground is permitted under Canadian E- code,

I don't think so. There must be a misunderstanding somewhere.
All Planet Earth grounding systems (in/to a building) have to be bonded together.
That includes telephone, internet, cable TV and satellite TV grounds.
* * * * * * * * *
Are your sure that they are not talking about Isolated Safety Ground receptacles?
 
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What potential you attach to a Faraday cage will have no effect on its shielding. A good thought experiment is to consider an aircraft at 40,000 feet. It's not "grounded" at all, yet RF principles still apply and work well. Use the safety ground for what it's designed for, and realize that it has absolutely nothing to do with properly designed RF shielding - you can and should have both.
 
In most countries having two earth systems in a single building that are not bonded together, is not allowed unless they are so far apart that you cannot touch both at the same time (minimum distance is set in regulations). Otherwise you may kill people if there is a lightning strike
 
There seems to be confusion or conflation of screening and earthing here.

They are different.

Connecting two different earths to a system does not sound like an idea with a happy conclusion.

If you have equipment that uses one earth for protective ground then adding a second earth for the cabling means you have two earth in the system.

Unless they are at exactly the same potential then you have a problem with your earthing.

It is conceptually similar to cutting a faraday cage in half and earthing the two pieces.

Best case you have is there is little potential difference across your system, and nothing happens. Most likely you will create a big earth loop, and things will hum like a mongrel. Worst case is in fault conditions where you may see damaging or hazardous potentials between what look like safe earth points.

All this stuff with mobile towers hundreds of metres away is I hope a red herring .... if your gear is sensitive to this then you have built a radio receiver, not a stereo. Or it is seriously in need of repair / redesign! (Or you were being subtly humorous!)
 
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In most countries having two earth systems in a single building that are not bonded together, is not allowed unless they are so far apart that you cannot touch both at the same time (minimum distance is set in regulations). Otherwise you may kill people if there is a lightning strike
Most countries don't permit two isolated Planet Earth grounding systems, regardless of the spacing.
 
It looks like there was a misunderstanding of my ideas to the electricians.
I spoke to the lead sparky today and laid it all out. He said it didnt seem to be legal. His first thought was to have the a/v recepticals have an extra ground wire come off the receptical body itself straight back to the panel ground lug. The outlet boxes should have the ground wire from the power line connected to them.
He said he will consult with some inspectors about this and get back to verify. Hopefully he'll get back soon so i can present the proper way here.
Just in case i brought the lastest copy of the ontario electrical code home to study tonight.
Thanks for bringing it up that something wasnt right!
 
Hey guys. So here's what i have learned.
Shield arrangement does not have form a farraday cage, it can be a flat panel dividing the line of sight space between the emitter and the protected object.
Also there is very little difference in level of protection between grounded shield and ungrounded, some applications there is a <10% increase in protection with grounding.
The smaller the mesh the higher the freq protection ,solid covering the broadest range.
All tests i have seen, foil works very well for electromagnetic shielding but not magnetic shielding as it is too thin and saturates quickly.
Also magnetic shielding has to be done with ferro materials.
 
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