220V vs 120V - Any benefit?

[whoaru99]

I may be new @ this but from what I have read earlier in other posts (read australia/europe) was that in those countries the 240vac is carried on ONE current line and one neutral (please correct me if I'm wrong), I think that would be a more efficient power delivery to an amp than 2 120vac lines. I dont know if the 240vac input on your model is setup for 2 120vac lines or a single 240vac. I may be wrong but it think it'd be bad to connect the 2 phases together of our 240vac (a short perhaps?) here in can/usa. I think europe/australias 240vac is wired like our 110/120vac if i read it right.. that could cause issues perhaps... one single 240 vac hot vs 2 120 vac hots(aka dryer plug) ... different to me on a basic level.
Regards.
A.

I can't speak to the power systems in Europe or Australia, but here in USA the word "neutral" is usually misused. It's often common slang for what is technically the grounded wire of a typical 120V circuit.

Technically, the only place a neutral wire exists in general home wiring is in a 120/240 circuit.

Don't let the 120/240 thing fool you. Either way, it takes two conductors to complete the circuit. 120 is taken hot to ground, 240 is taken hot to hot. The appliance doesn't know the difference either way (so long as it's configured for the right voltage )

In countries where there is only 240, it's likely the power is hot to ground, but really no different other than the voltage. It's still two wires to complete the circuit.

 

[nashvillebill]

I may be new @ this but from what I have read earlier in other posts (read australia/europe) was that in those countries the 240vac is carried on ONE current line and one neutral (please correct me if I'm wrong), I think that would be a more efficient power delivery to an amp than 2 120vac lines. I dont know if the 240vac input on your model is setup for 2 120vac lines or a single 240vac. I may be wrong but it think it'd be bad to connect the 2 phases together of our 240vac (a short perhaps?) here in can/usa. I think europe/australias 240vac is wired like our 110/120vac if i read it right.. that could cause issues perhaps... one single 240 vac hot vs 2 120 vac hots(aka dryer plug) ... different to me on a basic level.
Regards.
A.

Doesn't matter if it's European or US, there are still a minimum of TWO current-carrying conductors in any circuit. The issue that confuses everybody must be the way the "legs" are labelled..."hot", "neutral", ground...Think of a simple circuit, say a battery and a load. A wire is attached to the positive (+) post and one to the negative (-) post. Break either wire and put an ammeter there, you'll still get the amount of current that the load is drawing. And you must have two wires, one "going to" the load and one "coming back". Although one wire is labelled "negative", there's still current going through it.

Substitute the power company's electrical generating station for the battery, and the load is now the transformer in the amp. Two wires attach to the transformer, and go back to the receptacle (the ground is a third wire, but it's there as a non-current-carrying safety so we can ignore it as far as current). Break either of the two wires going into the primary of the transformer, and put an ammeter in series at that spot, you'll get the amount of current being drawn by the amp. Doesn't matter if you look at the current in the black wire we call "hot" or the white wire we call"neutral", it's the same current in both wires. "Ground" (green or bare in the US) carries no current unless there's a fault condition.

The 240 VAC in the US really doesn't differ from the European 240 VAC, as far as having two current-carrying conductors. Europe has a "ground" too. However, in the US we add a fourth wire (if we count the ground as the third wire) to the mix...this is the white neutral in the US. This is at a voltage potential half ways between the two 240 VAC wires and we call that neutral, Europe doesn't have this "neutral" wire.

A better way is to refer to the two 240 volt wires as L1 and L2, then the voltage potential between L1 and L2 is 240 volts. The voltage potential between L1 and what we call "neutral" is 120 volts. The voltage potential between L2 and "neutral" is also 120 volts. The voltage potential between neutral and ground should be 0.

In the US, there are some appliances that are wired with 4 wires. An air conditioner, for example. The compressor draws the most current, it uses 220 volts for the least voltage drop in the conductors, it has two black wires to the load (the L1 and L2 240 volt legs). The fan motor or control boards may use 120 volts, so their power comes from the voltage potential between L1 (or L2) and the neutral wire. The fourth wire is the ground.

It's not intuitively obvious that power distribution is much more efficient at high voltages, even Thomas Edison struggled with the concept....

 

[jstang]

We could throw a monkey wrench in the discussion and start talking about Ground, Neutral and Ground faults..... but I am done for now talking about the finer points of wiring...


Few more songs and I will do some rail testing

- 30Hz into a 8 ohm load...
- 100 Watts from each channel
- Record the Rail voltage
- Record the Rail ripple
- Record the AC current
- Record VAC drop at the outlet

johnk

 

[jstang]

It's not intuitively obvious that power distribution is much more efficient at high voltages, even Thomas Edison struggled with the concept....

Tesla got it.... and he lived in my town here in NJ till he died....

Ok some initial temperature measurements with a IR thermometer....

Transformer runs cooler....output x-ters hotter....

I would expect both... the transform is more effecient because less current on the primary side being converted to heat...

Outputs hotter because of rails sagging less and being higher to start with ....


jk

 

[whoaru99]

The voltage potential between neutral and ground should be 0.

Depends on if you mean true neutral or neutral in the sense of a current carrying grounded conductor.

In the former, yes, because there is no current. No in the sense of the latter as the current in the neutral will create voltage drop with respect to the gounding wire - except where they become bonded together back at the main panel.

 

[jstang]

Depends on if you mean true neutral or neutral in the sense of a current carrying grounded conductor.

In the former, yes, because there is no current. No in the sense of the latter as the current in the neutral will create voltage drop with respect to the gounding wire - except where they become bonded together back at the main panel.

WHOARU ..... I was thinking the same about Bonding and ground...

Question about you user ID.... Does it have anything do with the Who.....


jk

 

[ugornot]

Damn late to the argument with 32 years of experience. The whole point is conductor size determines ampacity. The insulation determines the voltage. But a house with a 200 amp 240 volt service would require a 4000 amp conductor at 12 volts. Talk about some copper. The difference between 120 and 240 is there but it is not great in fact almost negligible.

 

[FalconEddy]

Raise the Voltage, the current will drop proportionally for the same POWER being consumed by the amp..... Less current equals less voltage drop voltage drop across the AC wiring....

jk

100% Correct.

I've been watching the last couple pages of this thread, smiling at some of the comments, and shaking my head at others.

It reminded me of a couple of guys I know in the area. . .one master electrician, and one master plumber. They both played in the same band and I'd run sound for them occassionally.

I'd tap into the utility supply in some nightclubs right at the single phase distribution panels, and run cables out to my rack of power amps. The first time I ran sound the electrician would argue about neutral, hot, loads. . .whatever. Then he'd say "you're gonna draw WAY to much current using 240 to those amps, and the voltage drop is gonna be huge". I tried (desperately) to explain that he was confusing the 'ability to supply' and the 'actual consumption' of current when using 240VAC, but it was like talking to a brick wall.

"Don't tell me MY business boy. I've run more circuits in my life than. . . " Well, you get the point.

One time, the plumber was talking to somebody during a break about problems with his well pump. I listened in and didn't say anything until his customer went back inside. He told the guy that he needed set the pressure switch up higher to get more water from the system. When I told him, "you know. . . you have to reduce the pressure to increase the gallons per minute for the type system he has, right?

It was a no-win scenario from that point on.

"What the hell you talkin' about? I've been sizin' and fittin' pumps for 25 years, man and boy. . . ."

When I told him, "Well Rance, you've been doin' it wrong for 25 years", he got so red-faced I thought his head was going to explode.

Yeah. . . I've also had my share of guys saying, "oh, one 'a them COLLEGE boys, huh?", "You're the engineer, why don't YOU figgur it out", "mister big-shot smart-ass", etc.

It's generally pretty tough getting people to open their minds when they think they know they're right.

(No offense intended. . . just trying to relate a couple of stories that came to mind while reading this thread.)

. . Falcon

 

[jstang]

Ok here's least round of testing YOU HAVE TO GO DOWN TO ROUND 4 BELOW....

THE REAL KICKER IS THE RAILS ARE ABOUT 9Vdc Higher.... I have seen the rail anywheres from 76 to 80 volts... never at 85Vs. NOW THEY ARE RIGHT AT 85Vdc.

AC Current draw is HALF at the same OUTPUT LOAD...

SAG IS LESS....ripple less.

I an F...Kin Tired right now...so I might rerun the test tomorrow...

But Take my word it sounds better the RAILS ARE MUCH HIGHER RIGHT AT THE FACTORY RATING OF 85Vdc which I have never seen before on this amp.... HIGH RAILS MEAN MORE POWER STORED IN THE MAIN FILTER CAPS....better response...

I did not measure AC sag as my tap is only good for 120 volts....need to work that tomorrow.

This was well worth it for me....

Thanks to the people provided helpful information... I really appreciate it!!!!!

Special thanks to Tesla....

Johnk


ROUND ONE OF TESTING...

1. Volume set to produce about 100 Watts at 8 ohms in two both channels...

2. Rails sag by 3 DC volts. With an AC component of the 1.5 volts.

3. AC line voltage sags by 3 volts

4. AC current is 5 amps.

Measurements could be off by some.... I think most of the RAIL sag is caused by the AC Line sag.

This test suggests I have a weak connection with this AC line..... But also suggests to me that 220 could help...as it should sag less.


ROUND TWO OF TESTING

I moved the system to the Washer/Dryer outlet which is 20amp breaker direct circuit....

The system sounds slightly better at high volumes and I re-ran the 30hz test 100WPC in 8 Ohm test.... the AC voltage drop is slightly
less at 2Vs.

I regularly drive my Ohm Fs to 200 WPC levels. So I think the results would be more pronounced.

ROUND THREE OF TESTING

I went back and opened the junction boxes for the first circuit and found two lose wire nuts... Tighten them and return the system to that circuit. The voltage drop is reduced under load...


At least I have a methodology to test along with the ears.... Based on the testing and the drops recorded...I think 220 could help.

FUTURE ROUND FOUR OF TESING

- 30Hz into a 8 ohm load...
- 100 Watts from each channel
- Record the Rail voltage

85Vs was anywheres between 76 & 80 ...... that is a 9 Volt gain.
1.5 V sag

- Record the Rail ripple
No load 30mV

.75v

- Record the AC current
.75A at idle
2.75A Load with 100 WPC into 8 Ohms

- Record VAC drop at the outlet

Did not do this...NEED TO MAKE UP A TAP I TRUST AT 240....

 

[jstang]

College or Master Electrician..... Matters not if you don't understand the basics....

Two things I have learned...

1. Learn the Basics and the rest will come a lot easier....

2. Learned to never be surprised at how many people don't understand the basics....


jk

100% Correct.

I've been watching the last couple pages of this thread, smiling at some of the comments, and shaking my head at others.

It reminded me of a couple of guys I know in the area. . .one master electrician, and one master plumber. They both played in the same band and I'd run sound for them occassionally.

I'd tap into the utility supply in some nightclubs right at the single phase distribution panels, and run cables out to my rack of power amps. The first time I ran sound the electrician would argue about neutral, hot, loads. . .whatever. Then he'd say "you're gonna draw WAY to much current using 240 to those amps, and the voltage drop is gonna be huge". I tried (desperately) to explain that he was confusing the 'ability to supply' and the 'actual consumption' of current when using 240VAC, but it was like talking to a brick wall.

"Don't tell me MY business boy. I've run more circuits in my life than. . . " Well, you get the point.

One time, the plumber was talking to somebody during a break about problems with his well pump. I listened in and didn't say anything until his customer went back inside. He told the guy that he needed set the pressure switch up higher to get more water from the system. When I told him, "you know. . . you have to reduce the pressure to increase the gallons per minute for the type system he has, right?

It was a no-win scenario from that point on.

"What the hell you talkin' about? I've been sizin' and fittin' pumps for 25 years, man and boy. . . ."

When I told him, "Well Rance, you've been doin' it wrong for 25 years", he got so red-faced I thought his head was going to explode.

Yeah. . . I've also had my share of guys saying, "oh, one 'a them COLLEGE boys, huh?", "You're the engineer, why don't YOU figgur it out", "mister big-shot smart-ass", etc.

It's generally pretty tough getting people to open their minds when they think they know they're right.

(No offense intended. . . just trying to relate a couple of stories that came to mind while reading this thread.)

. . Falcon

 

[nashvillebill]

Depends on if you mean true neutral or neutral in the sense of a current carrying grounded conductor.

In the former, yes, because there is no current. No in the sense of the latter as the current in the neutral will create voltage drop with respect to the gounding wire - except where they become bonded together back at the main panel.

Yep, I agree, when I measure neutral-to-ground at the load end of a circuit, there is a small voltage difference...

And many people do not realize that wire must be sized first for ampacity but secondly for voltage drop.

I try to run all big loads (table saw, air compressor) on 220, so it makes perfect sense to me to run a big power amp on 220. I've got a QSC power amp for my PA, 1.8 KW, too bad I can't hook it up to 220 on our gigs...

 

[jstang]

Yep, I agree, when I measure neutral-to-ground at the load end of a circuit, there is a small voltage difference...

Could be due to inductive coupling...just like a transformer....

jk

 

[MudPuppy176]

Sorry that is not correct.... with 120V or 220v there are only 2 conductors passing current.....same number of conductors....same resistive drop.

Even if you spread the across two 120v circuits in of one 220.... WHICH I CAN NOT SEEING I AM SPEAKING ABOUT ONE AMP....the drop percentage wise is still greater for Each circuit....

Now even for the Service side out at the Poll all of this hold true....

Oh by the way where you are making the mistake is in thinking that you have DOUBLE THE CURRENT.... WRONG....for the same power delivery the current is halved on 220 vs 120. Which is why Higher voltage is more efficient for long haul....

I guess you are aware of Ohms law .... But never understood P=IE.....

You're not really an electrician...NOW ARE YOU.....

jk

I drew you a little illustration to maybe help you understand. If load 1=load 2, there is no current through the neutral therefore no voltage drop (essentially halving the wire length). Load 3 utilizes 2 wire lenghths at half the current for the same voltage drop. As I stated earlier, this only occurs when the loads are equal. You're not really an engineer...NOW ARE YOU.....

 

[whoaru99]

Mud, that first circuit doesn't make sense to me either.

How can you have 2400W @ 120V total load, but only 10A flowing in and out of the circuit?

 

[MudPuppy176]

Mud, that first circuit doesn't make sense to me either.

How can you have 2400W @ 120V total load, but only 10A flowing in and out of the circuit?

They're 180 degrees out of phase so they negate each other's neutral load. They're essentially 2 120V loads in series across 240V, nothing magical.

 

[jstang]

Ok but your worried about the wiring back to the poll...and at the Mains in the box....

I am not... because have no control over that...even with noload in my home MAINS OPEN on the bad days I get low voltage from the Power Company....106 on leg... With the MAINS OPEN AND THE WIRING CLAMPS REPLACED... There is not much more I can do expect to continue to bitch to the power company...

In the mean time I have been trying to improve the wiring from the breaker box out to the outlet.... Going from a 14 gauge shared 15 circuit to 10 gauge dedicated....

Where all the math discussion is taking place is on the little tiny stubs that from the input lead of the Transform back to and including branch wiring.... That has been the prime focus....cause the drop and current carrying of part of the wire can be improved for 78$ that I spent....

I am not trying to fix what the Power Company provides to house ( even under no load ) with 78$ worth of wiring....

Oh by the you still failed.... HERE'S HIT WHY YOU FAILED

Draw a detail diagram with every piece of wire included from the Amps transformer back to the service box and back to Poll outside...Include the details of the service Box and every breaker... then start calculating the drops....

Hi level statements and diagrams like you draw are meaningless.... Remember the devil is in the details....

You know I really try to help people because people help me... But this is the last time I will respond to Mud... You can say whatever you like...you will get no response from me....


jk

I drew you a little illustration to maybe help you understand. If load 1=load 2, there is no current through the neutral therefore no voltage drop (essentially halving the wire length). Load 3 utilizes 2 wire lenghths at half the current for the same voltage drop. As I stated earlier, this only occurs when the loads are equal. You're not really an engineer...NOW ARE YOU.....

 

[MudPuppy176]

Oh by the you still failed....

You know I really try to help people because people help me... But this is the last time I will respond to Mud... You can say whatever you like...you will get no response from me....


jk

You stand corrected on all counts, whether you admit it or not.

 

[whoaru99]

They're 180 degrees out of phase so they negate each other's neutral load. They're essentially 2 120V loads in series across 240V, nothing magical.

I was hung up on the 120V thing and current, not the two 120V devices in series across 240V. So, the 10A is correct (2400W @ 240V = 10A) as you drew it.

Now, after further consideration, I see where you were going with the shared neutral circuit reducing voltage drop compared to two separate 120V circuits.

 

[nashvillebill]

I drew you a little illustration to maybe help you understand. If load 1=load 2, there is no current through the neutral therefore no voltage drop (essentially halving the wire length). Load 3 utilizes 2 wire lenghths at half the current for the same voltage drop. As I stated earlier, this only occurs when the loads are equal. You're not really an engineer...NOW ARE YOU.....

But the first drawing isn't how he's wiring his amp. For his 220 volt connection, there is no neutral connection!!! The two coils in the primary are connected in series rather than parallel, that's all. The primary is connected to L1 and L2. Again, neutral is not used as a current-carrying conductor, so vector cancellation isn't even involved.

 

[Krautrawk]

I'm an electrician, a Home Cheapo book I don't need. I'm trying to help you. Trust me, I know what I'm doing. I'm more than aware of Ohm's law, you're simply misapplying it. You're not the first engineer I've corrected.

He either does not account for whatever resistance is drawing the 1000W load or assumes the .5 wire is drawing this load, in the second case the equations are inconsistent and the problem is overconstrained. He should do a voltage divider between the wire and the load, which I'm too lazy to do, but intuitively there should not be a difference in % regulation using this ideal model. In the real world, I would expect it to be slightly worse in 220V due to increased winding resistance.

IMO this upgrade should have benefits however. It is unique that you have the option with stereo equipment of stepping up the voltage to draw less current, electronics designers would love to do this on mixed signal applications because almost all power system noise is concentrated in the supply current; anything other than very low THD on voltage is pretty rare and indicates a serious concern. The supply current drawn by PS's with large filter capacitances is NASTY and that will also feed back onto other stuff. The tradeoff of course is that any component where a dielectric constant is relevant will be more highly strained, particularly the insulation between the transformer windings. But since the transformer is sized for 220 anyway the experiment is worth doing.