Here's another question........In order to keep the amount of wall penetrations to a minimum (i.e. keep sound 'leakage' to a minimum) I'm going to be using surface mounted outlet boxes.I'm assuming I'll be able to run the romex through a hole in the drywall into the surface-mounted outlet box (so that no romex will show, obviously). Is this legit? Or?Also, in regards to the surface mounted boxes, are my only options the standard, industrial style metal ones? Does anything a bit "smoother" exist?

As long as you're using a UL listed connector for the Romex, you should be fine. As far as exposed outlet boxes, Wiremold makes all sorts of products for just this sort of thing. You'll have to drill out the backplate to accept the connector with a 7/8 hole saw. Here's a link to the product:http://www.wiremoldproducts.com/catalog/model\_V5745.htm?sid=A333B37108FB14D7B8F3289EEE12F831&pid=1228

black taj wrote:Isolated ground receptacles will do nothing at all utilizing a non metallic raceway. Since he is using Romex, IGR's would be a waste.true, but they're useful to know that you have an isolated ground at that outlet, purely from a visual standpoint. I had a mix of standard and isolated grounds, and I used the IGRs to denote which outlet to plug amps into. i guess you could use any other color though. the orange ones look "official".

I know what you're saying, but within a non metallic system, there is no isolation. All the IGR really does is take the self grounding yoke out of the equation. The equipment grounding conductor is still attached to the ground terminal per usual. If you simply wanted to designate which outlets were suitable for amps, then yes, get orange or red or whatever color you want. Remember this: Orange outlets are NOT all isolated grounding types. Isolated grounding outlets will be designated by a green dot on the face of the receptacle. They come in many colors. Hospital grade receptacles will be designated with an orange triangle on the face.I worked at Northwestern's research building and they had a campus wide standard that said ivory for standard outlets, grey for dedicated circuits and red for critical loads. You could probably employ something like that in a studio rather easily.

I got something backwards here. Hospital grade is denoted with a green dot, and isolated ground is denoted with orange triangle.

It doesn't really work like that. An AC circuit simply bounces back and forth between the neutral and the hot. The neutral is what is known as the grounded conductor. Note it is not the grounding conductor. There are systems that actually employ a grounded hot conductor called grounded B phase or corner ground systems. These are rare, and the neutral is the generally accepted term for the grounded conductor.I don't want to seem like I'm hijacking this thread. I'm sure there are people who'd like to know this, I just don't want to get too far afield. I'd start an Ask An Electrician thread, but the thought of all those eager fingers inside panels makes me nervous.

ktone wrote:black taj wrote:All the IGR really does is take the self grounding yoke out of the equation. There is more to it than just that. The advantage is creating a star ground system that is forced by having a home run of romex for each outlet. Even better if that home run terminates at the building steel and main electrical ground or water pipe. This could provide some help with ground loops and induced noise from voltage drops along the neutrals should any recording gear share that neutral with some high current or noisy devices. This is especially helpful with high current stuff like his heaters or incandescent lighting, especially if it is dimmed. BTW dimming with an autotransformer is best. Also, if his requirement is that he provide a minimum amount of heating wattage (thus two heaters) I suggest one 240V high power heater to prevent voltage drops across the neutral. Otherwise he should keep his two heaters on two isolated home run circuits. Even better is to put them on opposing legs of the 240V feed to help keep the load balanced. Of course the thermostats operating at different times would ruin the balancing.What you describe may help mitigate the problem, but the water pipe is still bonded to the neutral at the panel. Part of what I've noticed is that grounds are permitted to be landed on the neutral bus AT THE SERVICE ONLY. Not in sub panels. So if you wanted a simple way to get neutrals (which present circulating currents in the circuit) off your grounds, is to install a ground bar at the panel. This ground bar will then be bonded to your water pipe and your neutral per code. Yes, the ground bar is bonded to the panel and the pipe and should be bonded to steel, it is an indirect connection that may help some.As far as the heaters go, purely resistive loads in and of themselves don't offer much in the way of noise. Inductive loads and loads that have reactance will give your biggest offenders. I had a brief conversation with Steve about EA's grounding system. I was impressed to discover that they employ a chemical ground. Coupled with an isolation transformer, this is probably the only method to get those pesky neutral currents from circulating on your grounds.

black taj wrote:All the IGR really does is take the self grounding yoke out of the equation. There is more to it than just that. The advantage is creating a star ground system that is forced by having a home run of romex for each outlet. Even better if that home run terminates at the building steel and main electrical ground or water pipe. This could provide some help with ground loops and induced noise from voltage drops along the neutrals should any recording gear share that neutral with some high current or noisy devices. This is especially helpful with high current stuff like his heaters or incandescent lighting, especially if it is dimmed. BTW dimming with an autotransformer is best. Also, if his requirement is that he provide a minimum amount of heating wattage (thus two heaters) I suggest one 240V high power heater to prevent voltage drops across the neutral. Otherwise he should keep his two heaters on two isolated home run circuits. Even better is to put them on opposing legs of the 240V feed to help keep the load balanced. Of course the thermostats operating at different times would ruin the balancing.

Give a guy a few wire nuts and he can take down your isolated ground.

black taj wrote:.... with an isolation transformer, this is probably the only method to get those pesky neutral currents from circulating on your grounds.are you talking about power line noise or RFI? Power returns go back on the white wire, right?