Electrical: Shielding

  • Thread starter Thread starter Jack Russell
  • Start date Start date
Jack Russell

Jack Russell

I smell home cookin!
Building a studio here in my basement, slooooooooooooooowwwwwwwllllllllyyyy, week after week...

I'm now to the step of running wire for outlets. My plan is to use one dedicated 2-amp line for all the recording gear, and a separate 14-amp line for the musical gear in the recording room.

My question: are there any special things I need to do to ensure that the wires are sheilded over that of any other typical wire for power?

Don't tell me I need 2-inches of lead plating around the whole damn thing!
 
Jack Russell said:
My plan is to use one dedicated 2-amp line for all the recording gear, and a separate 14-amp line for the musical gear in the recording room.

My question: are there any special things I need to do to ensure that the wires are sheilded over that of any other typical wire for power?

Don't tell me I need 2-inches of lead plating around the whole damn thing!
Click to expand...
You probably need 3 inches of lead plating :D

But, seriously, I've never heard of a 2 amp line or a 14 amp line for household electrical. Are you maybe referring to 12 gauge wire and 14 gauge wire? 12 gauge wire is probably what you need if you are running off a 20 amp circuit breaker, and 14 gauge wire for a 15 amp circuit breaker. You won't need to sheild the wiring, but be sure that your power lines do not run in close proximity to your audio lines to minimize the possibility that you will get 60 Hz noise on your audio lines.

I'm sure there are other pieces of advice others will offer but this is what I have to advise.

Good luck,
Darryl.....
 
Boy, I goofed. I meant 20-amp line and 15-amp line on 12- and 14-gauge wires, respectively. Sorry!

Thanks for the tip.
 
Isn't code 12 ga minimum regardless of the feed? (I think the idea is that wires and loads can get modified and swapped around over time.)
Wayne
 
mixsit said:
Isn't code 12 ga minimum regardless of the feed? (I think the idea is that wires and loads can get modified and swapped around over time.)
Wayne
Click to expand...

I have no idea. My house was built in 2003, in Virginia, and the electrician said 15-amp/14 ga. was standard for most typical outlets, but I told him I'd need a dedicated power line for en eventual studio. He gave me a 20-Amp/12 ga. line for that. At that point I had no idea what an amp was or gauges for that matter.

I asked the 'experts' at Home Depot (hahaha), since I happened to be there buying wire. The guy said 14 ga. was what to use, even in a studio.

I read some other threads related to this in which people are using as many as 5 separate 20-amp lines to their studio gear. Perhaps I need to add one or two?

Does anyone know if adding something like shielding foil around the power line is a good idea? You know, the same stuff you use inside a pot cavity in a guitar.
 
This thread is kind of branching out.

Here's another dilemma: I've always heard that the best thing to do to avoid having any radio interference or noise on your power lines is use one outlet for ALL of your music gear. I take this to mean, your guitar amps, your computer, your board, your effects, your mics...everything. That might end up being too much on one 20-amp line though, since I've read that you can only use up to 20 "devices" on one 20-amp line. (Also, avoid ganging your power lines with your speaker lines, of course.)

So: what about using separate power lines for the recording gear and for the music/performance gear (amps)?
 
OK,

1st - 20 amp - 12 ga wire, 15 amp - 14 ga wire. This meets the NEC.

2nd - all of your gear should be taken off one leg of the service.

Your lighting , HVAC, etc. should be taken off the opposite leg.

3rd - you want to keep your line voltage as far away as you can from your low voltage - if they have to cross you want to do this at a 90 degree angle if possible.

The only time where shielding (of the power cables) should be necessary is when the lines are running parallel to one another in close proximity.

What I generally do is run all of my line voltage up high - and then drop down to where I need to be - all of my low voltage is then run down low and rises up to where it needs to be.

If you can do this you will never actually have to cross lines.

If you really want to do it to avoid problems - then I would suggest that you use hospital grade isolated ground receptacles.

With these you feed your hot legs and box ground through the loop - but each of your receptacles receive their own home run with the ground. This can run back to a seperate grounding panel but eventually has to tie into the main panels earth ground.

This also will help you avoid possible ground loops.


Rod
 
Right on Rod! I was going to wing it' and you did much better. :)
Do you know if the dedicated-receptacle-ground is actually an improvement on a single-feed with a few outlets, or is more aimed at keeping a star-ground simplified?

...since I've read that you can only use up to 20 "devices" on one 20-amp line.
Click to expand...
J. R. It's how much power not how many. It could be fifty wall-warts or 1 1/2 toasters. ;)
Thanks
Wayne
 
Thanks again guys. That was great info!
Unfortunately, some of that went over my head, as I'm not up on electrical terms. (It is a good idea that I have an inspector check what I do, huh? :D )

Anyway, can you elaborate on what are low voltage and high voltage wires?

You mentioned different legs of service. I assume you mean separate fuses/switches in the main fuse box, yes? Or something more separate from the main line?

Thanks,
JR
 
IF you're talking about a typical home studio, you can run the entire thing off one 20 amp circuit easily. I've run one system with a 24 channel mixer, 1/2" 8 track, 3 reverbs, 3 drum modules, 6-7 other sound modules, 3 keyboards, probably close to a dozen other processors, a DAW, couple of LARGE pedal boards, all off the output of a UPS rated at 1400 VA (about 10 amps) - only thing I ran direct was lights and a power amp. Never a hiccup, whole system thru the UPS only pulled around 7 amps at idle, around 8.5 under full load (again, not including the power amp or lights)

Rod's advice won't ever get you in trouble, BTW - he builds major hotels/studios for a living, and is one of the FEW people I rarely argue with :=)

Low voltage is anything you don't hook up to your wall power receptacles; high voltage is everything you DO hook up to your wall power.

"one leg" refers to the standard electrical hookup in homes - your power company provides 240 volts to your electrical box, in the form of two "legs" or wires that measure 240 volts AC (60 hZ) across them; from EITHER of those wires to GROUND or NEUTRAL, you will measure 120 volts. This is because the two "hot" wires are at the same frequency, but 180 degrees OUT OF PHASE - this means that when one wire is +120 volts, (actually more, I won't get into RMS vs. Peak-to-Peak here) the OTHER wire is at -120 volts; so the total across both wires would be 240 volts. From EITHER "leg" to NEUTRAL, you would get 120 volts.

Each plug-in in your house is wired to one or the other "leg", with its neutral being common. NOrmally, a house is wired in a (marginal) attempt to BALANCE the usage from both of these hot "legs" -

For your studio, running two separate circuits is a good idea because you can put all your gear on ONE leg, and all the OTHER stuff (lights, HVAC, refrigerators, etc) on the OTHER leg; this will lessen the amount of NOISE coming in on your power supply.

Unless you have a $300,000 console and five full-frequency surround speakers (about $50,000 EACH) one 20-amp circuit should run all your gear no sweat... Steve
 
Thanks for the clarification, Steve! Appreciate it.
 
You must log in or register to reply here.
Back
Top