Semi OT Electrical Question

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I suppose I could post all of article 406 but that is the only relevant part. Certainly a local AHJ can spin this any way he likes but if you are in a state like Florida that has eliminated all local rules as part of a unified state building code and that code accepts the NEC, unaltered that is all there is to say about the subject. You CAN replace an ungrounded receptacle with a GFCI receptacle (or use a GFCI breaker) and all down stream receptacles can be of the grounding type ... as long as your AHJ follows the NEC. Your mileage may vary if you are in a locality that does not accept the NEC and there is a very good chance this doesn't apply outside of the US. People in Europe don't use GFCIs, they have an RCD.
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Neutrals although grounded at the service are not grounds. Reason being that any voltage drop across conductors is halved in the neutral. ( There are exceptions ) This can be from other loads connected to that neutral. Therefore a neutral can carry a voltage potential at the outlet. NEC now requires any 2 wire outlets not having a ground and being replaced, be done so with GFCIs. This does not ground the device connected but does offer protection from any fault that results in a more than a 5 milliamp difference between the conductors or current detected in the grounded conductor of the device fitted with a 3 prong plug. A separate ground wire is preferred.
--
Chipper Wood

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Welll, let's look at this. I'm not addressing code, or what you should do, just the facts.
Danger arises when there is an electrical fault (leakage) from the hot wire or motor winding, etc., of a device to its metallic case. Think electric drill with an insulation failure in the motor winding. For discussion, let's say the case is "connected" to the 120V hot wire. This device will work fine, but you'll be holding the 120V hot in your hand. Even that is fine, UNTIL you touch a "ground", like a water pipe or the case of a "grounded" appliance. At that point, YOU are a current carrying conductor and you will get a healthy (poor choice of word) ZAP. If you are really holding onto things, there is continuing current flow from arm to arm, about the worst way to get it, since it goes by your heart.
NOW, there are some errors in some messages. The third wire "ground" is called that because it doesn't carry current. It is the same size as the others so it can carry enough current to trip the breaker involved when a fault occurs. It's there to suck up the fault current IF the neutral wire opens for some reason. BUT, the neutral is the same size wire and connected to the ground at the panel. If it and its connections are good, it can do the same thing. This is the government helping us by demanding a redundant ground path.
Yes, there IS current in the neutral and yes, it can be above ground by a small amount (couple volts maybe) if high currents are flowing, BUT never enough to be harmful. Problems arise if the neutral is not well connected to ground at the box.. I've NEVER seen this happen in my 62 years, but I HAVE seen a commercial electrician switch hot and ground, making a bunch of equipment cases 120V hot! Imagine the spark when I connected a signal cable from this equipment to something else that was plugged into an outlet that was properly wired! Thank heavens I didn't pick up the grounded device while holding the metal connector on the cable!
At first thought, you might ask why not just connect neutral to the metal tool case and be done with it. That would work, AS LONG as the outlets and plugs were properly polarized (different width prongs) and connected. Unfortunately, old plugs were not polarized and newer ones can be miswired.
Remember when "double insulated" tools were the rage? That was an intermediate stage of development during which two insulation systems were used. One was the regular motor insulation and the other was the plastic case of the tool. This is MUCH better than the two wire metal tool.
Most cheap table radios with tubes had no transformer and could easily get their chassis hot to ground. In this case, the user was protected only by the case and knobs!
If you followed the above, you can see the temptation to use the neutral as a ground. In fact, it would work fine and be safe, UNTIL you had a neutral wire fault, putting your device above ground and making it very dangerous! The GFI outlet is the right answer, unless you can pull new wire.
It should be said here that a device needing considerable power plugged into an outlet with a serious neutral fault would not work properly, because of the voltage drop across the fault, so you might have some warning. A device that drew very little current might work well, however, since the drop would be small, but then a fault could occur to cause more current to flow, burning out the fault and leaving the case hot and the device seemingly off. Bad News!
I'd try to get good hookups in kitchens and laundry areas, but your bedlamp and table radio don't have many dangers, partly because they are not near grounded metal, usually. Same for TVs, etc. A shop with a damp dirt floor needs protection, especially if you are barefooted. The hand to hand shock is the most likely and most dangerous. The hand to foot shock tends to be mitigated by non conductive shoes and dry floors.
Shocks in your left arm are more dangerous than in your right, because of heart nerve location.
Let me know if anything above is misstated or confusing.
Wilson

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What you said is reasonable EXCEPT
The electrical code is extremely conservative, but that allows a lot of us to be still be alive and our houses still standing after doing dumb things. Since we will continue to do dumb things, it is best to leave the redundency there.
Houses existed long before grounds were mandated, and continue to exist; but a separate ground is a redundency that significantly increases safety. My dryer has no ground (technically, practically it has no neutral) so 7.5a is available to any one touching bare metal on it. No one has been hurt, in fact maybe no one has been hurt on the millions of similar dryers, but wouldn't it be nicer to eliminate the possibility by separating the ground and neutral?
Probably the worst aspect of the OP's idea is that a user would have no idea it was done, and would think the grounded conductor really was a grounded conductor rather than a grounding conductor (yes, those are the correct names). If he then does something dumb, there is no safety net.
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That exemption in the code (dryers and ranges) started in WWII to save copper. A couple code cycles ago the NFPA decided the war was finally over and they made these circuits conform to the rest of article 250 with a separate ground and neutral. You will now see 4 prong receptacles being installed there. I suppose the reason we never piled up bodies is because these were 30-50a circuits with very small 120v loads, if one was there at all.
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On 07 Apr 2004 14:46:11 GMT, snipped-for-privacy@aol.com (Greg) wrote:
|>My |>dryer has no ground (technically, practically it has no neutral) | |That exemption in the code (dryers and ranges) started in WWII to save copper. |A couple code cycles ago the NFPA decided the war was finally over and they |made these circuits conform to the rest of article 250 with a separate ground |and neutral. You will now see 4 prong receptacles being installed there. |I suppose the reason we never piled up bodies is because these were 30-50a |circuits with very small 120v loads, if one was there at all.
The motors and light bulbs were 120V loads, making the currents in the two legs unequal and the neutral a current carrying conductor. Furthermore, a fault in the motor and an open neutral and you have a big metal box at 120V in a wet location. Pure lunacy.
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but
is
Consider the electrical devices used in the average home. Most would be relatively safe without grounding. A small point on your skin generally has a resistance of about 10,000 ohms. touching a 120 v. connection would draw only about 1/10 of an amp. in current if you were also in contact with a grounded item. Translated, that's about 1 watt of power divided across 4 to 5 feet of ones body. It would cause a definite reaction, but no damage. Not being in contact with a ground on a wooden floor, It might not even be detectable. However a firm grip on a faulty all metal drill handle not properly grounded and standing on damp grass, This could be a lethal situation as the trigger switch is pulled.
Simple lamps have the possibility to become connected to the outer socket. There is usually only a paper sleeve separating the metal case from the screw shell. In a few years and using over 60 watt lamps the paper all but disintegrates. This is almost never detected by the user.
Insurance companies reserve the right to compensation or denial of claims resulting from willful or deliberate negligence. Everything can become defective over time. Normally a faulty deteriorated electrical connection inside a wall box is not negligent. Pennies behind fuses or a frayed or otherwise defective extension cord used even temporarily across a floor if proven to be an accident cause could be reason to deny a claim.
--
Chipper Wood

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Chipper Wood wrote:

Actually, this amount of current is far from harmless and may be fatal. See <http://www.cdc.gov/niosh/docs/2002-123/2002-123b.html , <http://www.tpub.com/content/fc/14098/css/14098_34.htm , and <http://www.physics.ohio-state.edu/~p616/safety/fatal_current.html .
--
--
Steve

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Steve, Using the first site you posted, Between 5 and 100 milliamps is what I was referring to. Milli as in millennium = 1/1000 100/1000 = 1/10 amp. This will get your attention and cause a reflex. From experience, 277 v. is about 2 1/2 times this amount and is definitely painful at just a touch. Multiply the contact by the area of holding a metal device such as wire strippers firmly and at 120 v. there is a disabling or lethal current present. IMHO, There is nothing about contact with household electric current that can be considered 'harmless' and I hope that no one derived that conclusion from what I wrote.
--
Chipper Wood

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John,
A 2 conductor system can be converted to a 3 conductor if done properly. Call in a professional if you don't know how.
Done correctly, a GFCI can be used in a 2 conductor system. Adding a GFCI outlet to the circuit makes the circuit safe for you. But it doesn't make it safe for your equipment - you need a ground to make surge suppressors or line filters effective. The NEC requires that three prong receptacles without ground that are protected by GFCI must be labelled as such.
Any existing wiring must meet or exceed any local codes and/or the National Electric Code (NEC) that were in effect at time of installation. Any new wiring, including remodeling work, must meet or exceed the current local and/or NEC codes . The 2002 is the current version NEC, but the 2005 NEC code book is scheduled to be released in October, 2004. Also, if you do major work, you may be required to upgrade certain existing portions or all of your system. Check with your local electrical inspector.
If you are worried about a fire, call/hire an electrician. Remember insurance won't pay if faulty wiring is found to be the cause.
Randy

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Randy A writes:

Not necessarily true. State Farm paid off on my fire last year even though the odds were about even between faulty wiring and a sump pump motor wiring fault. Further checking could probably have identified the exact source, but the fire inspector stated the sump pump, with no specifics, was at fault, so they paid. If you have an insurance company that tries to weasel every claim, you're in bad shape to begin with because there is always an "it" that isn't dotted and a "t" that isn't crossed. Time to change companies.
Charlie Self "It is not strange... to mistake change for progress." Millard Fillmore
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"John Moorhead" writes:

hot
NO ! !

NO ! !

grounds
Agreed.
NO ! !

You need to find a qualified electrical contractor who specializes in residential re-wire jobs.
Up front, this one won't be cheap.
My guess is all the existing wiring is loom, knob and tube which just makes the job more difficult.
HTH
--
Lew

S/A: Challenge, The Bullet Proof Boat, (Under Construction in the Southland)
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The legal option is simply using the GFCI outlets and putting the sticker on that says ground is not there. It won't help the surge protector for your electronics but it will mitigate the danger of electrocution. A better fix is to get a ground wire up there but that may be out of your budget..
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Is the wiring 'BX' (metal sheath)? If it is, check if you have 120 V between the Hot and the metal box. If there is, the ground is being carried by the cable sheath. What you will want to do is to attach a ground strap to the box, then to the outlet.
If there is no ground present, then follow the other advice given.
--
Al Reid

"It ain't what you don't know that gets you into trouble. It's what you know
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Replacing non-grounded outlets with grounded outlets is a violation of most electrical codes and hence could impact your insurance if problems arise.
Don Dando

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Welll, let's look at this. I'm not addressing code, or what you should do, just the facts.
Danger arises when there is an electrical fault (leakage) from the hot wire or motor winding, etc., of a device to its metallic case. Think electric drill with an insulation failure in the motor winding. For discussion, let's say the case is "connected" to the 120V hot wire. This device will work fine, but you'll be holding the 120V hot in your hand. Even that is fine, UNTIL you touch a "ground", like a water pipe or the case of a "grounded" appliance. At that point, YOU are a current carrying conductor and you will get a healthy (poor choice of word) ZAP. If you are really holding onto things, there is continuing current flow from arm to arm, about the worst way to get it, since it goes by your heart.
NOW, there are some errors in some messages. The third wire "ground" is called that because it doesn't carry current. It is the same size as the others so it can carry enough current to trip the breaker involved when a fault occurs. It's there to suck up the fault current IF the neutral wire opens for some reason. BUT, the neutral is the same size wire and connected to the ground at the panel. If it and its connections are good, it can do the same thing. This is the government helping us by demanding a redundant ground path.
Yes, there IS current in the neutral and yes, it can be above ground by a small amount (couple volts maybe) if high currents are flowing, BUT never enough to be harmful. Problems arise if the neutral is not well connected to ground at the box.. I've NEVER seen this happen in my 62 years, but I HAVE seen a commercial electrician switch hot and ground, making a bunch of equipment cases 120V hot! Imagine the spark when I connected a signal cable from this equipment to something else that was plugged into an outlet that was properly wired! Thank heavens I didn't pick up the grounded device while holding the metal connector on the cable!
At first thought, you might ask why not just connect neutral to the metal tool case and be done with it. That would work, AS LONG as the outlets and plugs were properly polarized (different width prongs) and connected. Unfortunately, old plugs were not polarized and newer ones can be miswired.
Remember when "double insulated" tools were the rage? That was an intermediate stage of development during which two insulation systems were used. One was the regular motor insulation and the other was the plastic case of the tool. This is MUCH better than the two wire metal tool.
Most cheap table radios with tubes had no transformer and could easily get their chassis hot to ground. In this case, the user was protected only by the case and knobs!
If you followed the above, you can see the temptation to use the neutral as a ground. In fact, it would work fine and be safe, UNTIL you had a neutral wire fault, putting your device above ground and making it very dangerous! The GFI outlet is the right answer, unless you can pull new wire.
It should be said here that a device needing considerable power plugged into an outlet with a serious neutral fault would not work properly, because of the voltage drop across the fault, so you might have some warning. A device that drew very little current might work well, however, since the drop would be small, but then a fault could occur to cause more current to flow, burning out the fault and leaving the case hot and the device seemingly off. Bad News!
I'd try to get good hookups in kitchens and laundry areas, but your bedlamp and table radio don't have many dangers, partly because they are not near grounded metal, usually. Same for TVs, etc. A shop with a damp dirt floor needs protection, especially if you are barefooted. The hand to hand shock is the most likely and most dangerous. The hand to foot shock tends to be mitigated by non conductive shoes and dry floors.
Shocks in your left arm are more dangerous than in your right, because of heart nerve location.
Let me know if anything above is misstated or confusing.
Wilson

hot
prong
grounds
terminals
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wrote:
|Welll, let's look at this. I'm not addressing code, or what you should do, |just the facts. | |Danger arises when there is an electrical fault (leakage) from the hot wire |or motor winding, etc., of a device to its metallic case. Think electric |drill with an insulation failure in the motor winding. For discussion, |let's say the case is "connected" to the 120V hot wire. This device will |work fine, but you'll be holding the 120V hot in your hand. Even that is |fine, UNTIL you touch a "ground", like a water pipe or the case of a |"grounded" appliance. At that point, YOU are a current carrying conductor |and you will get a healthy (poor choice of word) ZAP. If you are really |holding onto things, there is continuing current flow from arm to arm, about |the worst way to get it, since it goes by your heart.
Exactly. Let me offer this personal example.
In my youth I worked in an automotive machine shop. The shop was in an old building where all of the 110V (standard V in that era) wiring was two-wire, i.e. no grounding conductor.
We installed an engine balancer and the wiring associated with that equipment was brought up to code so it included some three-wire outlets. I was the only person qualified to run the balancing equipment and the rules were that accessories were to remain at the balancing station and not to be used elsewhere in the shop.
One day I was balancing a crankshaft/flywheel/clutch plate assembly and needed to drill a lightening hole in the clutch plate. The bosses that centered the coil springs had extra material so the process was to use reach through the middle of the spring with a 1/2" drill bit and drill into the boss to take out some weight. Since the assembly was resting horizontally on a set of precision low drag bearings it was necessary to get a real firm grip on it to keep it from turning and to apply the necessary force to drill the hole.
So I grabbed the far side of the ring gear with my left hand, cradled the near side in the crook of my left elbow and with my right hand stuck the drill bit, mounted in a heavy duty B&D or Milwaukee (I forget which) 1/2 drill motor into the hole and pulled the trigger.
The shock I received was the worse I've ever experienced and after my machine shop days I went into EE and between that and ham radio I've been shocked many times. Since I'm still kicking I surmise that the current was below the critical current that can cause fibrillation and the point at which you can't let go.
When I recovered I discovered that some son of a bitch had used the drill motor elsewhere in the shop and when he couldn't plug it in, had cut off the ground pin on the connector.
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Welll, let's look at this. I'm not addressing code, or what you should do, just the facts.
Danger arises when there is an electrical fault (leakage) from the hot wire or motor winding, etc., of a device to its metallic case. Think electric drill with an insulation failure in the motor winding. For discussion, let's say the case is "connected" to the 120V hot wire. This device will work fine, but you'll be holding the 120V hot in your hand. Even that is fine, UNTIL you touch a "ground", like a water pipe or the case of a "grounded" appliance. At that point, YOU are a current carrying conductor and you will get a healthy (poor choice of word) ZAP. If you are really holding onto things, there is continuing current flow from arm to arm, about the worst way to get it, since it goes by your heart.
NOW, there are some errors in some messages. The third wire "ground" is called that because it doesn't carry current. It is the same size as the others so it can carry enough current to trip the breaker involved when a fault occurs. It's there to suck up the fault current IF the neutral wire opens for some reason. BUT, the neutral is the same size wire and connected to the ground at the panel. If it and its connections are good, it can do the same thing. This is the government helping us by demanding a redundant ground path.
Yes, there IS current in the neutral and yes, it can be above ground by a small amount (couple volts maybe) if high currents are flowing, BUT never enough to be harmful. Problems arise if the neutral is not well connected to ground at the box.. I've NEVER seen this happen in my 62 years, but I HAVE seen a commercial electrician switch hot and ground, making a bunch of equipment cases 120V hot! Imagine the spark when I connected a signal cable from this equipment to something else that was plugged into an outlet that was properly wired! Thank heavens I didn't pick up the grounded device while holding the metal connector on the cable!
At first thought, you might ask why not just connect neutral to the metal tool case and be done with it. That would work, AS LONG as the outlets and plugs were properly polarized (different width prongs) and connected. Unfortunately, old plugs were not polarized and newer ones can be miswired.
Remember when "double insulated" tools were the rage? That was an intermediate stage of development during which two insulation systems were used. One was the regular motor insulation and the other was the plastic case of the tool. This is MUCH better than the two wire metal tool.
Most cheap table radios with tubes had no transformer and could easily get their chassis hot to ground. In this case, the user was protected only by the case and knobs!
If you followed the above, you can see the temptation to use the neutral as a ground. In fact, it would work fine and be safe, UNTIL you had a neutral wire fault, putting your device above ground and making it very dangerous! The GFI outlet is the right answer, unless you can pull new wire.
It should be said here that a device needing considerable power plugged into an outlet with a serious neutral fault would not work properly, because of the voltage drop across the fault, so you might have some warning. A device that drew very little current might work well, however, since the drop would be small, but then a fault could occur to cause more current to flow, burning out the fault and leaving the case hot and the device seemingly off. Bad News!
I'd try to get good hookups in kitchens and laundry areas, but your bedlamp and table radio don't have many dangers, partly because they are not near grounded metal, usually. Same for TVs, etc. A shop with a damp dirt floor needs protection, especially if you are barefooted. The hand to hand shock is the most likely and most dangerous. The hand to foot shock tends to be mitigated by non conductive shoes and dry floors.
Shocks in your left arm are more dangerous than in your right, because of heart nerve location.
Let me know if anything above is misstated or confusing.
Wilson

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terminals
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Welll, let's look at this. I'm not addressing code, or what you should do, just the facts.
Danger arises when there is an electrical fault (leakage) from the hot wire or motor winding, etc., of a device to its metallic case. Think electric drill with an insulation failure in the motor winding. For discussion, let's say the case is "connected" to the 120V hot wire. This device will work fine, but you'll be holding the 120V hot in your hand. Even that is fine, UNTIL you touch a "ground", like a water pipe or the case of a "grounded" appliance. At that point, YOU are a current carrying conductor and you will get a healthy (poor choice of word) ZAP. If you are really holding onto things, there is continuing current flow from arm to arm, about the worst way to get it, since it goes by your heart.
NOW, there are some errors in some messages. The third wire "ground" is called that because it doesn't carry current. It is the same size as the others so it can carry enough current to trip the breaker involved when a fault occurs. It's there to suck up the fault current IF the neutral wire opens for some reason. BUT, the neutral is the same size wire and connected to the ground at the panel. If it and its connections are good, it can do the same thing. This is the government helping us by demanding a redundant ground path.
Yes, there IS current in the neutral and yes, it can be above ground by a small amount (couple volts maybe) if high currents are flowing, BUT never enough to be harmful. Problems arise if the neutral is not well connected to ground at the box.. I've NEVER seen this happen in my 62 years, but I HAVE seen a commercial electrician switch hot and ground, making a bunch of equipment cases 120V hot! Imagine the spark when I connected a signal cable from this equipment to something else that was plugged into an outlet that was properly wired! Thank heavens I didn't pick up the grounded device while holding the metal connector on the cable!
At first thought, you might ask why not just connect neutral to the metal tool case and be done with it. That would work, AS LONG as the outlets and plugs were properly polarized (different width prongs) and connected. Unfortunately, old plugs were not polarized and newer ones can be miswired.
Remember when "double insulated" tools were the rage? That was an intermediate stage of development during which two insulation systems were used. One was the regular motor insulation and the other was the plastic case of the tool. This is MUCH better than the two wire metal tool.
Most cheap table radios with tubes had no transformer and could easily get their chassis hot to ground. In this case, the user was protected only by the case and knobs!
If you followed the above, you can see the temptation to use the neutral as a ground. In fact, it would work fine and be safe, UNTIL you had a neutral wire fault, putting your device above ground and making it very dangerous! The GFI outlet is the right answer, unless you can pull new wire.
It should be said here that a device needing considerable power plugged into an outlet with a serious neutral fault would not work properly, because of the voltage drop across the fault, so you might have some warning. A device that drew very little current might work well, however, since the drop would be small, but then a fault could occur to cause more current to flow, burning out the fault and leaving the case hot and the device seemingly off. Bad News!
I'd try to get good hookups in kitchens and laundry areas, but your bedlamp and table radio don't have many dangers, partly because they are not near grounded metal, usually. Same for TVs, etc. A shop with a damp dirt floor needs protection, especially if you are barefooted. The hand to hand shock is the most likely and most dangerous. The hand to foot shock tends to be mitigated by non conductive shoes and dry floors.
Shocks in your left arm are more dangerous than in your right, because of heart nerve location.
Let me know if anything above is misstated or confusing.
Wilson

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grounds
terminals
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Welll, let's look at this. I'm not addressing code, or what you should do, just the facts.
Danger arises when there is an electrical fault (leakage) from the hot wire or motor winding, etc., of a device to its metallic case. Think electric drill with an insulation failure in the motor winding. For discussion, let's say the case is "connected" to the 120V hot wire. This device will work fine, but you'll be holding the 120V hot in your hand. Even that is fine, UNTIL you touch a "ground", like a water pipe or the case of a "grounded" appliance. At that point, YOU are a current carrying conductor and you will get a healthy (poor choice of word) ZAP. If you are really holding onto things, there is continuing current flow from arm to arm, about the worst way to get it, since it goes by your heart.
NOW, there are some errors in some messages. The third wire "ground" is called that because it doesn't carry current. It is the same size as the others so it can carry enough current to trip the breaker involved when a fault occurs. It's there to suck up the fault current IF the neutral wire opens for some reason. BUT, the neutral is the same size wire and connected to the ground at the panel. If it and its connections are good, it can do the same thing. This is the government helping us by demanding a redundant ground path.
Yes, there IS current in the neutral and yes, it can be above ground by a small amount (couple volts maybe) if high currents are flowing, BUT never enough to be harmful. Problems arise if the neutral is not well connected to ground at the box.. I've NEVER seen this happen in my 62 years, but I HAVE seen a commercial electrician switch hot and ground, making a bunch of equipment cases 120V hot! Imagine the spark when I connected a signal cable from this equipment to something else that was plugged into an outlet that was properly wired! Thank heavens I didn't pick up the grounded device while holding the metal connector on the cable!
At first thought, you might ask why not just connect neutral to the metal tool case and be done with it. That would work, AS LONG as the outlets and plugs were properly polarized (different width prongs) and connected. Unfortunately, old plugs were not polarized and newer ones can be miswired.
Remember when "double insulated" tools were the rage? That was an intermediate stage of development during which two insulation systems were used. One was the regular motor insulation and the other was the plastic case of the tool. This is MUCH better than the two wire metal tool.
Most cheap table radios with tubes had no transformer and could easily get their chassis hot to ground. In this case, the user was protected only by the case and knobs!
If you followed the above, you can see the temptation to use the neutral as a ground. In fact, it would work fine and be safe, UNTIL you had a neutral wire fault, putting your device above ground and making it very dangerous! The GFI outlet is the right answer, unless you can pull new wire.
It should be said here that a device needing considerable power plugged into an outlet with a serious neutral fault would not work properly, because of the voltage drop across the fault, so you might have some warning. A device that drew very little current might work well, however, since the drop would be small, but then a fault could occur to cause more current to flow, burning out the fault and leaving the case hot and the device seemingly off. Bad News!
I'd try to get good hookups in kitchens and laundry areas, but your bedlamp and table radio don't have many dangers, partly because they are not near grounded metal, usually. Same for TVs, etc. A shop with a damp dirt floor needs protection, especially if you are barefooted. The hand to hand shock is the most likely and most dangerous. The hand to foot shock tends to be mitigated by non conductive shoes and dry floors.
Shocks in your left arm are more dangerous than in your right, because of heart nerve location.
Let me know if anything above is misstated or confusing.
Wilson

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