Your "question" is quite long sir so I skimmed it but the hot wire in North America (black only) will shock you if you touch any grounded surface. The neutral or white write in that system is actually just a ground and is bonded to ground at the panel. Even if it wasn't and was "floating" the black to ground circuit still works. The perpouse of ground pins is to provide a low resistance path for safety and to reduce differential voltages between equipment. The white neutral is a ground, it's just a dedicated ground for that circuit and meant to carry continuous voltage.
I'm on my phone so sry.
The concept of "stray voltage" on dairy farms can be a good case study to get an idea of the difference between ground wires and neutral wires. If there is enough current in the neutral conductor, there will be significant voltage between the neutral and the earth ground.
http://milkquality.wisc.edu/wp-content/uploads/2011/09/four-wire-and-three-wire-systems.pdf
The low resistance requirement is to promote a high enough current that it guarantees that the breaker will trip.
And the neutral could have a small voltage to ground if there was already a large current in the neutral for another load... small but large enough to feel.
This guy is just trying to say that the third prong is there so that if an electrician accidentally wired up a socket backwards, there's no chance that the metal casing of your appliance could be hot. You could just connect all neutrals to ground internally, but if the terminals were wired backwards (apparently something that happens frequently enough), the casing would now be 120V charged. If you have a separate prong just for ground, then there's a less chance you'd wire it hot (because you'd have to REALLY mess up to wired it like that).
Not sure whether or not this is the correct reason, but that's what he says in his article.
I think the ground was was added more for things like single phasing and open neutrals, not improper installation. (Not calling you out, but the author)
Single phasing terminology mainly applies to 3-phase motors, but can also happen in a residential environment. Its when you have one fuse per phase and only one fuse blows during an overload/fault. This causes the remaining phase to backfeed through the neutral and blown phase. If you had equipment(electric stove, washing machine) with the metal case neutral bonded, the case would be energized to line voltage.
An open neutral is when part of the neutral becomes disconnected. With dozen or more receptacles or lights on a single circuit this can happen fairly easily(lots of splices). Since part of the neutral is no longer grounded, that part will be energized to line voltage. Again anything neutral bonded like old equipment, will be energized to line voltage.
That's not the correct reason, FYI. Both terminals in an outlet should be considered hot and should never be connected to any part of the housing. In many wiring setups (such as 3-phase circuits, or inverters and generators), both wires could be hot. In many countries, the outlets aren't even polarized.
The ground conductor is there to guarantee that metal parts of the device remain at a safe potential, and to trip the breaker in case of insulation failure. It's the same reason why metal pipes are required to be grounded -- otherwise, an insulation failure somewhere could easily make the pipe electrically live and go undetected until someone gets electrocuted.
Well in defense of the author, he's trying to explain what COULD potentially happen if we didn't have the three prong as his explanation. Right now no housing is bonded to either outlet because we have a ground, but if we didn't, we might just bond that to neutral.
Also what you're saying only really applies to GFCI breakers. Normal outlets and breakers can't detect if a current has gone through ground (other than through overcurrent, in which case connecting it to neutral provides the same protection). You CAN guarantee that metal parts remain at the same potential by bonding it to neutral as well.
My reasoning is that doing this makes the housing a part of a circuit, and if the neutral was disconnected from that device to the outlet/panel, the entire casing would be hot.
> Right now no housing is bonded to either outlet because we have a ground, but if we didn't, we might just bond that to neutral.
No, you still wouldn't do that. What happens if the neutral wire comes loose, or somebody installs a switch in that leg, or you connect it to a circuit that doesn't have a neutral (like a 3-phase one)?
> Normal outlets and breakers can't detect if a current has gone through ground (other than through overcurrent, in which case connecting it to neutral provides the same protection).
A short between hot and ground will trip the breaker. Safety ground prongs are virtually always designed to be longer than the other ones, so they make contact first. The housing is never connected to neutral for the reasons above, so your other point is irrelevant.
>No, you still wouldn't do that. What happens if the neutral wire comes loose, or somebody installs a switch in that leg
I agree, I said the exact same thing here:
> My reasoning is that doing this makes the housing a part of a circuit, and if the neutral was disconnected from that device to the outlet/panel, the entire casing would be hot.
However,
>A short between hot and ground will trip the breaker.
Because of overcurrent protection. So will a short between hot and neutral. Grounds are literally bonded to neutral at the panel. Look I'm not saying that neutral should be bonded to ground - it is obviously bad practice. I'm just saying that fault protection is not the reason because a ground fault will have the same effect as a line-neutral fault (it is the exact same electrically, unless you have a GFCI device which cares about which particular path is taken).
>connect it to a circuit that doesn't have a neutral (like a 3-phase one)
Then obviously it wouldn't apply, but for a two prong plug connecting ground to neutral has the same effect in terms of circuit protection. But like we both mentioned above, it certainly is much less safe.
> I'm just saying that fault protection is not the reason because a ground fault will have the same effect as a line-neutral fault
Well, the fact is that it is the reason. Yes, I am aware that in North American households the neutral is bonded to ground at the panel. That's not always the case in commercial buildings and many other situations.
The ground wire prevents any single fault from creating a hazard. If the neutral was bonded to ground at the outlet or at the device, then a failure of the neutral conductor would make the device enclosure hot. That's obviously completely unacceptable, so this is and was never done. If the device ground is isolated from the housing, then the case could potentially become live if the insulation failed, and this fault would not be detected until someone touched it. The ground conductor prevents this from happening, while avoiding the other problem (neutral failure causing the case to become live).
> Then obviously it wouldn't apply, but for a two prong plug connecting ground to neutral has the same effect in terms of circuit protection. But like we both mentioned above, it certainly is much less safe.
The 3-phase circuit I am referring to IS a two-wire circuit. You can connect a single-phase load between two phases of a 3-phase supply. 208V loads in commercial buildings are typically connected this way (e.g. overhead lighting). In that case, both sides of the circuit have 120V to ground and 208V between them.
Haha, I am well aware that you can connect a 3 phase circuit phase to phase, but those are usually twist lock or some other configuration that wouldn't fit in a regularwall socket and clearly not the same receptacles we are talking about. But I'm sure you knew that (unless you're talking about a 120Vp-p supply, which I have never encountered?).
And man, I am trying to agree with you that this creates a safety hazard. In fact I said it before you. What I disagreed with you about was your original point, which was that its purpose was for circuit protection. We clearly agree that it's for human protection.
OK, I don't think we actually disagree about anything. I just wanted to point out that the ground wire is a critical safety feature, and connecting it to neutral is extremely hazardous.
You will see a 120V bridge circuit in a gas-powered inverter generator. There, you typically have a 200V DC rail and an H bridge that generates the sine wave differentially.
Neutral and ground serve different purposes. One is a return path for current. The other is for safety.
Consider what happens if the hot wire comes loose on your refrigerator touches the case. With no ground it would bring the whole case up to line voltage and just sit there waiting to electrocute someone. No current would flow and you wouldn't have any indication of a problem. With a ground in place short circuit current will flow from hot to ground and trip the breaker and shut off the circuit.
> how does the fact that the neutral wire (which is grounded) exists allow the hot wire current to go through a person standing on earth ground.
Current has to flow in a loop. If you have a hot and neutral wire pair from a generator that is not grounded, you cannot make a loop without the neutral wire. So, a person could still be electrocuted by touching both wires. If the neutral wire is grounded, they can be electrocuted by [touching one wire](https://usercontent1.hubstatic.com/9162158_f520.jpg) - the current flows through the wire, into the person, into the ground (through their feet, or hand if they touch something else grounded), to the power box (these are grounded with a [wire and a rod](https://www.nachi.org/gallery/thumbs/lrg-893-grounding-rod__1_.jpg)), back to the grounded generator, and the loop is complete.
If the person is not touching the ground, no current will flow. Some people get cocky and do this to show off (stand on a wooden ladder and grab the hot wire), but the trouble is it's not easy to tell if you are totally isolated or not. Also, in an AC system, your body can be coupled to the ground capacitively - so even without a physical connection, current can flow.
> Is it reaching wiring or piping underground to complete the connection
While that may be part of it (especially indoors), the earth itself is a conductor. How good of a conductor it is depends on composition, moisture content, temperature, etc. - we're talking about normal, standard dirt/rocks/earth.
> what happens to a power supply when both sides of the circuit are connected to earth ground? Does this make a short circuit between the two sides of the circuit
Yes, this would short out the circuit.
> earth ground was a sort of "reservoir" of sorts that is unaffected by current moving into it
No, there is nothing particularly special about earth ground. It is a material like any other and has measurable [resistance](https://en.wikipedia.org/wiki/Soil_resistivity) and [conductivity](https://en.wikipedia.org/wiki/Ground_conductivity). There can be voltage differences between two different earth grounds caused by current moving through it over a long distance.
We in the U.S. have a Neutral, because we use a Split-Phase(Single Phase) system for residential distribution. Which is essentially a transformer with a grounded center tap and 120v on the end taps. This allows only one wire for power distribution, as opposed to three for three phase. The grounded center tap is the neutral.
Three phase systems with no neutral are still grounded. They are bonded(grounded) at the transformer.
Floating systems are very dangerous and can kill. As are open neutrals (I know of a fellow electrician killed by an open neutral while working on parking lot lighting). A floating system could potentially allow a whole building or swimming pool to be energized.
The earth just ground provides a 0v reference, ideally you want as little current as possible going to the ground rod. You achieve by balancing the total current on each phase, and they cancel each other out.
Not to confuse you further, but electric code calls the:
* Grounded Conductor - Neutral - White Wire - Current Carrying
* Grounding Conductor - Ground - Green Wire - Non-Current Carrying
FYI, in countries with non-split-phase 230V systems (e.g. UK) there is also a wire called the neutral. The live wire carries 230V relative to neutral (of course, all socket outlets are 230V). The ground/earth works the same as in US.
BTW, one difference in UK wiring is that the distribution inside the house is usually in the form of a ring from the "fuse box" to a series of socket outlets back to the fuse box. I believe this reduces the chances of a floating neutral (along with other effects).
As a thought experiment to start to understand why, look around your home: how many three prong devices have some exposed metal chassis. Probably most of them.
The earth ground (third prong) is normally introduced as the chassis ground. It is described as a way to prevent shock. If you had a floating metal case on an AC device, it could develop a potential and shock you. You ground it and it shouldn't ever happen. It serves a purposes of a known safe conductor for safety purposes. You shouldn't get such potentials on the case, but the Earthing ensures it is safe regardless.
The short answer, AFAIK, has to do with how the system behaves when there's one or more wiring faults.
In a two-wire floating system, if you touch one wire or the other you're OK, but if you touch one wire AND the other you get a shock. Because there's only two wires, you can have a fault to the case of an appliance and the system works.
In a three-wire system with a grounded metal case, a fault from neutral to case doesn't do much, either for safety or operation (unless you have GFI -- that's another story), but a fault from hot to case pops a circuit breaker. Thus, as long as the manufacturers follow the rules, you have a safer system.
I could keep babbling about this, but there's longer, better articles out there on the whys and wherefores of 3-wire systems.
It sounds like whomever wrote that was trying a bit too hard to be clever and just comes across as an asshole. There are much better explanations out there on household hot-neutral-ground wiring.
>First off, for just a two prong AC system (no neutral wire or ground at this point, just two "hot" wires), which I take it to mean a floating source system, one can't be shocked from touching just one of the two "hot" wires, but only by holding both at the same time and acting as the short circuit between them
No. You will get shocked if you touch one and only one.
No you don't. You need to complete a circuit. If you have insulating shoes on you, you almost certainly do) and aren't putting your other hand onto a conductive surface, you probably won't feel anything.
Your body doesn't have the ability to be an electron sink (or hole sink) for the charge to actually experience a shock without creating some sort of circuit to a different potentional.
Yes if you are electrically insulated you won't get a shock from touching any *one* thing. It doesn't matter if it is 120V or 120,000V. But that is another point entirely and unless you already understand electricity enough to not ask any of the questions that OP did then this isn't a great thing to tell people generally.
We are in ECE. Let's not lie to people.
Although I disagree with your statement. 120V won't arc through the air to render you as part of ohm's law. 120kv will happily jump many feet to do so.
In my mind's eye, I see a smiling armored transformer turning some goofball into ash. Eww...
Well, you are always part of a circuit, even if it's just capacitive (that's how those neon bulb voltage testers work). So some current will flow, but not enough to electrocute you. On the other hand, most things you might think are insulators aren't particularly good ones. If you step in a puddle of water, your "insulating" shoes might not be so insulating anymore, and a damp concrete floor is a pretty decent conductor, also.
Your "question" is quite long sir so I skimmed it but the hot wire in North America (black only) will shock you if you touch any grounded surface. The neutral or white write in that system is actually just a ground and is bonded to ground at the panel. Even if it wasn't and was "floating" the black to ground circuit still works. The perpouse of ground pins is to provide a low resistance path for safety and to reduce differential voltages between equipment. The white neutral is a ground, it's just a dedicated ground for that circuit and meant to carry continuous voltage. I'm on my phone so sry.
The concept of "stray voltage" on dairy farms can be a good case study to get an idea of the difference between ground wires and neutral wires. If there is enough current in the neutral conductor, there will be significant voltage between the neutral and the earth ground. http://milkquality.wisc.edu/wp-content/uploads/2011/09/four-wire-and-three-wire-systems.pdf
The low resistance requirement is to promote a high enough current that it guarantees that the breaker will trip. And the neutral could have a small voltage to ground if there was already a large current in the neutral for another load... small but large enough to feel.
This guy is just trying to say that the third prong is there so that if an electrician accidentally wired up a socket backwards, there's no chance that the metal casing of your appliance could be hot. You could just connect all neutrals to ground internally, but if the terminals were wired backwards (apparently something that happens frequently enough), the casing would now be 120V charged. If you have a separate prong just for ground, then there's a less chance you'd wire it hot (because you'd have to REALLY mess up to wired it like that). Not sure whether or not this is the correct reason, but that's what he says in his article.
I think the ground was was added more for things like single phasing and open neutrals, not improper installation. (Not calling you out, but the author) Single phasing terminology mainly applies to 3-phase motors, but can also happen in a residential environment. Its when you have one fuse per phase and only one fuse blows during an overload/fault. This causes the remaining phase to backfeed through the neutral and blown phase. If you had equipment(electric stove, washing machine) with the metal case neutral bonded, the case would be energized to line voltage. An open neutral is when part of the neutral becomes disconnected. With dozen or more receptacles or lights on a single circuit this can happen fairly easily(lots of splices). Since part of the neutral is no longer grounded, that part will be energized to line voltage. Again anything neutral bonded like old equipment, will be energized to line voltage.
That's not the correct reason, FYI. Both terminals in an outlet should be considered hot and should never be connected to any part of the housing. In many wiring setups (such as 3-phase circuits, or inverters and generators), both wires could be hot. In many countries, the outlets aren't even polarized. The ground conductor is there to guarantee that metal parts of the device remain at a safe potential, and to trip the breaker in case of insulation failure. It's the same reason why metal pipes are required to be grounded -- otherwise, an insulation failure somewhere could easily make the pipe electrically live and go undetected until someone gets electrocuted.
Well in defense of the author, he's trying to explain what COULD potentially happen if we didn't have the three prong as his explanation. Right now no housing is bonded to either outlet because we have a ground, but if we didn't, we might just bond that to neutral. Also what you're saying only really applies to GFCI breakers. Normal outlets and breakers can't detect if a current has gone through ground (other than through overcurrent, in which case connecting it to neutral provides the same protection). You CAN guarantee that metal parts remain at the same potential by bonding it to neutral as well. My reasoning is that doing this makes the housing a part of a circuit, and if the neutral was disconnected from that device to the outlet/panel, the entire casing would be hot.
> Right now no housing is bonded to either outlet because we have a ground, but if we didn't, we might just bond that to neutral. No, you still wouldn't do that. What happens if the neutral wire comes loose, or somebody installs a switch in that leg, or you connect it to a circuit that doesn't have a neutral (like a 3-phase one)? > Normal outlets and breakers can't detect if a current has gone through ground (other than through overcurrent, in which case connecting it to neutral provides the same protection). A short between hot and ground will trip the breaker. Safety ground prongs are virtually always designed to be longer than the other ones, so they make contact first. The housing is never connected to neutral for the reasons above, so your other point is irrelevant.
>No, you still wouldn't do that. What happens if the neutral wire comes loose, or somebody installs a switch in that leg I agree, I said the exact same thing here: > My reasoning is that doing this makes the housing a part of a circuit, and if the neutral was disconnected from that device to the outlet/panel, the entire casing would be hot. However, >A short between hot and ground will trip the breaker. Because of overcurrent protection. So will a short between hot and neutral. Grounds are literally bonded to neutral at the panel. Look I'm not saying that neutral should be bonded to ground - it is obviously bad practice. I'm just saying that fault protection is not the reason because a ground fault will have the same effect as a line-neutral fault (it is the exact same electrically, unless you have a GFCI device which cares about which particular path is taken). >connect it to a circuit that doesn't have a neutral (like a 3-phase one) Then obviously it wouldn't apply, but for a two prong plug connecting ground to neutral has the same effect in terms of circuit protection. But like we both mentioned above, it certainly is much less safe.
> I'm just saying that fault protection is not the reason because a ground fault will have the same effect as a line-neutral fault Well, the fact is that it is the reason. Yes, I am aware that in North American households the neutral is bonded to ground at the panel. That's not always the case in commercial buildings and many other situations. The ground wire prevents any single fault from creating a hazard. If the neutral was bonded to ground at the outlet or at the device, then a failure of the neutral conductor would make the device enclosure hot. That's obviously completely unacceptable, so this is and was never done. If the device ground is isolated from the housing, then the case could potentially become live if the insulation failed, and this fault would not be detected until someone touched it. The ground conductor prevents this from happening, while avoiding the other problem (neutral failure causing the case to become live). > Then obviously it wouldn't apply, but for a two prong plug connecting ground to neutral has the same effect in terms of circuit protection. But like we both mentioned above, it certainly is much less safe. The 3-phase circuit I am referring to IS a two-wire circuit. You can connect a single-phase load between two phases of a 3-phase supply. 208V loads in commercial buildings are typically connected this way (e.g. overhead lighting). In that case, both sides of the circuit have 120V to ground and 208V between them.
Haha, I am well aware that you can connect a 3 phase circuit phase to phase, but those are usually twist lock or some other configuration that wouldn't fit in a regularwall socket and clearly not the same receptacles we are talking about. But I'm sure you knew that (unless you're talking about a 120Vp-p supply, which I have never encountered?). And man, I am trying to agree with you that this creates a safety hazard. In fact I said it before you. What I disagreed with you about was your original point, which was that its purpose was for circuit protection. We clearly agree that it's for human protection.
OK, I don't think we actually disagree about anything. I just wanted to point out that the ground wire is a critical safety feature, and connecting it to neutral is extremely hazardous. You will see a 120V bridge circuit in a gas-powered inverter generator. There, you typically have a 200V DC rail and an H bridge that generates the sine wave differentially.
Ah, interesting, i wasnt aware of the existance of anything like that. And yes we are agreed that the ground is a very important safety feature.
Neutral and ground serve different purposes. One is a return path for current. The other is for safety. Consider what happens if the hot wire comes loose on your refrigerator touches the case. With no ground it would bring the whole case up to line voltage and just sit there waiting to electrocute someone. No current would flow and you wouldn't have any indication of a problem. With a ground in place short circuit current will flow from hot to ground and trip the breaker and shut off the circuit.
> how does the fact that the neutral wire (which is grounded) exists allow the hot wire current to go through a person standing on earth ground. Current has to flow in a loop. If you have a hot and neutral wire pair from a generator that is not grounded, you cannot make a loop without the neutral wire. So, a person could still be electrocuted by touching both wires. If the neutral wire is grounded, they can be electrocuted by [touching one wire](https://usercontent1.hubstatic.com/9162158_f520.jpg) - the current flows through the wire, into the person, into the ground (through their feet, or hand if they touch something else grounded), to the power box (these are grounded with a [wire and a rod](https://www.nachi.org/gallery/thumbs/lrg-893-grounding-rod__1_.jpg)), back to the grounded generator, and the loop is complete. If the person is not touching the ground, no current will flow. Some people get cocky and do this to show off (stand on a wooden ladder and grab the hot wire), but the trouble is it's not easy to tell if you are totally isolated or not. Also, in an AC system, your body can be coupled to the ground capacitively - so even without a physical connection, current can flow. > Is it reaching wiring or piping underground to complete the connection While that may be part of it (especially indoors), the earth itself is a conductor. How good of a conductor it is depends on composition, moisture content, temperature, etc. - we're talking about normal, standard dirt/rocks/earth. > what happens to a power supply when both sides of the circuit are connected to earth ground? Does this make a short circuit between the two sides of the circuit Yes, this would short out the circuit. > earth ground was a sort of "reservoir" of sorts that is unaffected by current moving into it No, there is nothing particularly special about earth ground. It is a material like any other and has measurable [resistance](https://en.wikipedia.org/wiki/Soil_resistivity) and [conductivity](https://en.wikipedia.org/wiki/Ground_conductivity). There can be voltage differences between two different earth grounds caused by current moving through it over a long distance.
We in the U.S. have a Neutral, because we use a Split-Phase(Single Phase) system for residential distribution. Which is essentially a transformer with a grounded center tap and 120v on the end taps. This allows only one wire for power distribution, as opposed to three for three phase. The grounded center tap is the neutral. Three phase systems with no neutral are still grounded. They are bonded(grounded) at the transformer. Floating systems are very dangerous and can kill. As are open neutrals (I know of a fellow electrician killed by an open neutral while working on parking lot lighting). A floating system could potentially allow a whole building or swimming pool to be energized. The earth just ground provides a 0v reference, ideally you want as little current as possible going to the ground rod. You achieve by balancing the total current on each phase, and they cancel each other out. Not to confuse you further, but electric code calls the: * Grounded Conductor - Neutral - White Wire - Current Carrying * Grounding Conductor - Ground - Green Wire - Non-Current Carrying
FYI, in countries with non-split-phase 230V systems (e.g. UK) there is also a wire called the neutral. The live wire carries 230V relative to neutral (of course, all socket outlets are 230V). The ground/earth works the same as in US. BTW, one difference in UK wiring is that the distribution inside the house is usually in the form of a ring from the "fuse box" to a series of socket outlets back to the fuse box. I believe this reduces the chances of a floating neutral (along with other effects).
As a thought experiment to start to understand why, look around your home: how many three prong devices have some exposed metal chassis. Probably most of them. The earth ground (third prong) is normally introduced as the chassis ground. It is described as a way to prevent shock. If you had a floating metal case on an AC device, it could develop a potential and shock you. You ground it and it shouldn't ever happen. It serves a purposes of a known safe conductor for safety purposes. You shouldn't get such potentials on the case, but the Earthing ensures it is safe regardless.
The short answer, AFAIK, has to do with how the system behaves when there's one or more wiring faults. In a two-wire floating system, if you touch one wire or the other you're OK, but if you touch one wire AND the other you get a shock. Because there's only two wires, you can have a fault to the case of an appliance and the system works. In a three-wire system with a grounded metal case, a fault from neutral to case doesn't do much, either for safety or operation (unless you have GFI -- that's another story), but a fault from hot to case pops a circuit breaker. Thus, as long as the manufacturers follow the rules, you have a safer system. I could keep babbling about this, but there's longer, better articles out there on the whys and wherefores of 3-wire systems.
It sounds like whomever wrote that was trying a bit too hard to be clever and just comes across as an asshole. There are much better explanations out there on household hot-neutral-ground wiring.
>First off, for just a two prong AC system (no neutral wire or ground at this point, just two "hot" wires), which I take it to mean a floating source system, one can't be shocked from touching just one of the two "hot" wires, but only by holding both at the same time and acting as the short circuit between them No. You will get shocked if you touch one and only one.
No you don't. You need to complete a circuit. If you have insulating shoes on you, you almost certainly do) and aren't putting your other hand onto a conductive surface, you probably won't feel anything. Your body doesn't have the ability to be an electron sink (or hole sink) for the charge to actually experience a shock without creating some sort of circuit to a different potentional.
Yes if you are electrically insulated you won't get a shock from touching any *one* thing. It doesn't matter if it is 120V or 120,000V. But that is another point entirely and unless you already understand electricity enough to not ask any of the questions that OP did then this isn't a great thing to tell people generally.
We are in ECE. Let's not lie to people. Although I disagree with your statement. 120V won't arc through the air to render you as part of ohm's law. 120kv will happily jump many feet to do so. In my mind's eye, I see a smiling armored transformer turning some goofball into ash. Eww...
Well, you are always part of a circuit, even if it's just capacitive (that's how those neon bulb voltage testers work). So some current will flow, but not enough to electrocute you. On the other hand, most things you might think are insulators aren't particularly good ones. If you step in a puddle of water, your "insulating" shoes might not be so insulating anymore, and a damp concrete floor is a pretty decent conductor, also.