Running dedicated power lines - need advice

@Paul When running 2 circuits for audio use (to the same location), should both be on the same phase? If it doesn’t matter, should you wire both with separate Romex or could you use one 3 wire Romex (with ground)? Are there an advantages/disadvantages to one configuration or the other?

I would lean towards separate Romex. Two hot wires in the same polarity will interact and I believe it alters the magnetic field for the worse.

I’m confused by your answer. Are you saying to run two Romex but put them on different phases? Or two separate Romex on the same phase? If you run a 3-wire with ground, the neutral is common so the two hot wires are required to be on separate phases. So there are three possibilities - which one?

Sorry, I was saying no to the 3 wire with ground. You don’t want two hot wires on the same polarity in close proximity to each other. @raystone1998 I wouldn’t share the neutral… I believe you have the potential for noise sharing among the devices… not sure. I’m not sure the mechanism exactly but many have advised against having gear on different polarity than each other.

Run two separate Romex on the same phase with each other. Also, I highly recommend trying some BAV power cables if you haven’t already !

I’m assuming from your answer that what I call phase is what you are calling polarity. Then the problem is getting two breakers on the same phase in the breaker box which is almost full. Installing double breakers is possible but without rebalancing the existing house circuits, getting two new circuits on the same phase will be a challenge. Upgrading the breaker box would break the bank…

If it is wired traditionally you’ll want to skip one slot if you wire the two circuits vertically. Or if they are horizontal you wire them right next to each other left/right. Have you taken the cover off to see the different “legs” ?

I wish when I ran 2 extra dedicated circuits that I also put at least one on the opposite side of the room behind me in case I ever ran subs out the back or rears Wireless speakers


Need advice on my issue guys… electricians laid one metal conduit but I learned just recently that he plan to use the metal conduit as common ground. I was planning to put in 3 dedicated 10 gauge circuit, but there isn’t enough space in the conduit for individual dedicated ground cables.

Couple questions:

first: Is dedicated ground the desire here? or this would increase potential for ground loop.

second: Is it OK to run 12 gauge ground with 10 gauge wires?

What are my options?

  1. Assuming dedicated ground is desired. I can do one dedicated circuit 20 amp 10awg circuit with 10 awg ground. The other two 20 amp circuits will be 12 awg with their own 12 awg ground.

  2. Run all 3 circuits at 10 awg, with one common 10awg ground

  3. Run one dedicated 20 amp 10 awg circuit with 10 awg ground, and use the metal conduit for ground for the other two circuits.

  4. two 20 amp 10 awg circuits with 12 awg ground for each of them, the third circuit is 10 awg with the electrical conduit as ground.

Any recommendations? electrician will be back tomorrow to pull the cables.

Thanks! I guess it paid to clarify… dedicated circuit mean different things to different people. Lesson learned for me, hope it will benefit those that will do this in the future.

Dedicated ground is desirable. This reduces the potential for ground loops as all tie back to the same place.

Yes, it’s fine to use 10awg for the load carrying conductors and 12awg for ground as 12 is rated to 20amp in typical household distances.

Of the choices I like #1 then #4. The key to our needs is that all 3 conductors in the circuit are independent of any other circuit(s). Secondarily is the wire gauge.

My only concern with #4 is how good will the connection be and continue to be as time goes on with the conduit serving as ground.

Thanks, I’m leaning toward #1 actually… I rather have consistencies in the circuit. I only need one 20 amp anyway… the other two are for future use, so it’s good to have one right one.

The bright side to this is I have both dedicated 10 awg circuit and 12 awg one in the same room, I can test to see if that’ll make any difference at all. And I guess that’s also part of the fun.

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It’s not uncommon in residential and commercial installations to use the conduit for the equipment grounding conductor. That being said, if it use me, I’d prefer a dedicated equipment grounding conductor wire. You don’t need a dedicated ground wire for each branch circuit, you can use a single 12awg ground wire in the conduit to use in parallel with the three circuits. Even though you are using 10awg for the hot and neutral to compensate for voltage drop, they are still 20Amp circuits. As a result, 12awg will suffice for the equipment grounding conduct.

OK, so 12 awg common ground is OK. I like that actually.

I’ll chat with the electrician tomorrow to see what are some of the realistic options… those options are all mine :slight_smile:

I found this link from PSA:

Dedicated AC lines form star grounds. In the PS Audio Music Room we have multiple grounded AC receptacles on dedicated lines. That means that each AC receptacle has its own wires running back to the central breaker box where the main ground is also located. If each piece of gear is plugged into its own dedicated outlet, then you’ve formed a star ground.

According to that article… I guess option #1 is still best.

I am planning to do three 8 gauge home runs to the drop points and 10 gauge up to each set of dual outlets. Ground will be dedicated per run.

Yeah… wished I paid enough attention to discuss grounding, so the job can be priced correctly and the with the correct size conduit… sounds like you got a good plan there.

Currently looks like running #12 common ground is going to be it for me, some of the #10 has already pull to the receptables. Either way it’s going to cost me extra money to redo. I’ll try this option first.

I would never plug in, say two monoblock amps, into two separate circuits. Your whole system should not tax a 20 amp circuit so don’t spread your interconnected equipment across them. At a minimum, you could introduce ground loops.

I took my two VTL Deluxe 300 amps to a stereo shop to audition a pair of Magnepan speakers. I wanted to hear how my VTL amps worked with them. The store plugged each into a different circuit in the room. The amps went into oscillation. Cripes!!! Plugging both into the same circuit resulted in stability.

Now to be fair, VTL did not make great stable amps. I know this because of issues I had in Center City Philly when we would have voltage sags (brown outs). But still, this should not have happened in this high-end stereo store. The owner did not know why it happened, but we assumed each circuit had differing loads on them from other equipment plugged into them.

In short, I don’t see the value in plugging in equipment that is interconnected across circuits. I think you are asking for trouble.

I wired both my previous and now my current home with a single dedicated 20amp cuircuit with a quad outlet. ALL of my interconnected equipment is wired to that one quad outlet. Same for my home theater… to another dedicated 20 amp, quad outlet.

Just calculate your draw and you will see it does not add up close to taxing a 20 amp circuit.

So… really you just need one dedicated circuit for your interconnected audio equipment. Other circuits are for auxiliary use such as lights and such.

Bruce in Philly

Yup, agreed. That was my plan. One circuit for 2 ch audio, one for my Home Theater AV gears, one for PC, and miscellaneous.

For me though, I can see potential for ground loop, for example between AV Pre and BHK Pre (HT bypassed). So hoping I won’t run into ground loop issues.

The other thing I would do in this situation, is connect all three circuits in the load center (breaker panel) to the same phase, either all on A-phase or B-phase. This way there wouldn’t be any difference plugging all your equipment say out of one receptacle bank or spreading the equipment connections across multiple receptacles connected to the same phase.

Got to a 100% 2/3 solution. Pretty proud of myself for having thought of this. We combined two circuits into one, and was able to run dedicated star ground with all 10 awg cabling, both on the same phase. So now I have one for dedicated two channel listening and one for every thing else.

There is an easy access if in the future I want to split the combined circuit back into individual ones simply by running another dedicated wires to the junction box. I doubt I will need it though.

An update after some planning with my electrician.

I’ll be doing two 75ft 6 gauge runs to target a Vd of 1% to 2 gang boxes. I’ll be using the PS Audio outlets.

He’s also going to add a second grounding rod bonded to the main ground and new ground circuits, to lower the ground impedance to less than 10 ohms. We may redo the main ground as well to target the 10 ohm goal.

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