No, YOU check the NEC; you missed something. I already know what it says. Where you went off track was in failing to mention that such a situation can ONLY exist IF it is marked! There are also restrictions on HOW the outlet can be so marked, and I highly doubt that you could get ANY inspector to accept an entire domain wired that way. Your advice sounded to the contrary. If you don't know about the marking rules, check your NEC. And then check your locals. You must meet the more stringent of the two (or three, or four depending on where you live)! NEC is only a minimum requirement in the event of no other coverage. Any local code can exceed but not decede, the NEC. Almost all do.
It seems like you mentioned NY? Hell in this state, you can hardly put water in a toilet if there's an outlet within a hundred feet! It's union's paradise!
Now, if you also go to your local code enforcement, you are highly likely in most localities to find that you would NOT be allowed to use that wiring method.
I'm sorry, but there can be no debate of a subject such as this in the vacuum of one short section of the overall code. As in any technical regulation, the entire context of all related sections and paras must be considered. Everything here is true: but it is not in complete context without the remaining relevant components of the regulation. To be complete, every relevant section/para must be considered. Then, and probably more importantly, local codes must be considered; the NEC is only a starting point and a good reference. It is not the final word as it may (and often is) much more lenient than local codes. You cannot wire simply to the NEC.
NO, the idea is that it allowed them to "grandfather" in old buildings where current regulations would create a severe hardship. You would not get a permet to use this method on new construction.
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.
Pop it is very specific that this is only to "replace" an existing receptacle where an equipment grounding path is not present. If you are adding a new circuit it must be with a grounded wiring method.
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.
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.
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.
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.
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.
Notice that part up there that I just underlined? I said it is supposed to be marked. I also said, in a part you snipped out, that I would rewire the whole thing if it were me.
NEC allows it when replacing old recepticles, no question. Now, local laws can be more strict, but I don't know where the OP is or what his local rules might or might not be. And of course, the local inspector is the final authority.
|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.
| And of course, the local inspector |is the final authority.
Unfortunately, so true.
I added a laundry/sewing room and garage/workshop to my house. Because the laundry was a long way from the primary cooling system (dual evaporative/refrigerated), even though I tapped into the supply duct, I didn't expect much flow. Since I was also adding an evaporative cooler to the garage, I drew up plans that included a supplemental cooling duct from the garage into the laundry. To minimize the run, I compromised the location of the cooler as far as the garage was concerned.
The plans were approved by the plans examiners, and the installed ductwork was approved by the mechanical field inspector. During the final framing inspection, the inspector (another one) told my wife (I was still working at the time) that having a duct from a garage into a living space was against code and I would have to remove it. He in essence voided the previous inspection. He also convinced SWMBO that this was a huge fire hazard and we were all going to die.
I went back to the plans examiners with this info and they said (quote) "Bull shit."
I appealed to the head of the inspection department and he said that he would never overrule one of his field inspectors because, "They are there in the field, I am here behind a desk, so I have to trust their judgement."
Rather than fighting city hall and SWMBO, I removed the duct.
For the sake of discussion, Most of this post is true. However there are some statements that I do not totally agree with in opinion.
Any path for an electric potential to be transferred to a person be it metal, water or otherwise is a danger.
Neutrals are current carrying conductors. A poor or open connection can induce up to the full potential voltage on it.
Neutrals are bonded to ground at the service to insure incidental voltages induced in any circuit have a path to ground and not transferred to all the wiring. ( Lightning strikes to a service or other conductor as an example.)
In my experience, overheated connection failures are about 80% in neutrals. Even on grounded device plugs. Never knew why....
The safety codes and rules are determined by tradesmen, fire officials, engineers and insurance companies. People directly involved. The government only tries to enforce them.
In many this was done intentionally as one supply wire was deliberately connected to the 'isolated' chassis.
The current demand on a device would not determine an overload condition from a single fault unless it was grounded with a separate conductor. Burning out of the fault would disconnect the fault. Generally greatly overloaded windings will cause insulation failure and short circuit within the winding, draw excess current and more heating, also possibly causing a ground fault, eventually destroying continuity of the windings stopping its operation while still allowing that fault connection to an ungrounded device.
I would welcome any corrections if I appear to be mistaken or misinformed.
Oops. Instant fire code violation. There are reasons that the garage must (per NFPA codes) have:
1) 5/8" or thicker fire-rated drywall between garage and living areas. 2) Fire-rated, self-closing door(s) between living areas and garage and 3) No openings between garage and living areas, especially ductwork which can carry both fire and fumes from the garage into the living areas.
Look at the premise here. I said NEUTRAL FAULT to begin with. A small device would work fine because it wouldn't be drawing enough current to cause serious drop across the neutral fault. If a serious fault then developed in the DEVICE, lots of current would flow, possibly burning open the neutral fault and leaving the device case hot.
Maybe I should have separated the faults more clearly.
|>| And of course, the local inspector |>|is the final authority. |>
|>
|>Unfortunately, so true. |>
|>I added a laundry/sewing room and garage/workshop to my house. |>Because the laundry was a long way from the primary cooling system |>(dual evaporative/refrigerated), even though I tapped into the supply |>duct, I didn't expect much flow. Since I was also adding an |>evaporative cooler to the garage, I drew up plans that included a |>supplemental cooling duct from the garage into the laundry. To | |Oops. Instant fire code violation. There are reasons that the garage |must (per NFPA codes) have: | | 1) 5/8" or thicker fire-rated drywall between garage and | living areas.
Done. 5/8 FC on the garage side, 3/4" (1/2 + 1/4) on the house side.
| 2) Fire-rated, self-closing door(s) between living areas and garage and
Done.
| 3) No openings between garage and living areas, especially ductwork | which can carry both fire and fumes from the garage into the living | areas.
Not quite what I was told. I should have added that the SOB inspector would have allowed thicker sheet metal ductwork and a fire operated damper on the laundry side. This was way too much hassle and expense for the limited use I would have made of it.
My main bitch was that I wasted a coupla hundred bucks on sheetmetal and compromised the cooling in the shop by not optimally locating the cooler because of the screwed up inspection department.
I should have just bribed them like the developers do and been done with it.
Your tale reminds me of my first supervisor, a brilliant engineer who designed and built his own home.
The electrical distribution system was a marvel to observe. It included the early vintage low voltage control.
When it was time for the electrical inspection before things could be finished, my supervisor took the day off and made arrangements to meet the electrical inspector to be on site to answer any questions he may have.
A point of reference, at this point in time, unless it was knob and tube, a union electrician would not wire a house.
This was not a knob and tube job since my supervisor did the work.
This obviously raised a red flag, but so be it.
As the story was related to me, my supervisor so totally overwhelmed the inspector with information that it was unnecessary to baffle him with bullshit.
(He had that way about him)
After about 20 minutes, inspector signed off on the job.
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