AC Power Question

+1 @millercarbon 
I tried initially using two runs and ran into hum issues. Now I use one run of 8 gauge on a 20A breaker into a Hubbell L20R/L20P.

Its amazing how this simple subject always gets bogged down in complexity and code and comments, usually from people who've never done and so don't know what they're talking about. I've actually had the standard normal house wiring, and then run a dedicated circuit, and then run an even better dedicated 240v to a step down transformer. Say again, I've actually done the wiring and listened and compared.

Your best cost option is to put everything on one single circuit, conservatively rated. i.e. use 20A even if you could get by code with 15. Do not run two circuits. If you do then put all your audio on one, all non-audio (record cleaner, lights, etc) on the other. As someone correctly noted it takes only a very tiny difference in ground potential to produce hum. Again, I know for a fact and from experience you can and will get hum when different components connected to different circuits are connected together. Different manufacturers follow different construction so that what looks the same is not. i.e. just because you see a ground plug does not mean the manufacturer connected those pins with a wire! So you may sometimes get away with it. Or you may just give yourself a headache.

One circuit. KISS. Capiche?

Just got my electrical inspection a few days ago. Inspector kept asking me why I put in 10 gage wire and an outlet that didnt cost 1.49

I put in a dedicated 20A line that feeds a P15 regenerator. With everything running I'm not even pulling 5A. 

I can't speak high enough about the monumental change the regenerator made to my system

jea48

I don't know if its NRTL tested or if it can be used in the US, Ive been living in Vietnam for 8 years now, I left the states 22 years ago and have no idea whats allowed or not allowed as far has electrical code.

The ebey link does not show the proper EE 2.6, ( I only see two internal wires)  all the EE 2.6 I have seen or purchased came with three internal wires, neg,pos, grnd.

I meant Romex, I think 10g solid is fine for digital gear but for analog 8g. solid made a noticeable improvement.

I use Acoustic Revive EE 2.6 solid copper 10g. in wall cable to Furutech GTX R NCF outlets for the digital front end, preamp & amp each have there own seperate 8 g. solid core copper to Furutech GTX R NCF outlets, this is a huge improvement over standard Rominex 10g. stranded wire especially with the amp and preamp having there own separate dedicated lines.

My situation is a 15yr old house governed by Canadian electrical code, which is for the most part consistent with the US NEC. The reason the builder used 14/3 for those branch circuits was purely economics based. In Canadian electrical code, a clothes washer circuit is only required to be 15 amp. Should it be on its own? - yes! Should it be 12/2 instead? - yes! But, the reality is this house was built in a large development project, and they didn’t do things to meet ideals, they based every decision on the bottom line. One fine day, I will get around to running a dedicated 12/2 for that clothes washer. As an intermediate stage, I removed the lighting circuit from the other leg of that 14/3 and put it on a dedicated 14/2, which has improved the lifespan of lightbulbs. 

As my questions should suggest, I understand how these circuits work. What I don’t understand is how the load on one phase can influence the current on the other phase, unless there is something wrong with the electric service in the first place.

Shared neutrals are absolutely allowed under NEC and I see no reason to avoid them.

@cleeds 

Will you please explain what "back-current" is? If you have a 14-3 cable, then each of the hot wires come from different legs of your service, correct? (After all, that's why they can share a neutral.) Please explain how a changing load on one leg can influence the voltage on the other leg.

If your 14-3 cable is connected to the same phase (leg) of your AC service, that's a code violation because of the shared neutral, no?

On a shared neutral such as 14/3, the back current is reverse flow from the red leg affecting the neutral potential for the black leg and vice-versa. That’s why shared neutral circuits sometimes use a smaller gauge neutral conductor. When both sides are steady loads, such as lighting, you can do shared neutral, but in the case of the circuit powering my clothes washer, the other leg powered a lighting circuit, which caused the lights to flare when the washing machine was changing cycles and electrical demand from it surged. 

Shared neutral circuits must never have both hot conductors on the same leg of breaker panel. That would cause the neutral load to reach double the current rating, and create fire hazard. Shared neutral should be against code in my opinion. The correct use for 14/3, 12/3, 10/3 etc... is 240 volt loads that require a neutral conductor, or sub panels. 

https://solargenerator.guide/goalzero-3000-lithium-solar-generator-review/
An interesting product that I've only reciently heard about. I would be interested in reading some Audio reviews regarding it. Also interested in how many years the lithium batteries last and the replacement cost.

Forget dedicated lines and simply get  Goal Zero Yeti lithium power station - anywhere from 1000w to 3000w depending on your needs.  The cleanest power.
No need for fancy conditioners, cables or anyting.
Simply 

@mental , Before I had work done, i inquired on a thread and @jea48 participated with excellent instructions on the optimal setup of mains power to an audio system. @almarg joined the conversation and as always I valued his input.
After the installation of a subpanel hosting 2 dedicated lines on the same phase and an added ground rod, with Romex wired independently to separate Hubbell duplexes which are grounded back to the service panel. I came back to the thread to review with jea48.
Jea48 asked me specific questions regarding the hot, neutral, and ground. I actually called my electrician to get the correct facts, presented them to the forum, and was told it was done correctly.
It’s one of the best upgrades added to my system.

Same leg means same phase and you just caused an imbalance at the main panel.

The load from the audio lines is minimal. I asked the electrician to balance the load to both legs at the panel. He did a ampere calculation and moved some breakers to balance the current demand on the two legs; eg, refrigerator on leg A, air conditioner on leg B. Washer leg A, dryer leg B. Furnace 60A breaker shared, Subpanel 60A breaker shared.

2 phase panel 60A total.
60A subpanel.

sleepwalker65

... they used the other leg on that 14/3 for lighting in the first floor. Every time the clothes washer was running and switched cycles, the lights would flare. No wonder they would burn out so often, with all that excess back-current!

Will you please explain what "back-current" is? If you have a 14-3 cable, then each of the hot wires come from different legs of your service, correct? (After all, that's why they can share a neutral.) Please explain how a changing load on one leg can influence the voltage on the other leg.

If your 14-3 cable is connected to the same phase (leg) of your AC service, that's a code violation because of the shared neutral, no?

I think dedicated, de-rated, 20A lines are the way to go. If you think you might need two lines, then get three. If you think you need three, get four. It’s less expensive and invasive to do it all at once.

I am also a major believer in getting an electrical construction permit before commencing work. Your local electrical inspector is your inexpensive QC against shoddy work - we’ve seen examples of that here on Audiogon - or a simple error. And the approved permits can be useful when you it’s time to sell your house.

I have dedicated lines on both legs of my service, and don’t see or hear a difference between them. YMMV. My system benefits from isolation transformers and power conditioning all around, including on amplifiers. They make a huge difference, and all for the better.

While you’re doing this work, it’s wise to check the other aspects of your power. Are all connections clean and tight? Is your grounding up to current code? And here’s the most overlooked detail, imo: Can your electric utility deliver sufficient current? If you think your "200A service" means that your utility can deliver 200A of current, you are almost certainly mistaken. Do your lights dim substantially when you turn on your power amp? That can be a clue to current delivery issues.

Being an Electronics Engineer, I live in both sides of this equation. Take this example:

Builders do the dumbest things you can imagine, which further compounds issues. For example, my 3000 sq ft house has a second floor laundry near the front of the house, and the breaker panel is in the basement on the opposite side near the back. In their infinite wisdom, they ran 14/3 Romex for the circuit that powers the clothes washing machine, which is some 130 feet long. The punch line is this: they used the other leg on that 14/3 for lighting in the first floor. Every time the clothes washer was running and switched cycles, the lights would flare. No wonder they would burn out so often, with all that excess back-current! I fixed the problem by running a new 14/2 circuit just for the lighting, and one day, when I feel more motivated, I’ll run a new 12/2 for the 15 amp circuit feeding that clothes washer. 

The electrician and the audiophile. Apart from safety and codes - obviously important to both parties - will never be in agreement about what happens to sensitive audio gear at the microvolt level. #sameleg

The load placed on each of Lowrider57’s circuits is minimal and relatively steady. Placing both on the same leg is good practice based on the application. If you think you’re going to have a perfectly balanced panel just by arbitrarily splitting loads, you are in fantasy land. The only way to balance a panel is by doing measurements, and even then at one instant the balance will be different than the next. 

@jea48 and @almarg are the experts on this subject. Hopefully one of them will join in.

They advised me when installing my dedicated lines. I'm running my analogue and digital on separate dedicated 20 amp circuits into separate Hubble duplex receptacles. In my case, I have a subpanel for my audio lines.

Both lines on the same leg with equal distribution of current draw from devices and appliances
to the sevice panel. 

noromance"if using two runs off two breakers, make sure they are on the same phase or you could get noise"

That is myth, fiction, and misinformation there is no truth, validity, or basis for this claim where do you think the "noise" will come from!

Good advice all....

Correct me if I'm wrong but if using two runs off two breakers, make sure they are on the same phase or you could get noise. I used 8 gauge on a 20amp breaker.

The cost difference assuming you have the breaker space for it is almost zero, so go for 2 x 20.  This requires only 1 more conductor.

You can underrate, which is a little safer. Choose 15 A breakers, but 12 gauge wiring. You get the low resistance of the thicker copper, but the safety of the lower tripping point.

Also, you may need a cable TV ground isolator. Might as well get one, they're cheap and prevent ground loop issues later.