Can you recycle amps???

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  #1  
Old 12-11-05, 07:12 AM
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Question Can you recycle amps???

Hello all - what a great forum!!!

I, like many others, have always been confused on why you couldn't jump the neutral as a way to get a ground on a two wire circuit. I have read every word of the "wiring argument" thread, and now fully understand the reasoning, and I thank you all for that.

However, while reading that, I began to think about another question, and please forgive me if this is a REALLY stupid question.

If the amps flowing through a circuit flow over the black (hot) wire, through the load, and then over the white (neutral) wire, and then dissapate to the ground why can we not re-use those amps. If you make the analogy that the amps are like water, it seems to me that we are wasting a lot of water by simply letting it flow into the ground. Is there no way to re-use these amps. Even if, as I assume, less amps are going to the ground (because of the amount the appliance used, as well as the resisitance of the conductors), it appears to me that we should be able to collect these amps somehow, for re-use. Am I really out in left field with this question????

Thanks in advance

JMattero
 
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Old 12-11-05, 07:26 AM
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I guess a good analogy would be that the "amps", or more accurately watts, are not like water being poured into the ground.
The power as wattage is being converted into another form of energy. The electrical energy is being changed into light, heat or motion. It's not as if the power were still there but being dumped to ground.

Is this sort of clear?
 
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Old 12-11-05, 07:29 AM
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They are not being dumped into the ground. They are returning to the generator via the neutral wire.
 
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Old 12-11-05, 07:34 AM
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Oh!!! I thought that once the amps got back to the panel, the path of least resistance was to the ground, either via the ground rod, or the bonding to the water pipes. Are you saying that the path they take is back out of the house and up the pole to the utility company's lines, and then back to the utility company? Thanks.
 
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Old 12-11-05, 07:41 AM
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Originally Posted by Speedy Petey
I guess a good analogy would be that the "amps", or more accurately watts, are not like water being poured into the ground.
The power as wattage is being converted into another form of energy. The electrical energy is being changed into light, heat or motion. It's not as if the power were still there but being dumped to ground.

Is this sort of clear?

Petey - I realize that the load (lights, appliances, etc) are using some of the amps (measured in watts) in whatever job they are performing (lighting the house, spinning a motor, etc). However, in the "jumping the neutral" discussion, it was stated many many times, that some of the amps returned to the panel via the neutral, and that was why it was an insulated conductor, and also why jumping it would potentially electrify the grounding (bare) conductor. Therefore, my question was why are we wasting those amps by dumping them into the ground, rather than recycling them to do useful work again.

If, as you say, ALL of the amps are used by the load, then why aould there be any amps in the neutral wire?

I am simply trying to deepen my understanding, since as a DIYer, I do most of my own electrical work.

Thanks.
 
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Old 12-11-05, 08:41 AM
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The voltage is the "pressure", the amps is the "flowrate" and the wattage is a measure of the total energy consumed by a device. The analogy would be using water pressure to turn a turbine to do some work. The water pressure drops after going through the turbine. If you tried to attach another turbine downstream, it would also turn, but much slower, and the first turbine would turn more slowly because now there is resistance to the flow of water downstream of it.
You could attach another light or device downstream of your first one, but now you are adding more resistance to the flow of electrons, and at a lower voltage. Thus both devices that are connected in series will not work as well as when they are the only thing on a circuit, if they would work at all with the reduced voltage.
From a physics point of view, if you have 120 volts from a wire to ground (which is the "potential" energy), every item (that has a resistance) that you add in series to that circuit will share that voltage such that the voltage will drop across each device, proportional to its resistance. For water, you are starting with 60 or so psi of pressure, then think about adding devices in series as above.
Energy can neither be created nor destroyed, only converted (including from/to matter, as in E=MC^2). What we are doing with the water and electicity is converting from one form of energy to another.
 
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Old 12-11-05, 08:54 AM
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Originally Posted by fixitron

Energy can neither be created nor destroyed, only converted (including from/to matter, as in E=MC^2). What we are doing with the water and electicity is converting from one form of energy to another.
Fixitron:
I understand all of what you have said. However, I do not think it answers the question. Yes, I agree that there will be fewer electrons (ie fewer amps) going back to the ground in relation to the number that came from the power company (due to the work performed by the load device), but why are we simply letting them go back in to the ground, wasted, rather than sending them back to the power company to be included in the another persons electrical supply? Currently we use one type of potential energy (oil. coal, etc) to create another type of energy (electricity), so I realize we are not creating anything. It just seems to me that we are wasting some amount of amps that we have spent a lot of money on converting from another fuel. Why?
 
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Old 12-11-05, 10:14 AM
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Amps is the flowrate and, coupled with the voltage (or pressure) is a measure of the work done. The electrons flow at a rate (the amps) to do the work at a given pressure (the volts). Only enough electrons flow to do the work required, because the only path for the electrons is through a device. Think of the electrons that are leaving the device as being at "ground potential" or having the same energy as all of the other electrons in the ground. The voltage on the neutral wire is zero, in relation to ground. There is no energy left. The device took what energy it needed from the electrons that flowed through it. The more energy the device requires, the greater the flowrate (amps) of electrons needed for a given presssure (volts). If we add another device in series, downstream, that second device will also require a certain flowrate (amps) of electrons to do its thing, but it will have to share the pressure with the first device. Thus the pressure going into the second device will be less than going into the first device but still greater than the voltage to ground. The pressure (voltage) drop across each device will be proportional to its resistance.
Think of the generator from the power company as a big pump. It is pushing electrons down the wire (using magnets). When the electrons do work in a device, they give up their energy to the device and then flow back to earth. Very much like a water pump pumping water under pressure. A turbine does not use the water, but rather the energy of the water. The water goes back to the earth and eventually back to the pump.
These analogies are a bit simplified as to the physics, but I hope they paint a clearer picture.
 
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Old 12-11-05, 02:35 PM
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From a different angle.
It is important to remember what was mentioned in an earlier response, the current is returning to its source. As it returns, it takes all paths, some of which have lower resistance, and will carry more of the current. When the current is returning on the neutral, it is seeking the neutral that created the voltage and current (its source), so it will mostly travel on the neutral wire back to the transformer outside, but a small amount will travel through the neutral to ground bond at the main disconnect and attempt to go through the dirt back to the transformer. Dirt is not a very good conductor, so an overwhelming portion of the current will travel on the neutral back to the transformer.
That current on the neutral still has the ability to perform work, as it fights the resistance of the neutral wire back to the transformer, it still heats the neutral conductor. There just isn't enough voltage at that point to perform significant work to recycle the current as was requested. The voltage is very small on the neutral relative to ground, so not much power to work from.
 
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Old 12-11-05, 03:04 PM
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First of all, the terms "amps" and "watts" are rates. They aren't anything physical. They are rates, like miles per hour.

What's really flowing is electrons. And they don't get used up. The same number of them return to the power company as the power company sent out.

The power company takes electrons, feeds them energy, and sends them out full of pep. When they flow through your light bulb, they work hard and get very tired. Then they have just barely enough energy to limp back to the power company. The power company then feeds them new energy, and sends them back out again.

So we are, in fact, reusing the electrons. But we have to feed them again before they have enough energy to come back out to your house and do some more work for you.
 
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Old 12-11-05, 04:05 PM
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John, that is one of the best analogies I have heard.

I humbly admit I am not as up on theory as many of my peers. This explanation make this very clear to the DIY or layperson.
 
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Old 12-11-05, 04:30 PM
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Current flow requires complete circuit::water does not ( long post)

We must be careful of terminlolfy when comparing apples to oranges. Water gas mass, and when a force is applied, such as gravity, the water will tend to move. Water in a pipe sloped down hill will move. There is no need or force to cause the water to move "back where it came from", except it will flow into the earth if allowed, with gravity still involved.


Electrical current flow is different. The moving force in NOT gravity. It is an electromotive force caused as a result in one point in the circuit having an excess of electrons. EMF can be caused by chemical reaction, as in batteries, or by the MOVEMENT of a conductor through a magnetic field, as happens in generators. Electrons will NOT "fall out of a pipe" by gravity. They do not flow through air. They WILL move through an electrically conductive material, such as wire. The electromotive force from the battery or generator "pushes" the electrons. The RESISTANCE of the wire and the load ( light bulb, etc) opposes the movement. In comes Ohms law which tells us how many amps will flow. Other laws or calculations tell us how much work is done either as heat, light, or movement ( motor HP). Potential energy of the electromotive force is converted to these other forms of energy.

Note that the important consideration here is that water is free to move anywhere and in any direction through pipes, through air, across the ground, etc. confined only by physical barriers and the laws of gravity. The electrons MUST move through a conductor, and must move through a complete current path back to the source. If X amps are to move out of one pole of a battery, or one pole of a generator, an identical X amps must flow into the other pole. This is because the EMF and the current flow thru the source is taking place at the level of EXCESS electrons on molecules of the material. Explaining the physics is beyond me, but to understand electricity you must accept the principle that for even one electron to leave the source, one electron must flow through the circuit and be available at the other pole of the source.

For purposes of this discussion, water has mass, which is why it obeys the laws of gravity:: Electrons do not have mass. We consult the periodic table of elements to understand electron behaviour.


Someone in this thread kept repeating that "amps are returned to the ground, wasted". NOTHING COULD BE FURTHER FROM THE TRUTH. In normal operation NO CURRENT FLOWS TO GROUND. Current is flowing in the secondary of your street transformer. NO PART OF THAT is connected to ground at the street. There are 240 volts potential across the two hot leads. This powers your stove, water heater , dryer, etc. Because it was felt that 240 was a little high for safety of simple loads like lights, toasters, etc. we also divide the transformer by connecting a THIRD wire at the center of the secondary. The voltage between either end pole and the center will be 120 volts. STILL no need for any part of this to be connected to ground. BUT, safety enters in. It happens in electrical equipment that a frayed wire or whatever causes the toaster case, or the metal top of the oven, etc. to be energized by the voltage. Now we have the possibility of a person becoming part of the current path. So, it was decided that one side of the 120 volt source should be connected to GROUND at the house entrance. This wire is now called the neutral. It is called neutral because if all the amps flowing are to 240 volt loads, Zero current would ever flow in that neutral wire. And to the extent that each of the 120 volt legs have approximately equal current flowing, the current in the neutral is still approximately zero, but in real world is not exactly zero.

Even though the neutral wire is connected to ground at the house entrance for safety purposes, no current normally would ever flow into ground . It goes out that wire back to the transformer at the street.

Ohms law explains why at a receptacle in your house or at a load such as lights, washing machine, whatever, the neutral wire and the grounding wire must be separate wires and never connected together.
 
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Old 12-11-05, 04:30 PM
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Thanks Speedy. I just made that explanation up on the spot. But I like it too.

In slightly more technical terms, once you feed an electron a lot of energy, it starts to vibrate very fast. It's that frantic vibration that conveys energy. Once the electron has released its energy (in the form of heat or light or motion), it is vibrating much less. A measure of how much energy an electron has is called "voltage". Another word for voltage is "potential". An electron at a higher voltage has more potential for doing work.

Just as another note, the electron really doesn't travel all the way from the power company to your house. In fact, an individual electron moves pretty slowly. But the high-energy electron's vibrations convey energy to the next electron in the wire, which in turn conveys it to the next and so forth. So the energy travels at about 5/8 the speed of light through the wire, but the individual electrons go much, much, much more slowly.
 
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Old 12-11-05, 05:00 PM
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And just throw some more confusion into the fray, Most of the power does not return on the neutral. It returns on the other leg of your service as power that is 180 out of phase with the other leg.

Actually this is AC power is coming and going at the same time. Ony DC comes on one line and goes on the other.
 
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Old 12-11-05, 05:54 PM
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For purposes of this discussion, water has mass, which is why it obeys the laws of gravity:: Electrons do not have mass. We consult the periodic table of elements to understand electron behaviour.

For purposes of this discussion, we don't care that water has mass. I used water as an analogy because it is something that we are familiar with. If a contributor does not understand why we cannot "re-use those amps" then the answer to that contributor should be in a form that they can understand.

BTW, electrons do have mass: 9.10938188 10-28 grams; and electricity does not need a conductor: lightning;
 
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Old 12-11-05, 08:17 PM
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FOR PURPOSES of discussion, I was rounding off the 10 to the -28 grams.

Electricity ALWAYS needs a conductor. Air is a fairly good insulator at voltages less than 46 gazillion, or whatever lightning is. But when the voltage is high enough, the air molecules ionize and electrons flow. And in a sense, it is a complete circuit. Through various mechanisms, electrons flow gradually up into the clouds and a static charge builds up, just waiting for that strike which will return them to earth!
 
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Old 12-11-05, 08:30 PM
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I'm trying to keep this basic for the DIY.

The AMPS is a measurement of load. that is reflected back to the power grid.
The more load the consumer adds to the power grid, slows down the generator and it cost more to keep the generator running at the required speed.


Watts is a more accurate measurement of the actual cost to produce electricity.

------------------------------------------------
Lets say you driving a car up hill, the hill is 50 amps in height.
your car has to generate more power to get over the hill that is loading your car down.
 
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Old 12-11-05, 11:49 PM
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To add to the other explanations, without using analogies.

Electrical potential, energy, is measured in volts.
Electrical current, the flow of electrons, is measured in amps.
Electrical power, volts x amps, is measured in watts.
An electrical load consumes power.

There can be voltage at an outlet, but without a load no power is used. Connect a 1500 watt load and it will draw 12.5 amps at 120 volts (120 volts x 12.5 amps = 1500 watts). The current (amps) drawn by the load is determined by the power consumed by the load. There is no leftover power, a load only draws what it uses. Anything that offers resistance in the circuit is part of the load and consumes power, this includes the wire. The power consumed by the wire is given off as heat.

To complete a circuit current must leave the source, supply the load and return to the source, it does not go to the earth. The purpose of earth grounding is to dissipate voltage spikes from lighting or high voltage lines and to provide a stable reference, it is primarily a safety measure.
 
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Old 12-12-05, 05:10 AM
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To all of you ... thank you very much. I think now understand. The analogies used make it very clear to me. Again, this is a great resource for us novices.
 
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Old 12-12-05, 02:27 PM
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Under the heading of "beating a dead horse"....

The water analogy still works if you consider that the well will eventually go dry if water does not return to it.

Perhaps a better way to look at it would be a closed loop system like an air conditioning system. The compressor pressurizes the freon, this pressure is dropped across the evaporator coil (work done) and the low pressure freon returns to the compressor to start all over again.

Electricity returns to its source, which in the case of most homes is the transformer on the pole. Whatever leaves on one bushing returns through the others. Ground really doesn't have anything to do with it since, if the transformer was totally isolated from ground (on the secondary side), it would still work.

(Before anybody comes unglued, the "grounds don't have anything to do with it" remark was strictly made in terms of transformer theory. I'm not implying anything here as to code, safety, or otherwise. Removing or otherwise altering a ground without knowing what you are doing can be fatal.)

Electricity doesn't flow in the sense of water or freon. Think of a perfectly straight line of billiard balls. Hit the closest one to you, and the one at the other end moves. On the other half of the cycle (AC current) the action reverses. The electrons basically shuffle back and forth.
 
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