Building a "whole room" isotap

[Coytee]

My basement room is in open studs.

Fritzie said something about if I had access to 220, I could do a leg, invert a leg (or something like that) and get an isolated circuit. I guess it would cost several dollars.

My question is basically,

CAN I, and if I can, HOW do I create some dedicated circuits that are isolated?

Am I correct to presume that if I can do that, those circuits will NOT share the same 60hz hum that might otherwise be present?

If the answer to that is yes, then don't I have a perfect opportunity to look into this since my basement is open walls and I can do what I want?

If it's possible to do, then what I'd like to do is add a second panel box for this HT system. I say a second box mainly because my main box only has a couple empty slots in it. A second box will let me mentally and physically, dedicated the HT stuff to a singular target.

So, if that is where I'd like to be, and currently I'm at open walls...

How do I get there?

Rather than get one of those isotap boxes, or build a plug in version, I thought it'd be more cool (more expensive too most likely) to do it at the panel box. This way, I can simply slap in some orange recepticles and know that THOSE are the isolated ones. The lights/fans/pc can be plugged into the regular plugs.

Thoughts? Also, is this likely to be HIGHLY expensive? Meaning is it fair to think it will be several hundred dollars [8-|], or perhaps several thousand? [W]

[DRBILL]

I know it is possible. The Red receptacles in hospital operatives are isolated and completely lifted from ground potential (and are non-interruptable).

Somehow, I am thinking of a very large sum of money.

DRBILL

[Guest " "]

dedicated circuts means that they have individual breakers. dedicated circuts from an electrician's perpspective is not an isolated run.

A no cost solution is simply a matter of putting one amp on one phase of your in-bound 220 (using the 110 - 0 bus) and the other on the opposite phase of your inbound 220 (using the 0 - 110 bus). As you can see, you would be limited to 2 devices, and those devices would still share connectivity with other appliances. Hence the need for a device in between. If you size it correctly, you can have an electrician hardwire the below indicated isolation transformers in a properly constructed metal box, installed to code.

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=122-720

isolation and balanced power are two different things, balanced power often includes isolation, isolation in itself does not cancel out line noise, balanced power does, Also, balanced power that uses autoformers, is not isolated.

so yeah, if you want dedicated circuts that are isolated, you can hardwire isolation transformers in a seperate metal box adjacent to your breaker box. your electrician would know the code issues that need to be addressed during the installation.

[Guest " "]

Here is a photo of an electrical breaker box that includeds a balanced isolated transformer. See the link below for product details.

http://www.equitech.com/products/industrial/wall.html

[Guest " "]

below from the same company is a stand alone balanced transformer that can be mounted in a metal box by your electrical contractor and ran off an adjacent breaker box. The 10 amp is good for about 1200 VA's.

BLOWOUT "TRANSFORMER IN A BOX" (DIFFERENT) - These units are older transformers that were formally used in a precision 10-Amp model that has been discontinued. They were originally designed for professional pro-tools hard disk recording systems that use small self powered monitor speakers and a rack full of effects equipment. In other words they are perfect for diving source electronics in a hi-def audio system as well as a professional recording rig. The transformers are rated at 10 amps, so if they are to be wired into an AC wiring system, we recommend a 10-Amp circuit breaker be installed to drive them. They come mounted in a 16" x 12" x 4" NEMA 1 enclosure that easily bolts to the wall and ideally feeds from a nearby circuit breaker panel. These transformers are just as precisely balanced as any product we make so huge noise attenuation can be expected when used on high-gain "source" electronic components in a high quality audio system. They add a nice clean touch to video quality too. Clearance price - $350 (Only 10 available)

[PrestonTom]

I appreciate your desire to "want to do things right". Certainly doing this at the begining of construction is best. Running a few or several separate dedicated circuits (perhaps including GFI at the breakers) is a good idea. You certainly can explain to the electrician that you are concerned about a good solid ground and that can also be accomodated.

The issue of isolation etc could get very expensive. My experience, and others can argue, is that hum is usually not due to the electrical service running into the room. It is usually due to problems of grounding at the outlets, chassis, inadequate cables (long & high impedance ones), improperly grounded/shielded cables, improperly mixing of balanced and unbalanced equipment or faulty electronics. Even consumer equipment if set up correctly will typically not have any hum. However, there are many ways to screw things up. These can be as simple as mixing ground plugs to different points or connecting both ends of a cable shield to a ground. The list goes on... But these are not usually problems with the electrical service.

Although in a studio, they will do some of the things that you are suggesting regarding 220, isolation, etc. This will give them incredibly low noise floors (if the rest of the set up is also done carefully!!!). But all of this is at a cost and could get quite expensive for a home set up.

I am not aginst the idea, I am just giving a perspective regarding some of the expectations and dollars involved.

Good Luck,

Tom

[Duke Spinner]

I know it is possible. The Red receptacles in hospital operatives are isolated and completely lifted from ground potential (and are non-interruptable).

Somehow, I am thinking of a very large sum of money.

DRBILL

the RED recepticals .......are Emergency Power

[JJkizak]

What's the big deal? Just run your dedicated lines and outlets and use different color receptacles. If your equipment can't handle the power companies ups and downs then get new stuff that does. Most well designed power supplies can handle 90-125 VAC.

JJK

[Duke Spinner]

there is a difference in construction for these recepticals

it's not merely a color

the Orange , for example, has the ground isolated from the mounting strap

it is meant to use a dedicated conductor , say , to building steel, for one,or a ground rod/ ground plane..... ...it is not grounded simply to the device box, and thus tied to the neutral at the Service

[Guest " "]

Duke Spinner

In NY, all recepticals for 110 consist of a red or black 110 lead and a white lead for 0 which is grounded at the fuse box frame (not tied to the receptical box on the receptical box end of the run). The green wire in a receptical end of the run is grounded at the receptical box end of the run.

Orange colored receptical outlets are ethier isolated with UPS backup, isolated with balanced power, or isolated plus ups backup and balanced power.

In the most complex senerio, isolated plus balanced power, we are talking about 60 and 60 on what was red or black and white instead of 110 and 0. There is no longer a 0 reference, and this can not be tied to the service box ground since it is now out of phase 60 (+60 and -60 = 110)

In an isolated senerio there is an isolation transformer of which there could be 2 primary windings wired in series, parallel, and in the case of series wound, whith a ground or a floating ground. On the secondary side, same combo options in terms of series, parallel and grounded or floating ground. What makes this complex is when you also opt for balanced power which now allows 220 (110 - 0 - 110) to be stepped down to 110 (60 - 0 - 60) or 2 phase of 110 to individually be converted to 60 - 0 - 60.

[DRBILL]

DUKE WROTE ---

"the RED recepticals .......are Emergency Power"

And I expect you are right. I was relying on 35 year old memories of when I worked in the engineering department of a large hospital when I was working my way through graduate school. All of the recepticals in our operating suites were isolated (because of the spark and flammable gasses danger) and were also uninterruptable. So you might say they were Emergency Power. They came off that board. They were all red. But they were allways on --not just in emergencies when the main busses went dead. And this wasn't often. The power company had three back-up legs to the hospital that switched automatically.

Back-up was a mighty Delco natural gas fired engine turning a three-phase generator. The change-over wasn't seamless. The engine had to reach full speed and frequency before the change-over relay was allowed to switch --three to five seconds.

I understand that modern stuff doesn't even flicker.

DRBILL

[Duke Spinner]

Orange colored receptical outlets are ethier isolated with UPS backup, isolated with balanced power, or isolated plus ups backup and balanced power.

sorry, S.F..........

"Orange" recepticals ......are simply what I explained....

a receptical, in which the Grounded terminal is not bonded to the device mounting strap, and thefore .. isolated from the common "ground" connection which is Bonded.. with the Neutral at the Service

and they require a separate Grounding Conductor in some fashion.......

they can be wired in many way's

[Duke Spinner]

So you might say they were Emergency Power. They came off that board. They were all red. But they were allways on --not just in emergencies when the main busses went dead.

you are correct ...

the term Emergency Power... means they are fed from a distribution, or load center, that can be fed from an alternate source

obviously, it is impractical to do this with each and every distribution panel....

thus the Red color to identify

[Guest " "]

Duke

We are saying the same thing. Gounding is done upstream, depending on if it is uniterrepted, isolated, balanced, dedicated, etc, the upsteam device uses specific grounding approaches at the upstream end.

tak a look at this link. explains it clearly, nice pictures to.

http://www.hubbell-bryant.com/training_files/ig.asp

[JJkizak]

One hospital explosion proof twist lock120vac plug costs about 75 bucks. Maybe more. The female housing more. This poor guy will have to take out a home equity loan to power up his gear.

JJK

[Guest " "]

JJKIZAK

and the breaker box with a 7.5k VA isolation transformer is about $6000 before labor installation and local permit associated costs.

[Cal Blacksmith]

My local electronics store has (or had the last time I looked) two isolation transformers. They are rated at 220v and 100 amps each. The store wanted $250 each for them. They were taken out of some old computer room and they weigh about 200# each. I am sure I could arange a shipment of one or both if you are willing to pay the freight[]

As to making a statement for what the "electrical code" states, remember that it is different for each city and state.

[Guest " "]

Cal Blacksmith

That must be some electronics store.

I am curious if the secondary windings are center tapped. If you can PM me the name of the shop and their number, I can follow up.

[Cal Blacksmith]

I sure hope they still have them and that I remembered the

specs correctly! It has been a while since I looked at them and the store was "cleaned up" since then[]

I dont have the phone number, but the name of the store is

Electronics Where house

In Riverside Ca. The

transformers were in the annex (a second store they have next door to the

main store, in which they have used items, odd ball items and overstock

obsolete items and the like)

Good luck!

[Guest " "]

Cal Blacksmith

thanks, I'll give them a call.