ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals

ECN Shout Chat
Top Posters(30 Days)
Admin 16
Recent Posts
ESA Arc flash course
by TheShockDoctors. 03/24/17 10:15 AM
fuse rejectors
by HotLine1. 03/24/17 07:53 AM
Another Forum Update
by Admin. 03/22/17 03:04 PM
Dining room plugs
by watersparkfalls. 03/21/17 10:31 PM
TRUE POWER
by jraef. 03/21/17 09:13 PM
New in the Gallery:
SE cable question
Popular Topics(Views)
231,369 Are you busy
166,092 Re: Forum
160,560 Need opinion
Who's Online Now
0 registered members (), 59 guests, and 10 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#164461 - 06/04/07 12:05 AM isolated ground receptacles  
watersparkfalls  Offline
Member
Joined: Mar 2005
Posts: 216
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


2017 / 2014 NEC & Related Books and Study Guides

#164462 - 06/04/07 01:49 AM Re: isolated ground receptacles [Re: watersparkfalls]  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,057
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.


Greg Fretwell

#164463 - 06/04/07 02:14 AM Re: isolated ground receptacles [Re: gfretwell]  
watersparkfalls  Offline
Member
Joined: Mar 2005
Posts: 216
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


#164471 - 06/04/07 11:16 AM Re: isolated ground receptacles [Re: watersparkfalls]  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,057
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.


Greg Fretwell

#164593 - 06/06/07 08:48 PM Re: isolated ground receptacles [Re: gfretwell]  
resqcapt19  Offline
Member
Joined: Nov 2000
Posts: 2,148
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


Don(resqcapt19)


Member Spotlight
BEAMEUP
BEAMEUP
WA
Posts: 27
Joined: December 2004
Show All Member Profiles 
Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.012s Queries: 15 (0.003s) Memory: 0.7675 MB (Peak: 0.9084 MB) Zlib enabled. Server Time: 2017-03-25 01:43:57 UTC