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Dedicated Line Advise

I currently have a 20 amp dedicated line run to my small HiFi rig; amp, preamp, CDP, TT, power conditioning. I wish to add a second line using the same electrician who has worked on my house. It looks like he used 12 gauge Romex last time.

What are the key facts that I should know in case he is not familiar with doing wiring for audio systems?
I'm talking about the installation at the breaker box, e.g., keeping proper phase and preventing a ground-loop between the 2 circuits.
128x128lowrider57

Showing 5 responses by minorl

minorl
1,014 posts
 
Not trying to start any argument here, but there is absolutely no reason for the equipment to be on the same phase at all.  The AC is converted to DC within the device, so AC voltage phasing is irrelevant.

As long as the dedicated line have hot, neutral and ground going back to the panel and do not share neutral or ground before the panel. you are fine.

Also, any electrician worth their salt will want to have your AC panel loads balanced on both phases. 

I read that many posts about dedicated lines and some advocate placing them on the same phase.  But, if your equipment carries a large load =, that load must be balanced on the AC panel to avoid overloads.

I ran dedicated lines for my audio equipment.  My house fortunately is on a raised foundation, so crawling underneath the house was the way to go.  Hot, neutral and ground all back to the panel and not shared.

I have to Audio Research REF 250 mono amps connected to the individual dedicated lines back to the panel (on the same phase at the panel) and one Mark Levinson 23.5 connected to the other phase via a dedicated line. 

My low level equipment are all connected to a Transparent Audio Power Isolator 8 line conditioner, then via a dedicated line back to the panel.

I tried to balance the loads as best I could.

Noise floor is just gone.  No ground loops, no buzz, no noise whatsoever. no equipment's ground lifted via cheaters.

Noticeable difference from when I didn't have dedicated lines.

Being an Electrical Engineer, I know that AC is AC and DC is DC and every piece of equipment I use converts the AC to DC internally.  Therefore, phase absolutely does not matter and my system's sound is wonderful.

If you are going to put all your equipment on the same phase at the panel, try to make sure your house loads are balanced at the panel.

enjoy
minorl
1,014 posts
 

One thing that I like about Audiogon is that one can have good discussions with others here without having to worry about trolls and negative discord.  I disagree with the idea that the power feed must come from the same leg on the power panel and we had discussions about that here and yes, we do agree to disagree. 

Having the power feed from the same leg will not be a problem at all, except as I mentioned the load at the panel may not be balanced.  Which can cause electrical issues.

I have seen nor heard any evidence that having power from both legs causes any problems at all and in my case it definitely does not.

But, remember, that either way, one must not share ground or neutrals with anything.  The hot, neutral and ground leads must go all the way back to the panel. 

Other things that can and often do cause ground loops and buzzing is poor interconnect cables where the return is tied to the shield. Or, if the electrical component has a poorly designed grounding scheme. 

There are many reasons why people experience ground loops/buzzing.  The very last reason that I would suspect would be using separate power feeds from the panel. 

The ground and neutral are all tied together in the panel.  So as long as these run independently back to the panel, you are good.  I suspect bad component ground design scheme or bad/poor interconnects.

In my case, this is a non-issue and I have my power feeds balanced on both sides of the panel.  If someone has this same set up and has ground loop or noise problems, I would love to hear about it. 

Audiogon is a great place for these types of discussions.

enjoy

minorl
1,014 posts
 

Or, if your breaker panel is like mine (I just looked), if you have an open breaker position in the panel on the other phase, you can simply move the breaker in question to the other side/phase, snap it into place and you are done.

enjoy

minorl
1,014 posts
 

lowrider57;  moving hot leads from one phase to another in the panel takes no time at all for an electrician.

Adding a new box takes a little more work. 

But what you described is really not complicated. 

You could actually do this yourself if you knew how.

On my house it is simple.  I would go outside to my meter panel.  There is a large circuit breaker for my house. Yes it is that old.

I will trip off that circuit breaker, de-energizing the house feed from the meter.  (I actually don't have to do this, but it is safer), Then I would go into the house to the breaker panel in my house.  I would locate the breaker that feeds the line described, then remove the breaker, take the lead from that breaker feed and move it to the other hot phase in the panel.  reconnect the circuit breaker, turn on the main breaker and you are done.

If you are doing this yourself, just take a volt meter with you and measure that the voltage is turned off before proceeding. 

There are two hot leads coming into your home. An A and B phase and a neutral.  A is on one side of the panel and B is on the other.  They both measure 120VAC with respect to the neutral.  They are out of phase with each other.  If you open your breaker panel, you will actually see the two phase wires connected to the breaker bus bars on either side.  You will see the neutral also and a ground (which is your house ground).

If you are not comfortable doing this, an electrician shouldn't charge more that an hour's labor (that is very conservative) to do this.

enjoy

minorl
1,014 posts
 
I love these stories.  This is why it is always important to use a volt meter and check to see that the voltage is zero on the phases.

In the utility industry, one always checks hot voltage first to see if the meter is working, then check the "de-energized" circuit to see if it is zero, then go back and check the hot voltage again. to make sure there is no fault with the meter.

Also, as always, it is better to hire a licensed Electrician if one does not know how to do this.  Safer is always better.

enjoy
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