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#164461 - 06/03/07 11:05 PM isolated ground receptacles  
watersparkfalls  Offline
Joined: Mar 2005
Posts: 222
Washington...Not DC
is mc cable ok to use for an isolated ground
circuit? or should i pipe it and pull individual conductors.
keeping in mind that this is going to be for a recording studio and noise elimination is very important....

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#164462 - 06/04/07 12:49 AM Re: isolated ground receptacles [Re: watersparkfalls]  
gfretwell  Offline

Joined: Jul 2004
Posts: 9,142
It is OK if you get "medical" MC with 2 EGCs or the new LiteMC with the bond conductor and an additional green wire for the IG.

Greg Fretwell

#164463 - 06/04/07 01:14 AM Re: isolated ground receptacles [Re: gfretwell]  
watersparkfalls  Offline
Joined: Mar 2005
Posts: 222
Washington...Not DC
after futher reviewing iso ground online...
i've read that installation in plastic boxes nailed to wood frames wouldn't require a forth conductor and that the bare conductor in nm 12-2(home run) ie..dedicated would suffice the iso requirement for device....yet i cant help but wonder if noise couldn't somehow get through nm and cause havoc on my installation. where 12-3 would seem better because wires are twisted and red wire identified green would be insulated and perhaps ensure a better noise free installation? any thoughts? would be cost effective in nm with plastic boxes...but if metal sheilds isolated circuit then perhaps 12-3 mc into metal box would be best route.

#164471 - 06/04/07 10:16 AM Re: isolated ground receptacles [Re: watersparkfalls]  
gfretwell  Offline

Joined: Jul 2004
Posts: 9,142
I bet most of the "noise" is going to actually happern in the studio itself from bad leads and ground loops in that equipment. If the whole system is fed from a single dedicated circuit I am not sure where the noise would come from. Where I can see a problem is where you have interconnected equipment on two different circuits fed from different phases. I have had that in my home MP3 system. I assume I am seeing the added voltage drop across the neutrals or something. Swapping the phase on one end so both ends were on the same phase seemed to fix it.

Greg Fretwell

#164593 - 06/06/07 07:48 PM Re: isolated ground receptacles [Re: gfretwell]  
resqcapt19  Offline
Joined: Nov 2000
Posts: 2,148
There is no evidence that isolated grounds serve any real purpose. The evidence says one of 3 things will happen in about equal makes the problem worse, it makes it better, or it makes no change.


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