How to direct my electrician, please advise...

[hally]

Hi All,
I am really lost when it comes to electrics but after some reading here i'm not so lost. However, i'm under pressure to settle on an electrical plan for my studio build, the electrician starts next monday 23rd March and I'm running out of reading time...
I'm based in Ireland and we run on 220 volts. The studio is 2500 sq feet and attached to a residence (an extention built onto the property in the 80's), currently both studio and residence are electrically fed from one main fuse board which is situated in my main live room. Other rooms are live room 2, vocal booth, machine room and control room.

My Plan so far
1. Move the Main fuse box out of the live room to a waiting room next to it.
2. Run a 2nd fuse box for the studio off the main fuse box.
3. Somehow on the new fuse box, seperate all the lighting, switches, heaters, ventilation, electric shower from all the sockets (outlets) for audio gear?
4. Surface mount all electrical boxes and run high voltage, low voltage and data cable in seperate conduits trying to ensure that the cables don't cross and if so at a perpendicular angle.


Questions...
1. How does the above plan sound, i am aware that its vague but will it make sence to an electrician or am i way off the beam?

2. Do i need to consider grounding?

3. Will I need to upgrade the electrical service (amount of amps) delivered to the property?

4. Do I need to provide any further info, floor plan, photos of fuse box, etc to aid people in giving me advise...

I apologise for my lack of knowlodge around electrics and hope someone can help...

Happy Paddy's Day

Warm regards

hally

[SquarePants]

Hi Hally,
I'm similarly "lost", but have just had my studio wired up...

1. Move the Main fuse box out of the live room to a waiting room next to it.

Might be a good idea, if you have to; but could be expensive!

2. Run a 2nd fuse box for the studio off the main fuse box.

Yes. My electrician called this a "sub-board"...

3. Somehow on the new fuse box, seperate all the lighting, switches, heaters, ventilation, electric shower from all the sockets (outlets) for audio gear?

On the sub-board, you can have separate circuits for studio gear, lights, utilities, ventilation etc. As long as studio gear is separate...

4. Surface mount all electrical boxes and run high voltage, low voltage and data cable in seperate conduits trying to ensure that the cables don't cross and if so at a perpendicular angle.

Good idea. Run high voltage down from the ceiling, and low voltage (audio) at floor level.

And your actual questions

1. How does the above plan sound, i am aware that its vague but will it make sence to an electrician or am i way off the beam?

Sounding ok. Talking it through with the electrician will help, too.

2. Do i need to consider grounding?

Yes! Star grounding. Not sure how it works in Ireland, but... run a separate earth from each outlet back to the main earth. Avoid "daisy-chaining" the earths. Show them this: http://www.saecollege.de/reference_mate ... l.htm#star

3. Will I need to upgrade the electrical service (amount of amps) delivered to the property?

Your electrician can tell you if the extra load is ok...

4. Do I need to provide any further info, floor plan, photos of fuse box, etc to aid people in giving me advise...

A floor plan with all outlets, lights, switches etc. will help your electrician. They can generally work out where the wiring goes.

Hope this helps a bit. Happy Paddy's Day too!
Geoff

[Soundman2020]

Hi Hally,

1. How does the above plan sound, i am aware that its vague but will it make sence to an electrician or am i way off the beam?

Sounds like a good start, to me. Except that I'd call them "distribution panels", not "fuse boxes"!

Make sure that your electrician separates all of your "technical" power circuits from all of your "service" circuits, as much as possible. "Technical" is your studio equipment, and nothing else. "Service" is lights, HVAC, other plugs, etc. Anything that is not part of "the set of boxes that processes audio signals" goes on "service" power, including any plugs in the studio that might be used one day for vacuum cleaners, coffee pots, a refrigerator for your beer, or anything else.

You probably don't have 3-phase power, but if you did then the ideal would be to use one phase exclusively for your technical power, and split the service across the other two. But I digress. It is very important to keep all of your technical power (studio equipment) on its own exclusive set of circuits, and everything else on another set of circuits.

2. Do i need to consider grounding?

Oh yess sir! You absolutely DO need to consider grounding! It is the most important thing you can do in your entire electrical installation!!!!

For your technical power circuits, You need to do something called "star grounding", which means that you have one central point, and ONLY one point, where all of your grounding wires come together. They fan out from there to the individual places that need grounding. So each socket gets its own individual ground wire that runs to this central grounding point. Do NOT allow your electrician to daisy-chain the ground from one wall box to the next! That is a major crime in a sound studio, punishable by forty lashes and keel-hauling. And most certainly just take him outside and shoot him if he tries to do a "loop ground", or a "ring ground", that connects several wall boxes in a circle! (OK, so maybe shooting is a bit overboard, but I'm sure you can come up with a suitable alternative...)

OK, so maybe I'm exaggerating a bit, but you get the idea that this grounding thing is important.

If you would like to avoid having electrical hum, buzz, and sizzle in your mix, then
star grounding is the key, the single most important aspect of your electrical work. Make sure that your electrician understands what it is, and how to do it right.

Star grounding. Tell your electrician that this is really important, and that you will not pay him if he doesn't do it right!

Now, that central point of your star-grounding system needs to actually connect to the physical ground, also called "planet earth". And it needs to have its very own ground, NOT the same ground used by the rest of the building. Your ground should be a couple of long copper rods (at least two, preferably four) sunk deep into the actual physical ground outside your building, about a meter or so apart, and joined together with thick copper wire. The same thick copper wire goes to your central ground point, which is usually a "bus" (a copper or brass bar) inside the distribution panel.

Your electrician should already know how to hammer copper rods into the ground, and how to connect them, and how to do a star grounding system, but double-check, to make sure.

So, you end up with an individual copper ground wire coming form each wall box to the central ground bus in the panel, and a thicker copper wire running from there to the physical ground (the copper rods hammered into the ground). There must be no connection at all between the existing ground in the rest of the building, and your clean technical ground. They are two separate things, and cannot ever meet.

3. Will I need to upgrade the electrical service (amount of amps) delivered to the property?

That depends on three things: A) How much do you have available now, B) how much of that are you using now, C) and how much extra will you be using in your studio. If B+C is greater than A, then you need more power coming in. If that is the case, you might even be able to get a SEPARATE feed for the studio, instead of just increasing the capacity of the existing feed. That would be amazingly good, but it would probably not be amazingly cheap!


- Stuart -

[hally]

Thanks a million for the speedy responces, I'm a lot clearer on what needs to be done.
I have a few more questions before I do my final floor plan which i will post here for your inspection....

Now, that central point of your star-grounding system needs to actually connect to the physical ground, also called "planet earth". And it needs to have its very own ground, NOT the same ground used by the rest of the building. Your ground should be a couple of long copper rods (at least two, preferably four) sunk deep into the actual physical ground outside your building, about a meter or so apart, and joined together with thick copper wire. The same thick copper wire goes to your central ground point, which is usually a "bus" (a copper or brass bar) inside the distribution panel.

1. How long and thick do these copper rods need to be and approx how deep into the ground do they need to go?

2. At the back of the studio is my garden, can i put the rods anywhere, ie. out of sight behind a tree, do they need to be sheltered, etc?

3. How thick, what gauge does the copper wire need to be which connects the rods and runs back to the sub distribution panel... just to clarify,

The same thick copper wire goes to your central ground point, which is usually a "bus" (a copper or brass bar) inside the distribution panel

You are refferring to the new sub distribution panel here?

4.

Make sure that your electrician separates all of your "technical" power circuits from all of your "service" circuits, as much as possible. "Technical" is your studio equipment, and nothing else. "Service" is lights, HVAC, other plugs, etc.

In my machine room I will be running 4 seperate dual core PC's, Pro Tools, Giga Studio, VST's and another Giga Studio respectively. Again just to clarify, do the PC's come under "Technical"?

5.

Run high voltage down from the ceiling, and low voltage (audio) at floor level.

When using this method to run cable is it still neccessary to use conduit, ie. plastic pipe, if so what size pipe would you reccommend and thickness?

I think thats all for now and many thanks for the clear advise

Warm regards
hally

[Soundman2020]

Hey Hally. Glad I can help!

1. How long and thick do these copper rods need to be and approx how deep into the ground do they need to go?

The ones I use for this type of installation are solid copper (not hollow tubes!) about 1.5 m long, and about 1.5 cm in diameter. Bigger is better (but might be harder to work with). In Chile, you can buy them in most electrical supply stores. I would imagine that stores in your area carry something similar. Your electrician should know where to buy them. And you hammer them into the ground completely, the entire length. Nothing sticks up above the ground. You should even sink the top ends a few inches below the surface, in fact, and run your ground conductor underground.

2. At the back of the studio is my garden, can i put the rods anywhere, ie. out of sight behind a tree, do they need to be sheltered, etc?

Anywhere you like! They won't be visible, as you sink them completely into the ground, so you don't need to worry about hiding them or protecting them. It's probably not a good idea to put them too close to a tree, though, as you will probably hit a root as you try to hammer them into the ground. Just find some spot where the earth is reasonably soft, so you won't break your back with the hammering. Maybe a flower garden, or the edge of the lawn, or some place like that. It doesn't really matter where you put them, as long as they are completely buried deep down in the dirt, and have a good contact with Mother Earth.

3. How thick, what gauge does the copper wire need to be which connects the rods and runs back to the sub distribution panel... just to clarify,

As thick as you can afford! Ground conductor gauge is certainly defined by code for your area, but you can go BIGGER than that. They just give you a minimum acceptable. Bigger is safer. Bigger offers less resistance electrically, which is GOOD!. When I install machine rooms for video post houses, we use really thick braided copper cable for grounding the racks, about as thick as the cables that connect your car battery. If you can afford to use cables that thick, then go for it. If not, then see what code says, and double or triple that. You can always run several wires in parallel, if you can't buy really thick braided cable. In a pinch, you could use normal 3-core electrical cord (heavy duty) and use all three cores in parallel. That makes a great ground path.

The point is to minimize resistance, and give all that nasty hum and noise a real easy path out of your studio. Your electrician will probably look at you quizzically, and wonder if you are insane for specifying so much overkill in your grounding, but that's OK. It's your studio, and your hum, so you get to decide how much of it you want to get rid of.

You are refferring to the new sub distribution panel here?

Correct. Depending on how they wire things where you live, the sub-panel should already have a couple of long brass or copper bars in it. One is for your neutral bus, the other is for your grounding bus. The panels we get here in Chile have long pre-drilled, pre-tapped bars with screws in them: So there is a line of holes along one side of the bar for inserting the individual ground wires, and a line of screws along the top for holding them in place, then a lug on the end for connecting the conductor that goes out to the physical ground.

In some wiring systems, the neutral bus and the ground bus are actually tied together in the sub-panel or main panel! That might sound stupid, since one leg of your power is grounded, but it is actually a great idea: safer, and even less chance of hum. If your electrical code and wiring scheme allows that, then get your electrician to do it. He'll just install a thick jumper between the two buses in the sub panel. It might not be possible, depending on how things are wired and what code says, but if you can then do it.

In my machine room I will be running 4 seperate dual core PC's, Pro Tools, Giga Studio, VST's and another Giga Studio respectively. Again just to clarify, do the PC's come under "Technical"?

Yup! If it is part of your audio processing gear in any way, or even connected to it(!), then it is technical. So if you have a printer or monitor connected to one of those computers, the printer or monitor is also on technical power. Ditto if you have the computers networked through a router: the router is also technical. In short, if there is any sort of wire that connects two pieces of equipment, and one of them is technical, then the other is also technical.

The reason for all of this is to prevent ground loops. A ground loop is a situation where there are is a voltage difference at two or more points in your grounding system. If there is a voltage difference, then current flows. This usually happens when there are two or more paths to ground, and each path is at a different potential. So if you have, for example, a preamp plugged into one electrical outlet connected to ground point "A", and your console plugged into another outlet connected to ground point "B", then current will flow through the shield of the mic cable that you use to connect the preamp to the console, and that will cause hum. Or if you have your DAW plugged into your service ground, and your speakers plugged into technical ground, then once again you have a potential for current to flow through the shield conductor of the signal cable that connects the DAW to the speakers, and you'll have hum. Third case: Both your DAW and speakers are on the same ground, but the printer is on service ground: There is a potential ground loop path through the printer data cable to the DAW, and thus to your speakers too.

Just think in terms of: Is there any wire at all that connects your audio equipment to something else? If so, then consider either putting that "something else" on technical power and technical ground if you can, or using an isolation device of some type to separate the signals, such that there is no ground path. There are opto-couplers available for some types of signal, and isolation transformers for others. Infra-red links and radio links are also possible, but those are pretty exotic, expensive, and I doubt that you'll need those!

In any event, the point is to make sure that there is only ONE path to ground for your entire studio, and only ONE ground conductor from each wall box to that central ground bus. This way, when you connect a mic cable from the preamp to the console, both ends are at the exact same ground potential already, so no current flows in the shield conductor, and no hum! That's the object of the exercise: keep all of the grounds at the exact same potential, so that no current flows, and there is no hum.

Believe me, you absolutely do want to do this to eliminate all chances of ground loops and hum. If you don't, then tracing and fixing it later will be a nightmare. I speak from first-hand experience: Trying to identify where hum is coming form in a machine room is really, really hard, and solving it can be really, really expensive.

When using this method to run cable is it still neccessary to use conduit, ie. plastic pipe, if so what size pipe would you reccommend and thickness?

Once again, that depends on your local code. In Chile, conduit is required, but even if it wasn't I would still use it, for several reasons. First. it protects the wiring and cabling, but most important for me, it provides an easy way to replace cables and wires, and to install new ones at some point down the line. If you have conduit, and you need to upgrade a circuit to handle more power, or replace a faulty wire or cable, then its really easy to pull the old wiring out, and use that to pull the new wiring in through the same conduit. if you DON'T have conduit, then you have the very sad task of contemplating making large holes in your US$ 5,000 soundproof studio wall... Install conduit for everything: You'll be glad you did. The extra expense is negligible, and the benefits far outweigh the cost. In fact, I normally run a few extra pieces of empty conduit, especially meant for future expansion. It's really cheap to do during installation, and really expensive to do six months down the line when you realize that you just have to have a ______ (fill in the blank) in your live room, and there is no way to get power or signals to it, since your existing conduits are full....

if so what size pipe would you reccommend and thickness?

I normally use at least 20mm conduit for normal electrical wiring. Code here only requires 10mm, but 20mm makes it a lot easier to pull wiring through, and leaves plenty of space for future expansion. If 20mm would be cramped, then go to 25mm or even 32mm.

And DO NOT USE ELBOWS! Just bend the conduit in nice long gentle curves. No tight corners. Tight corners are a death trap for pulling cables. They should be prohibited on pain of death. You can buy "bending springs" at most electrical supply stores for this very purpose: It's a very long metal spring, maybe 50cm long, that is slightly smaller in diameter than the interior of the conduit. You attach it to a piece of wire (so that you can get it out again after the pipe is bent), and let it slide down inside the conduit until you get it to the place where you need the bend, then you gently warm the conduit (I use a small propane blowtorch on a very low setting, playing it back and forth slowly over the conduit) until the plastic becomes soft: Then you bend the conduit to the shape you want (the spring prevents the walls from collapsing or pinching), hold it in that position for a few seconds while the plastic cools and hardens again, then you use the wire to pull the spring out. Presto! Instant gentle bend! That might not be the way to do it where you live, but it is prety much standard here.

Use the largest conduit (within reason!) that you can afford, and that fits in your wall / floor / ceiling while still leaving space for acoustic treatment. At least 20mm for electrical, and bigger for signal and data. Oversize always!

Don't forget that "conduit" is an open pipe, and sound loves to travel down open pipes. So any conduit that links two rooms in your studio, or that runs from outside your studio to inside it, needs to be plugged somehow at both ends (but not permanently!), and needs to have a couple of bends in it, even when they are not needed to get from "A" to "B". No straight pipe runs: always throw in a few curves.

Hope that helps!


- Stuart -

[hally]

Hi Stuart,
sorry I didn't respond sooner, i was away for a few days... Thanks again for a the great advise, i think you have covered every angle...
I will draw up the electrical floor plan tonight hopefully and a list of jobs in sequence for the electrician...
I am trying to get the electrician to give me a total price for the job, rather than charging a daily rate, he's looking for €200 a day which in our current economic climate here in ireland is a taking the mick...

Anyway keep you updated
regards
hally

[Soundman2020]

Hey Hally. No problem: sometimes responses take a while around here.

200 a day? Ouch! Maybe you could some of the work yourself, like installing the conduit, electrical boxes, and stuff like that, then he'd only have to do the wiring: You could even pull the wiring through the conduit yourself, too, then all he'd have to do is to hook it up. At 200 a day, I'd sure be looking for ways to minimize the number of days down to just one!

- Stuart -

[hally]

Hi Stuart, i think your right, I will try and do as much of the prep work myself and I'll probably check back in with you for 1 or 2 more techniqual questions..
I won't be starting till next week...
warm regards
hally

[Lou]

Hi Hally = Just quickly caught your posts.

Trust me dude - 200 a day is bullshit in any financial climate. He's a spark for God's sake not a Barister!

My bloke was £130.00 a day, plus bits naturally.

I agree with Stuart, once you have a clear idea in your head of how everything will go together, do the 'first fix' yourself, and just get him in to make all final connections. Whatever you do make absolutely certain he's 'part p' / 'part 17' qualified and can issue you with a certificate for the council when he's done!

Hope this helps my friend and good luck.

Kind regards,

Lou.

[hally]

Hi Stuart,
I have 3 three electrical contractors working out a quote for me and all are able to certify the work done...
They all had a few questions which you might be able to help me with...

The studio is part of a resedencial house, its a 2,500 sq' extention build out the back and currently the power to the house come from one main distribution panel. I will be installing a new sub distribution panel for the studio and following your advise all technical" power circuits will be routed to this panel and will be star grounded. I was also going to have all of the "service" circuits" on this new sub distribution panel and seperated form technical" power circuits.
Question
Is there any reason why the "service" circuits" ie. studio lights, panel wall heaters, service sockets for fridge, coffee pot, electric shower, tv, etc, cannot remain on the original Main House Distribution Panel, leaving just the technical" power circuits on the new panel which will be star grounded to your specs

All of the electricians understood very well the star grounding procedure or as they refered to it "earthing".
Is it purely the technical" power circuits that have to be grounded in this way or do all of the circuits need star grounding?

And finally, the copper rods that go into the earth, one electrician mentioned we use alluminium here in ireland, is this a problem and would the same specs, width lenght etc apply?

Look forward to hearing from you and I'm really starting to get my head around this electrical stuff

Thanks hally

[Speedskater]

Nothing wrong with aluminum wire, the US power companies use it all the time. The problem starts when aluminum is connected to other metals! You must use special techniques and components when making connections. And all future modifications must follow these same special techniques and components. In the past lots of US houses burnt-down when the rules were dis-regarded.

[hally]

right so, i will stick to the copper rods to keep it simple and clear, any thoughts on my other questions regarding the curcuit seperation?

Thanks
hally

[Rhino]

Did you come up with an answer to these two questions?

s there any reason why the "service" circuits" ie. studio lights, panel wall heaters, service sockets for fridge, coffee pot, electric shower, tv, etc, cannot remain on the original Main House Distribution Panel, leaving just the technical" power circuits on the new panel which will be star grounded to your specs

Is it purely the technical" power circuits that have to be grounded in this way or do all of the circuits need star grounding?

[Speedskater]

Rhino, I'm a long way from New Zealand and I don't know what wiring methods apply. But I think that the answer is the same in any case.
Keep everything but the A/V equipment on the original house circuits.
Star grounding only applies to the A/V equipment on the new technical circuit.
Only allow the Safety Grounds from the house circuit and the technical circuit to join at the main breaker panel.
All ground rods must connect near the main breaker panel ground rod.