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GROUNDING PLEASE HELP!!!
Old 20th January 2007
  #1
Gear Addict
 

GROUNDING PLEASE HELP!!!

Hi I gonna use a garage for my studio.
I found out that seems is not ground.

Any suggestions?
A friend told me that the ground could be connected to the metal boxes that hold the switches and power outlets...any good way to find out that?


There is any device like a monster Cable/Furman that connecting all your gear there you would not need ground?

Please help would be very welcomed!
Old 20th January 2007
  #2
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nosebleedaudio's Avatar
 

If wired with romex the box will not be grounded.
The best is to run a new 12/2 with ground to the panel.
One circuit will be plenty, unless you have a 40 channel SSL...
Old 20th January 2007
  #3
Gear Addict
 

Hi!! do you mean to the main switch??
Romex? please if you can explain that with more detail..i am not very good with that type of electrical installations!!
Thanks!!!thumbsup
Old 20th January 2007
  #4
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Rick Sutton's Avatar
 

Absolutely hire an electrician to sort this out for you. This isn't something to mess with if you are not familiar with electrical wiring. It isn't "rocket science" but it is potentially deadly/disastrous if you are trying to "solve" something that you don't have the training to deal with.
Old 20th January 2007
  #5
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Jason Poulin's Avatar
 

I'm an electrician,


Judging by your lack of knowledge in the issue prompts me to tell you to get a liscenced electrician to help you out.


Without a ground, if you get a short anywhere, and you're touching it, you'll be the new path to ground and get a shock.

It only takes a few milliamps to kill you.

I can't see it costing too much to run a few cables to your studio outlets and make sure they are grounded.


What you can do, is run a #12 awg from your main panel (which I assume is grounded to either a water line or to a ground driven ground rod) and install it on a 20 amp breaker... We actually used a #10 awg cable for ours. There's no harm in going bigger as long as your cable is rated high enough for your breaker size.

This is the cheapest way to do it if your walls are drywalled. If not, than you can just run the cables in the walls or attic.


From there, we fed the other end of the cable into a junction box (in the studio) that acted as a splitter for all the power outlets in the studio. We fed three Monster 3500's and a few other spare outlets.

If you don't understand any of this, spend the extra dough and get some pro help.



Honestly, it's very important to not mess this up. (fire, electricution)


good luck!



Jason
Old 20th January 2007
  #6
Gear Guru
 
drBill's Avatar
Quote:
Originally Posted by neon View Post
Hi!! do you mean to the main switch??
Romex? please if you can explain that with more detail..i am not very good with that type of electrical installations!!
Thanks!!!thumbsup
OK, based on that, you need at the very least an electrician. Better than that would be a studio consultant to get you going in the right direction. That is way past the scope of a post here.

Many electricians are not really hip on what a recording studio needs (like looping outlets instead of home runs back to the box, running the romex in metal conduit, etc.) and will send you on a path to problems even though they are skilled electricians.

Everything you do in the studio will require electricity. Get it right first or you'll have potential problems from here on out.
Old 21st January 2007
  #7
Gear Addict
 

Thanks guys!!

Yeah I will do it!
Just a question because I may have ground...
When the workers where removing some drywalls I saw a Bulb socket that have 3 wires so I tested 2 , both have power so the other must be the ground.

The I found a ground stick outside he garage with some kind of advise saying something about cable TV ground....then this cable goes to one of the power boxes.

then when I checked a couple of electric outlets and switches in the Garage , I only found 2 cables connected to them.....so that extrictly means they dont have any ground ? o the ground could be connected to the metal box of these electric outlets and switches?

I am asking these because is an old spanish house from the 40s.....so who knows!!

and when I changed one of the electric sockets inside the house they had only 2 cables..(same in the garage).... but I dont know again if there is any ground cable that could be connected to the metal chassis that holds them.....that could make sense???
Is just something somebody told me.

so there is not the need to open the drywalls to connect ground in case I need it?

Many thanks guys!!thumbsup
Old 21st January 2007
  #8
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7 Hz's Avatar
Quote:
Originally Posted by neon View Post
I am asking these because is an old spanish house from the 40s.....so who knows!!
Sorry to tell you this, but you probably need to have it all rewired properly. Maybe shouldn't be that much, but it will cost something.

It also sounds like you should not do it yourself.

Quote:
Originally Posted by neon View Post
potential problems
Shocking problems... stike
Old 21st January 2007
  #9
Gear Addict
 

Quote:
Originally Posted by Jason Poulin View Post
I'm an electrician,


What you can do, is run a #12 awg from your main panel (which I assume is grounded to either a water line or to a ground driven ground rod) and install it on a 20 amp breaker... We actually used a #10 awg cable for ours. There's no harm in going bigger as long as your cable is rated high enough for your breaker size.



Jason
So basicly what are you telling me is to connect the ground to the main box that feed electrivcity to the studio?

I am asking to be very informed because i really want to know the best ways when the electrician comes to don't just say OK and then get a bad job!!

Thanks so much!!!!
Old 21st January 2007
  #10
Gear Maniac
 
4stringerfinger's Avatar
 

You definately need it rewired if it is the original wiring. The insulation on the old wire is likely degraded by now. Hire someone to do it. You may luck out and he may be able to use the old wire to pull in the new wire so, yea, you may not have to mess up the drywall. Definately upgrade. Definately hire someone.
Old 21st January 2007
  #11
Gear Guru
 
drBill's Avatar
Quote:
Originally Posted by neon View Post
So basicly what are you telling me is to connect the ground to the main box that feed electrivcity to the studio?
No! To do it correctly, it's more complicated than that. Call someone who does studio consultation / design and tell them what you need, tell them you don't have much of a budget, and ask them what they would tell your electrician to do.

I suggest the following:

A properly implemented star ground system on your gear AFTER the studio is finished. (This means NOT using the grounds in the wall and doing a ground point that is grounded into an external stake in the ground seperate from the AC ground) As an alternative to this - balanced power (ala Equitech)

Home run wiring from the main breaker box. NO looping from outlet to outlet. (Electricians do not understand this for the most part and think you're crazy, but it will reduce your ground potential.)

All romex run thru the walls in metal conduit that it grounded at the breaker box and NOT grounded at the outlet -= ie: use a plastic box at the outlet. This will help with RFI.

#10 (NOT 12) wire throughout for recepticles.

Seperate circuit for lighting than from outlets.

Possible isolation transformer on the outlets.

See, I told you it gets complicated. And this is just touching on it. You will NEVER regret doing it right for the many years you'll use the studio. Do it wrong and you'll regret it every day.

Cheers,

bp
(yes.....I've been down your path before.......)
Old 21st January 2007
  #12
Gear Addict
 

Thanks DR Bill!!!!
Too bad you are not in FL.

Many thanks!!!thumbsup
Old 21st January 2007
  #13
Gear Guru
 
drBill's Avatar
If you don't have a decent budget for this, can't find some qualified locally and need someone who can consult with you over the phone for a minimal fee, shoot me a PM - I know a guy in TX that can guide you thru the worst of it relatively cheaply.

Bill
Old 21st January 2007
  #14
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Barish's Avatar
I'm an electrician too.

The best earthing is the one that is done locally, so if your garage is far from your main building, then get a separate earthing done.

Which means;

You get a min. 3ft x 3ft copper sheet with a wire extension soldered on, and bury it into the soil right under the basement foundation, or just outside the building, in a hole surrounded by Bentonite or Gem dust, and connect all the grounding circuit in your mains network to the extending wire with a star-connection scheme.

If that can't happen, then you get a copper bar with again a wire soldered/clamped on one end, and bury that one in the soil, and connect the grounding circuit to that one in the same manner.

Ideally the potential difference between the neutral and the earth shouldn't exceed 1V, and the earth resistance shouldn't exceed 2 ohms with a Megger device.

The longer the earth line goes around, the more the resistance and the potential difference between neutral and earth. So the best one is to make sure each building has its own earthing scheme (unless some of those buildings have certain equipment installed in which have to be linked to each other by electrical means, in which case separate earthing may cause inconveniences, but that is not relevant in your case).

Get a qualified electrician and have them sort it out for you.



B.
Old 26th January 2007
  #15
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nosebleedaudio's Avatar
 

If you install an extra ground rod they must must must be bonded together.
NEC section 250. covers grounding
NEC section 647 covers balanced power.
Get a real electrician...
Having a seperate isolated ground thats not electrically connected to the main ground is dangerous and against code.
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