# New HT Electrical Needs Planning



## puffinak (Apr 3, 2010)

I'm still probably a year or so out before I can start building an HT (still have to buy a house). I'm trying to get better educated on the details of planning and building a dedicated HT.

What tips do you folks have for planning the electrical needs for a new HT?

How many new circuits do you need? 1 15amp for lights, 1 or 2 for a/v equipment. should the project be on its own, or can it share with another say lighting? I really don't know. Look forward to hearing your advice.


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## bpape (Sep 14, 2006)

A lot depends on how big the setup is and how far you want to go.

Probably overkill but I never worry about anything

2 20A in my rack area for processors, DVD, tuners, EQ, xover, Active DA box, IR repeater, misc equipment and have some leftover. PJ is also fed from one of these circuits.

3 20A audio - 1 1500W mono sub amp (not a class D), and 2 400W mono amps

2 15A for non-AV - 1 for utility outlets around the room, 1 for lighting

Everything is star grounded using THHN.

Bryan


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## cbark (May 14, 2010)

Like bpape said above, it depends on how large your set-up is. bpape's power layout would be overkill for pretty much everyone, but as he mentioned, he will not have to worry about anything.

It is a good idea to run seperate circuits for your A/V gear. Star grounding as bpape did is also a very good idea. It doesn't cost much to do it this way, especially if you are doing it yourself. It basically means to run seperate grounds back to the feeder panel where the circuits originate from. The outlets need to be isolated from the conduit runs, or you just negated everything.

Circuits wise, once you draw out your theater layout, you can get a better idea of the loads that need to be powered. For a small theater, you can probably just tap of another circuit in the basement for lighting. Just add up the total lighting current of each fixture, and you will know your load requirements.

A/V gear can be done the same way, add up the total power requirements and you have the number of circuits needed. Most A/V gear does not draw much power, the larger items are some large TVs, subwoofers and power amplifiers. But you usually do not need to go overboard with the number of circuits. If you just have a small system with a receiver, a single circuit will work just fine, but I would run an extra for future use, or if you want to seperate your receiver from everything else. If you have alot of gear, more is better. Some people go to great lengths to seperate the digital, video from the analog equipment, balanced power, different types of line filtering dependant upon use, etc. You can go as far as you would like, but for most people, just some dedicated circuits are fine.

Another note: I have done power quality measurements on some fairly large systems, and one particular example had many power amps with multipule KW worth of power capability, with the system at well beyond reference levels, pulled peak currents of over 50 Amps from the line, but the average currents could be delivered using a single 15A circuit. Two would be better in this example, but the point is that power delivery with power amps is very dynamic. Where as a DVD player that says it draws 100 watts, will probably draw around or a little less than 100 watts.

Hope this helps....


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## puffinak (Apr 3, 2010)

These are great tips guys. Thank you.

Like I said I'm gathering research for planning and building a HT. I don't plan on having something epically large. I'd like to seat probably about 6 (2 rows of 3) something probably about 10x19 (maybe wider) or some similar dimension. I won't know for sure until I find a place.

I'm really sold on the idea of trying to create a space to enable the best audio I can afford. I see posted so often that audio is only as good as the room its in.


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## merc (Oct 3, 2009)

here is my 2C.... for what it is worth.

First, plan on a dedicated circuit for your amp(s)... in many cases, unless they get more than a dedicated 10a circuit, they won't do what you think they will.
Next, do you have a clothes dryer in your home? Is it electric, or gas.... mine was gas and it was very easy and inexpensive to run that unused electric 20a dedicated dryer line to my rack and my amp. You might be able to do the same?

Finally, if you decide to do a new outside box and dedicated lines for your system, Make sure you get a new Whole House Surge System, installed too. (Caps used for emphasis and i am Not yelling)

They can save your fridge, and all other electronics if a lighting bolt goes up the line to your home.... and are well worth the cost if you are doing major upgrades or building a new home, imo.

Let us know what you thing you want to do and we can help further.... :T


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## Wayne A. Pflughaupt (Apr 13, 2006)

puffinak said:


> 1 15amp for lights, 1 or 2 for a/v equipment. should the project be on its own, or can it share with another say lighting? I really don't know. Look forward to hearing your advice.


Like cbark noted, it will largely depend on how complicated your system is.

You’ll need one for the lighting, naturally. A 10A circuit will be sufficient for that.

If you install any wall outlets around the room, I’d put them on a separate circuit as well (not with the lights or the HT gear). Ten amps is probably sufficient for this as well.

For the HT gear, if you have a simple system with an AVR and modestly-powered sub, then a single 20A circuit is sufficient. There’s no need for a separate projector circuit; that plug can be died into the dedicated circuit.

If your system is more complex, I’d break it down a bit and have one circuit for the source electronics, and one for any amplifiers. For a really overkill “big boom” system, I’d add a third circuit dedicated to subwoofer amplifiers.

If you’re going to use a manufactured active subwoofer, make sure to drop an outlet at the location you expect to put it.

Another thing to keep in mind is that all the circuits for equipment should be on the same phase (service leg). Make sure the lighting circuit is on the opposite phase, _especially_ if you’re using dimmers.

Regards,
Wayne


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## merc (Oct 3, 2009)

Wayne A. Pflughaupt said:


> Like cbark noted, it will largely depend on how complicated your system is.
> 
> You’ll need one for the lighting, naturally. A 10A circuit will be sufficient for that.
> 
> ...


If you can afford it... and if you can afford new power components... then you can afford using someone like Wayne...

I have been in this A/V stuff for many years older than my 15 year old son, and I can say before God that Wayne is the best there is and will only charge you what it costs plus a fair expert/labor charge.
Even if you decide to roll the dice, you are best advised by me to follow his advice as best you can and be very, very, very careful as each homes wiring can alter or be hidden for the original electronic routes for profit by the home sub-contractor.

I've had experiences with regard to wiring not being where blueprints said it was and wiring being sub-standard for the circuit once I started looking in my $300k home.

Anyway, Good luck but be careful...


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## Wayne A. Pflughaupt (Apr 13, 2006)

cbark said:


> Star grounding as bpape did is also a very good idea. It doesn't cost much to do it this way, especially if you are doing it yourself. It basically means to run seperate grounds back to the feeder panel where the circuits originate from.


To further qualify, in typical residential construction where Romex is used, _all_ circuits have their own ground wire run back to the service panel. In home theater, if a dedicated circuit has multiple outlets on the circuit, you can’t have a star grounding scheme without adding special wiring. 

For the sake of anyone who doesn’t know, a “star grounding” scheme requires the ground lugs of _all electrical outlets_ to have a dedicated wire run back to the service panel’s ground truss.

The rigid definition of a dedicated circuit permits only a single outlet for the circuit, so a dedicated circuit would (by default) also have a star grounding scheme. However in audio applications, both professional and residential, “dedicated circuits” carries a more generous definition. It typically refers to circuits that are “dedicated to the equipment,” and often multiple outlets are used for the “dedicated” circuits. This automatically negates a star grounding scheme, as it’s typical for all wiring to be “daisy chained” from one outlet to the next.

Star grounding a multi-outlet dedicated HT circuit would require additional wiring to permit the ground of _each outlet_ have a home run wire back to the service panel. IOW, the grounds would not be daisy chained as they typically are. Since Brian mentioned star grounding with THHN, it sounds like this is what he’s done.

Regards,
Wayne


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## bpape (Sep 14, 2006)

Correct. I used THHN to tie back to the box buss from each outlet. The only time I didn't do that was when I had 2 duplexes in a single box so the ground potential difference is trivial.

Bryan


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## merc (Oct 3, 2009)

bpape said:


> Correct. I used THHN to tie back to the box buss from each outlet. The only time I didn't do that was when I had 2 duplexes in a single box so the ground potential difference is trivial.
> 
> Bryan


Hmmm, hope you didn't already do that and hired or consulted Wayne?


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## Wayne A. Pflughaupt (Apr 13, 2006)

merc said:


> Wayne is the best there is and will only charge you what it costs plus a fair expert/labor charge.


Are you confusing me with someone else? I’ve gone out and helped a few folks do some rear-channel speaker wiring, but I don’t recall ever doing any electrical work for anyone. :scratch:

But hey, thanks for the kind words! :T

Regards,
Wayne


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## bpape (Sep 14, 2006)

My cousin is a licensed electrician and did the work.

Guess maybe my wording was wrong above. It was a double gang box with 2 duplexes in it. Outlets were daisy chained inside the box and then THHN run back to the box buss.

Bryan


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## merc (Oct 3, 2009)

Wayne A. Pflughaupt said:


> Are you confusing me with someone else? I’ve gone out and helped a few folks do some rear-channel speaker wiring, but I don’t recall ever doing any electrical work for anyone. :scratch:
> 
> But hey, thanks for the kind words! :T
> 
> ...


Err, well i guess I did misremember if you say so..... and I did the wiring myself for parts only based on your advice..... but I guess I should have suggested that to the new guy too? opps..... just trying to drum up some business for you instead I guess????


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## Wayne A. Pflughaupt (Apr 13, 2006)

> well i guess I did misremember if you say so..... and I did the wiring myself for parts only based on your advice.....


Ah - guess I misunderstood. I only gave you advice – that sounds about right. I thought you were saying I had done the work; that _didn’t_ sound right! 


Regards,
Wayne


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## cbark (May 14, 2010)

Wayne A. Pflughaupt said:


> To further qualify, in typical residential construction where Romex is used, _all_ circuits have their own ground wire run back to the service panel. In home theater, if a dedicated circuit has multiple outlets on the circuit, you can’t have a star grounding scheme without adding special wiring.
> 
> For the sake of anyone who doesn’t know, a “star grounding” scheme requires the ground lugs of _all electrical outlets_ to have a dedicated wire run back to the service panel’s ground truss.
> 
> ...


Good points on the definitions! There can be so many different people that have conflicting ideas about what they consider to be the correct definition. Sometimes when I write a response, I think if I put in too much detail the message will end up being a novel.


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## imbeaujp (Oct 20, 2007)

Hello,

I use 4 20a isolated ground circuits with hopital grade outlets. *I use BX shilded cables*. All on the same phase (different from room lights).

1 - Sub amps (2x RB 1080)
2 - main amp + sorround amp (1x RB 1080 + 1x RB 1075)
3 - Audio equipment (on a RLC-1040)
4 - Computer équipement and projector (on ups)


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