Studies On Residential Power Line Noise - Part 1

mmadden28

I'm about to run a new 20a dedicated circuit. I already have the 12/2 wire unopened so I can return it.
I guess if I am going through the effort is it worth doing 10 gauge instead (not sure how much more the cable will be)

Also perhaps you can answer this--What about going 240 V for my equipment that can work with it (typically the amps that are better off direct to the outlet? Do you think that would be better or worse than 120v, with respect to power quality / line noise. And if so, what wire 12/3 or 10/3? With higher voltage I'll draw less current-so not sure if guage is as important there.

Thanks

WilliamM2

mmadden28 wrote: »

I'm about to run a new 20a dedicated circuit. I already have the 12/2 wire unopened so I can return it.
I guess if I am going through the effort is it worth doing 10 gauge instead (not sure how much more the cable will be)

Also perhaps you can answer this--What about going 240 V for my equipment that can work with it (typically the amps that are better off direct to the outlet? Do you think that would be better or worse than 120v, with respect to power quality / line noise. And if so, what wire 12/3 or 10/3? With higher voltage I'll draw less current-so not sure if guage is as important there.

Thanks

Skip the 10/2, go with 12/3 and you can install 2 20amp circuits. I doubt code will allow you to run 240v to wall outlets.

mmadden28

WilliamM2 wrote: »

Skip the 10/2, go with 12/3 and you can install 2 20amp circuits. I doubt code will allow you to run 240v to wall outlets.

Of course I'd also put in the appropriate receptacle.

WilliamM2

mmadden28 wrote: »

Of course I'd also put in the appropriate receptacle.

Pretty sure that 220v outlets are only allowed for dryers and ranges. Maybe one of the electricians here can comment.

DarqueKnight

You should consult with a local, reputable, licensed electrician. Codes can vary a lot by locale.

SCompRacer

If you are a DIY and you are going to use 12/3 for two circuits and share a neutral....the breakers must not be on the same bus. That is breakers above and below one another, never across from one another, in the breaker panel. If you put both breakers on the same bus when sharing a neutral, you can overload the neutral.

For audio, I prefer seperate neutrals and grounds for each circuit. Even when using pipe.

mmadden28

DarqueKnight wrote: »

You should consult with a local, reputable, licensed electrician. Codes can vary a lot by locale.

I likely would-I'm just wondering if it might yeild better results for my audio setup. Vs. using a thicker guage 120v setup.

It seems so far though that sticking with a 120v 20amp setup is much less complicated.

mmadden28

SCompRacer wrote: »

If you are a DIY and you are going to use 12/3 for two circuits and share a neutral....the breakers must not be on the same bus. That is breakers above and below one another, never across from one another, in the breaker panel. If you put both breakers on the same bus when sharing a neutral, you can overload the neutral.

For audio, I prefer seperate neutrals and grounds for each circuit. Even when using pipe.

Lost me there--Are you saying that (if going that route), that the breakers should be on the same side/above one another? Or should be across from each other?

SCompRacer

mmadden28 wrote: »

Or should be across from each other?

Across from one another would be on the same bus, or leg. One below the other would put each breaker on a seperate bus, or leg of the two incoming 120 volt lines. You need each breaker on a different leg, or phase, to share a neutral. Otherwise, the neutral would see the combined load of both hots if they were on the same leg, or phase.

mmadden28

SCompRacer wrote: »

Across from one another would be on the same bus, or leg. One below the other would put each breaker on a seperate bus, or leg of the two incoming 120 volt lines. You need each breaker on a different leg, or phase, to share a neutral. Otherwise, the neutral would see the combined load of both hots if they were on the same leg, or phase.

I think I got it-something in your phrasing was throwing me off.
So the shared neutral is not really an issue with two separate 12/2s then? Only when sharing a neutral?

Thanks

SCompRacer

mmadden28 wrote: »

So the shared neutral is not really an issue with two separate 12/2s then? Only when sharing a neutral?

Thanks

Correct. Then there are box fill requirements to adhere to. Calculations are performed based on the wire gauge and amount of wires, and the devices (switches, outlets) that will go into the box. You need to use the proper size box to be in code. The DIY'er can find all the information to do this job properly, including getting copies of local code, but sometimes it is best to have a qualified professional do the job.

You will find opposing viewpoints on shared neutrals and isolated grounds, even among electricians. I have had less problems and a lower noise floor with my audio gear using circuits with seperate neutrals and isolated grounds, than in homes with shared neutrals and shared grounds.

tugboat

Some of us have to deal with dirty power and overtaxed circuits. Where I live, my apartment has one 20A circuit for 12 15A outlets and one 15A circuit for 4 ceiling lights! If I vacuum with the AC on, breaker blows. If I have the bathroom heater on during my shower and someone makes toast, circuit blows! My vintage system's lights dim when the AC kicks in and my vintage TV shows snow when someone vacuums!

Someday clean power will be mine!

mmadden28

When I was replacing the dimmer for my family room light and I shut the breaker off for that circuit-my HT shut down. It was then I realized how much was on that same circuit-ahh a digital dimming switch on the same circuit as my HT??? :eek: Ahhhh-that has to be pumping some gremlins in there somehow.That was when I decided to run a dedicated circuit.
I suppose my conditioner/line filter is helping with noise, but not with capacity-especially since the XPA-5 likely needs its own circuit.

tugboat

mmadden28 wrote: »

When I was replacing the dimmer for my family room light and I shut the breaker off for that circuit-my HT shut down. It was then I realized how much was on that same circuit-ahh a digital dimming switch on the same circuit as my HT??? :eek: Ahhhh-that has to be pumping some gremlins in there somehow.That was when I decided to run a dedicated circuit.
I suppose my conditioner/line filter is helping with noise, but not with capacity-especially since the XPA-5 likely needs its own circuit.

I never used dimmers because of the noise they introduce in AM radios and older radios. Sad thing is I use compact fluorescent everywhere except my lava lamps and fridge. I know they're introducing noise. Maybe I'll borrow my brother's scope and check, but I have a feeling I'm not going to like what I find! That and I think I need a new breaker. When my AC kicks in, the breaker makes a loud vibrating sound. Heard that was a sign it was getting weak.

mmadden28

WilliamM2 wrote: »

Pretty sure that 220v outlets are only allowed for dryers and ranges. Maybe one of the electricians here can comment.

I can see that.
just FYI-I have a 240v circuit going to my outdoor pool equipment as well.
That pump pulls over 3500watts

gdb

WilliamM2 wrote: »

Pretty sure that 220v outlets are only allowed for dryers and ranges. Maybe one of the electricians here can comment.

220-240v wall receps are very common and are used to power big BTU window ACs, you just use the proper recepticle/box combination.
If you are going to run this voltage you need a breaker designed for it, a double thick unit with 2 toggle switch levers tied together so if one "leg" trips, they both have to trip together. If using two separate breakers there are connectors available to snap over the toggles to join them but I always prefer the single, dedicated use breakers. Don't forget to throw the "main" before taking the cover off your service panel, and have a friend standing by with a 2X4 to knock you away from it if you get 200amps of juice into you.
It's not often, but mains can malfuntion!:)gdb

gdb

tugboat wrote: »

Some of us have to deal with dirty power and overtaxed circuits. Where I live, my apartment has one 20A circuit for 12 15A outlets and one 15A circuit for 4 ceiling lights! If I vacuum with the AC on, breaker blows. If I have the bathroom heater on during my shower and someone makes toast, circuit blows! My vintage system's lights dim when the AC kicks in and my vintage TV shows snow when someone vacuums!

Someday clean power will be mine!

If your place is wired like that you should go to the local Govt. or State, and report it to the permits and inspections dept. The receps on a 20amp circuit have to be rated for 20amp service. If you make a formal report/complaint it SHOULD force your landlord to bring everything up to safe and modern code standards ! Good luck ! gdb Also, check and make sure that the wire/cable leaving the 20A breaker is 12ga and not 14ga, very dangerous !!!:eek:

ben62670

220-240v wall receps are very common and are used to power big BTU window ACs

Yep. They are also located in garages for air compressors. I would be cautious if there are kids around. A wire from one leg to the other can be a very bad thing. Also on the comment on sharing a neutral most of the energy is burnt up in the device, and doesn't need to return to ground;) I have not tested this in a while, but the currant on the neutral is minimal. I personally would take two 20 amp lines over a single 30. Also how are you going to have a 30 receptacle in the wall? You would need an adapter. Also tripping a 30 amp breaker would be insane. Some guys run 10ga for 20 amp circuits which is fine, but I personally would rather have 2 20's. Then you could always run 10/3 with 20 amp breakers.
Ben
Ben

tugboat

gdb wrote: »

If your place is wired like that you should go to the local Govt. or State, and report it to the permits and inspections dept. The receps on a 20amp circuit have to be rated for 20amp service. If you make a formal report/complaint it SHOULD force your landlord to bring everything up to safe and modern code standards ! Good luck ! gdb Also, check and make sure that the wire/cable leaving the 20A breaker is 12ga and not 14ga, very dangerous !!!:eek:

This is after being rewired and inpsected. You don't need 20A outlets on a 20A circuit unless you only have one outlet. Once you have multiple outlets of 15A, all is well and up to code. Before the rewire job, I had the old original cloth covered wire on a single 15A circuit. Now I have new 12ga for the hots and the old cloth covered 12ga for the neutral. The box and conduit are the grounds I guess.

Forgot.... I have all 20A outlets anyway. I changed them out myself years ago.

ben62670

gdb wrote: »

If your place is wired like that you should go to the local Govt. or State, and report it to the permits and inspections dept. The receps on a 20amp circuit have to be rated for 20amp service. If you make a formal report/complaint it SHOULD force your landlord to bring everything up to safe and modern code standards ! Good luck ! gdb Also, check and make sure that the wire/cable leaving the 20A breaker is 12ga and not 14ga, very dangerous !!!:eek:

Not true. if there is a single receptical on a circuit it has to be rated for 20amps. 99.9% of duplex outlets are rated for 15amps.
Ben

gdb

I suggest that you buy one of the cheap orange recepticle testers with the LED indicators and see what it tells you, if they "fudged" by combining new and old cable, they might have reversed hot and neutral or left an "open" ground situation. Wouldn't hurt! gdb

tugboat

gdb wrote: »

I suggest that you buy one of the cheap orange recepticle testers with the LED indicators and see what it tells you, if they "fudged" by combining new and old cable, they might have reversed hot and neutral or left an "open" ground situation. Wouldn't hurt! gdb

I have a tester and all is well. I won't plug anything in without testing it first. What really bugs me is that they should have made two circuits for the outlets, but the didn't. They said that since they were not changing over the neutral wires, they couldn't make two circuits out of them. So for some reason they could pull the old hots and pull new, but not the neutrals. Go figure.

DarqueKnight

gdb wrote: »

The receps on a 20amp circuit have to be rated for 20amp service. If you make a formal report/complaint it SHOULD force your landlord to bring everything up to safe and modern code standards

Like Ben and tugboat said...no, not if there are multiple outlets on the 20A circuit. Refer to posts 43, 45, and 47 of this thread to find out why.

mmadden28

DarqueKnight wrote: »

Like Ben and tugboat said...no, not if there are multiple outlets on the 20A circuit. Refer to posts 43, 45, and 47 of this thread to find out why.

I actually get this now. Good stuff to know.

ben62670 wrote: »

... I personally would take two 20 amp lines over a single 30. Also how are you going to have a 30 receptacle in the wall? You would need an adapter. Also tripping a 30 amp breaker would be insane. Some guys run 10ga for 20 amp circuits which is fine, but I personally would rather have 2 20's. Then you could always run 10/3 with 20 amp breakers.
Ben
Ben

Who's running with a 30a recepticle or a single 30a circuit? I can't find that mentioned in this thread.

DarqueKnight

WilliamM2 wrote: »

Even better would be some measurements at the analog outputs.

I agree.

Please refer to figures 8, 10, 12 and 14, and their associated discussion, in part 2 of this series here.

Enjoy.

bilbeau

I'd like to see as someone else mentioned earlier some recorded measurments of the outputs from the power supply inside an amp. These power supplies are designed or I should say a well designed power supply will correct these issues with dirty power.

I feel sometimes that these high dollar power cords are a bit much. Someone needs to prove to me through the use of a O'scope that the power supply is putting out cleaner dc voltage to the system through the use of one of these magic cords.


Just my $.02 worth

DarqueKnight

I'll inform the commander that Lord Vader's shuttle has arrived.

F1nut

Use your ears, no better tester in the world.

DarqueKnight

What if you can't trust your ears? What then?

F1nut

Well, one could look at that as a blessing or a curse.