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#164461 - 06/03/07 09:05 PM isolated ground receptacles
watersparkfalls Offline
Member

Registered: 03/08/05
Posts: 210
Loc: 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....
thanks
H2o

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#164462 - 06/03/07 10:49 PM Re: isolated ground receptacles [Re: watersparkfalls]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9045
Loc: Estero,Fl,usa
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.
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Greg Fretwell

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#164463 - 06/03/07 11:14 PM Re: isolated ground receptacles [Re: gfretwell]
watersparkfalls Offline
Member

Registered: 03/08/05
Posts: 210
Loc: 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.
thanks,
H2o

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#164471 - 06/04/07 08:16 AM Re: isolated ground receptacles [Re: watersparkfalls]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9045
Loc: Estero,Fl,usa
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.
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#164593 - 06/06/07 05:48 PM Re: isolated ground receptacles [Re: gfretwell]
resqcapt19 Offline
Member

Registered: 11/10/00
Posts: 2209
Loc: IL
There is no evidence that isolated grounds serve any real purpose. The evidence says one of 3 things will happen in about equal proportions...it makes the problem worse, it makes it better, or it makes no change.
Don
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