Circuit Panel Capacity?

mufsoman

I'm thinking of adding some dedicated circuits for the HT setup. I currently have most of my equipment plugged in to one outlet on a shared circuit. Never had any issues with it even though the breaker is only 10 amps. However, I'm close to pulling the trigger on another amp, so I think its time.

I know there are formulas/rules of thumb for how many circuits/amps can be run off of one panel, so if I would be going over the limit, I'll pursue a second panel.

This current panel has 31 10 amp breakers and one 30 amp. Can I just added two 20 amp circuits to this existing panel? Thanks

rpf65

Not an electrician, but have a limited working knowledge of electrical codes.

You can add extra circuits as long as you have both a place on the power bar as well as a free lug for the neutral. You don't want to share neutral lugs with another circuit. You can share ground lugs, commonly called piggy backing, but not recommended for neutrals.

There is a rule for adding a second, or more sub-panels, but none for individual breakers in a breaker box that I'm aware of.

GlennDog

That picture implies you have room for 7 more circuits. However, that is not always the case. There should be no problem. In that modern panel shown, there should be just as many spots on the neutral bus bar as there is for grounds on the ground bus bar, (meaning you don't want to share grounds, either.) I'm not an electrician either, but I've been around the block.

Msabot1

Should work ok..that is a modern panel..keep the grounds and neutrals dedicated to their own lugs...just like that was mentioned earlier.

disneyjoe7

Not to derail here but.... 10 amp circuits never seen those before?

mufsoman

DJ7 - I thought it was odd to have all 10 amps circuits too, but apparently thats the way all the homes in our subdivision are wired. The 30 amp circuit is for the AC. The furnace, kitchen appliances, washer/dryer, are all on separate circuits, but obviously 10 amp each. There are a lot of circuits, so the house seems to be pretty well distributed. However, I'm not an electrician....

chumlie

Forgot the English button spammer.

F1nut

There should be no problem. In that modern panel shown, there should be just as many spots on the neutral bus bar as there is for grounds on the ground bus bar, (meaning you don't want to share grounds, either.)

Aren't the ground and neutral bars one and the same with two bars total, one bar per side?

Speedskater

While the Neutral bus bar and the Ground bus bar may be the same thing they often are very different animals. In a sub-panel they must be different.

Speedskater

A 100 Amp 'Circuit Panel' (Panel Board) could have thirty two 20 Amp breakers. So long as the total current at any given time though all 32 breakers sums to less than 100 Amps, you are good.

amulford

You will only need one circuit. I would go with a 15 amp, if you go 20 be sure to run at least 12 Ga wire.

I would avoid two because of a possible ground loop issue. With only one ground you cut down on the possibility somewhat.

you have plenty of space in the panel.

F1nut

Speedskater wrote: »

While the Neutral bus bar and the Ground bus bar may be the same thing they often are very different animals. In a sub-panel they must be different.

So, in some panels they are one and the same and in others they are individual? I can't say I've seen a panel with individual bars, but then again, I haven't seen them all.

mufsoman

I live in the Chicago area, so everything is metal conduit with separately pulled wires. There is no ground wire. Outlets are "grounded" through contact with the metal conduit.

So I will have 2 amps, 2 subs, AVR and the rest of the gear to plug in. I was planning on having one circuit for each amp and a third for all else. Three dedicated circuits total, either 15 or 20 amps each. Alternate recommendations???

pitdogg2

F1nut wrote: »

So, in some panels they are one and the same and in others they are individual? I can't say I've seen a panel with individual bars, but then again, I haven't seen them all.

No I'll clarify.

In a sub panel like say a garage you must separate neutral and grounds IF the sub panel don't have it's own ground rod.
Which means you have not tied the two together at the panel. There is a screw that ties both together you do not use that screw that way they are separate

From what I was told by my electrician was that what COULD happen IF I did tie them together the ground at the garage COULD become the house ground going through too small of wire..ie PROBLEMS different ground potential's

If the panel has its own ground rod they can be together as both go to the same as you are NOT using the house ground

In my home panel ground and neutral are both connected to the same depending on placement L/R side of the panel

For my garage project I had to buy an individual ground bar. That is why you have not seen one Jesse

nspindel

Speedskater wrote: »

While the Neutral bus bar and the Ground bus bar may be the same thing they often are very different animals. In a sub-panel they must be different.

The man speaks the truth. When I installed a subpanel it was definitely code that the neutral and the ground had to be different.

dkg999

I would check your ground at the end of each circuit. I rewired a house that used the metal conduit for the ground, and with corrosion on each of the connections, most of the circuits had problems with grounding.

pitdogg2

dkg999 wrote: »

I would check your ground at the end of each circuit. I rewired a house that used the metal conduit for the ground, and with corrosion on each of the connections, most of the circuits had problems with grounding.

You will have that with steel.

Msabot1

nspindel wrote: »

The man speaks the truth. When I installed a subpanel it was definitely code that the neutral and the ground had to be different.

Ground connections and neutral connections are two different animals in a breaker box my friend...they are not one in the same!

Speedskater

mufsoman wrote: »

I live in the Chicago area, so everything is metal conduit with separately pulled wires. There is no ground wire. Outlets are "grounded" through contact with the metal conduit.
[..............................]

Yes, circuits are often grounded (EGC) using metal conduit (or EMT). This metal conduit will carry much more fault current than a wire. But it is often said that conduit can have long term problems from damage and bad connections.

leftwinger57

Before I would say yea go ahead and do it. I would first see what the breaker box is rated for and then what load your carrying now. Don't assume because you have a bunch of extra knock outs that you can just arbitrarily add circuits as you please. Yes 20amp breakers should work.If only using the new lines for your audio gear and nothing heavy like a generator or freezer. I certainly would ask a lineman or an electrician can this be done to be on the safe side. As far as I saw everyone here admitted they were not electricians and certainly can't know codes of every state.My complex is well over 50 years old has 15 amp breakers and used aluminum cable and metal boxes. I don't think Romex was even invented yet. Good luck on your project....

F1nut

pitdogg2 wrote: »

In my home panel ground and neutral are both connected to the same depending on placement L/R side of the panel

Right, that's what I was saying. Not sure where all this sub-panel talk came from, the OP never brought that up.

Ground connections and neutral connections are two different animals in a breaker box my friend...they are not one in the same!

They are terminated to the same bar.

GlennDog

leftwinger57 wrote: »

I certainly would ask a lineman or an electrician can this be done to be on the safe side. As far as I saw everyone here admitted they were not electricians and certainly can't know codes of every state.

Exactly. Each AHJ (Authority Having Jurisdiction) has the end-all-be-all say so in the way buildings are constructed. 'Round here, detached structures like garages & out-buildings that have their own sub-panel have to have their own ground rod and the neutral wires inside the panel must "float" (meaning it must be separated from the metal panel board & the ground bus bar. Also, new construction requires 2 ground rods at the main structure. Bonding is enforced, as well i.e. above the water tank the gas line & the hot and cold pipes need to be bonded/connected thru approve connectors like a Weaver clamp with the appropriate gauge wire, 6 AWG in most cases

Glen B

dkg999 wrote: »

I would check your ground at the end of each circuit. I rewired a house that used the metal conduit for the ground, and with corrosion on each of the connections, most of the circuits had problems with grounding.

How old was the rewire work ? It takes a long time for corrosion to occur, unless the conduit is in a damp environment or close to the ocean.

mufsoman

Going back to my question in post #13......"So I will have 2 amps, 2 subs, AVR and the rest of the gear to plug in. I was planning on having one circuit for each amp and a third for all else. Three dedicated circuits total, either 15 or 20 amps each."

What are your alternate recommendations???


BTW, making contact with an electrician through church so I can verify panel capacity.....I'll provide an update afterward. However, from what I have learned/read, although there's 7 slots open in the panel, the real judgement of capacity comes down to potential amp load at any given time or worse case scenario vs. max load the main breaker is rated for. For that, I need to do a little more homework on amp draw of other appliances in the house. We have natural gas, so dryer, oven, stovetop, are not electrically heated, which helps a bit.

amulford

One 15 or 20 amp circuit will fill any need you have. There is absolutely no need to run more than one.

I would opt to run 12 Ga. Wire. If you ran a 15 A circuit, 14 would suffice. If you decided to increase to 20 A you would need to increase it to 12, so save yourself the hassle ahead of time.

Take the time to run it isolated from other lines. I would, if possible, run it in EMT and ground the conduit at the panel. This would help shield the circuit from stray EMF noise and drain it away from the gear. So you will run 3 conductors (hot, neutral, and ground) in the conduit, and attach a ground to the conduit at the panel end of the run.

Glen B

I run my 2-channel and HT system each on a single 20A circuit, and have never had a problem. The HT system circuit has running on it a 100W x 5 AVR, 200 W x 2 amp, two powered subs, EQ for the subs, two cable boxes, DVD player, and flatscreeen TV. Everything is connected through my Belkin PF-60 line conditioner, which displays current draw, which has never been more than 7 amps at normal listening levels. The HT circuit is run with 12 gauge type AC armored cable, and the 2-channel circuit is run in EMT, with individual type THHN/THWN 10 gauge wires for hot, neutral and ground.

Speedskater

Sometimes in the home theater forums you read about people several very big amps and more sub-woofers on just one 20A circuit. If you turn the amps on one at a time, you can play 'train wreck' movies way to loud on just one circuit.

F1nut

......"So I will have 2 amps, 2 subs, AVR and the rest of the gear to plug in. I was planning on having one circuit for each amp and a third for all else. Three dedicated circuits total, either 15 or 20 amps each."

One 12 gauge, preferrably 10 gauge 20 amp line will be fine for that, but if you can, run all 3. Nothing better than ample clean power.

rtart

IMO, you can never have too much electrical capacity to your HT. If you are running new wiring, I'd suggest 2 - 20A circuits at a minimum. I'd also run a couple 15A circuits, too. Wire is cheap to install during construction, but not so much later if you need it.

Rarely does power needed decline as your HT 'evolves'. My main power amp is fed by two power cords, both rated at 15A minimum each. I run the amp on two dedicated 20A circuits, and have one more 20A for the other amps (I run 9.1, two monster subs and three powered speakers) and a fourth 20A circuit for the other gear like BD players, cable boxes, server, etc. I also ran a spare for expansion, if I ever need it.

The thing to remember is that if your gear runs out of power, it won't 'tell you' by shutting down or thumping, etc. It simply won't reproduce the source material as well as it could. For example, if there is a huge explosion in a movie and your sub runs out of electrical power, the 'boom' won't be as loud as it could have been. The term is 'dynamic headroom', and some of us have paid a LOT over the years to maximize it. Modern BD sources have immense dynamic range, and sound great....if your gear has the power reserves to accurately reproduce it. If the amp runs out of power, it simply does the best it can. Kind of like a race car with a carb restrictor plate. It can do more, but is limited.

I really don't need most of the power my HT has....most of the time. But, once in a while, the source calls for a LOT of power, and because it is available, the result is sometimes very dramatic. I've had people leave my HT during the U-571 depth charge scene, while played at reasonable sound levels. The boom is just visceral, and unexpected...and just what I intended!!

mufsoman

As rtart says above, I never understood it to be capacity as much as its headroom and separation to avoid cross interference from the various heavy users in the rig. I have been running all my gear except one sub from one 10 amp circuit without ever blowing the breaker. The separate dedicated circuits are for (mainly) separation of the amps from the rest of the system.

With that said, I have always wondered why 20 amps? I doubt the average rig doesn't pull anywhere near that even when cranked, so why not 15 amps?

rpf65

You want to run a 20A capable, because you can use a 15A outlet on 20A wire. You can't use a 20A outlet on 15A wire. Better to spend the extra money up front, and not worry later. Some amps require a 20A outlet. Just change the plug yourself.