EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: Beamin on February 20, 2018, 12:58:31 am
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So I moved into a new house built in the US in the 2000's. My lap top which has a metal case around the keyboard my iPhone and my ecig all things that have metal "feel" like they have electricity in them when you run your hand down them. I first noticed it in the iPhone thinking it was high frequency RF; it feels just like when you run your finger down a plasma globe and your finger kind of sticks I guess. But realized everything plugged in does it. The authentic iPhone power cube thing has no connection from neutral to ground correct? So this is coming from the neutral? I think I have tried my SDR out here and didn't see any noise but I'm going to try it again when I find it.
The laptop sucks because I shave my legs and arms and when the hair is really short the electric feeling hurts! As soon as I unplug my laptop I can put it on my legs again.
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If you don't get such feelings with that equipment in other locations, then there is something peculiar about your house.
Get the mains wiring checked by a competent electrician; there may be a serious problem.
As for anybody on this forum offering a diagnosis... how could they? You don't reveal your location, and electric practices vary significantly according to location.
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Live/neutral could be wired in reverse.
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Apple devices (iPads and MacBooks especially) when being used with the standard 2-pronged mains adapter are notorious for it. You can get grounded versions of the mains adapters which should eliminate this problem.
However, if you get the same kind of sensation from your metal taps (assuming you have copper/metal plumbing), you could have a bad earth or a faulty RCD (or both). Either way, it can be a serious problem and one day cause injury if left the way it is. Get an electrician to have a look.
The laptop sucks because I shave my legs and arms and when the hair is really short the electric feeling hurts! As soon as I unplug my laptop I can put it on my legs again.
Thanks for the visual. :D
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Check to see if Mike Pence owned the house before you! :-DD
Somewhat political jokes aside, I got nothing. I just wanted to make that joke, carry on.
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Apple devices (iPads and MacBooks especially) when being used with the standard 2-pronged mains adapter are notorious for it. You can get grounded versions of the mains adapters which should eliminate this problem.
However, if you get the same kind of sensation from your metal taps (assuming you have copper/metal plumbing), you could have a bad earth or a faulty RCD (or both). Either way, it can be a serious problem and one day cause injury if left the way it is. Get an electrician to have a look.
The laptop sucks because I shave my legs and arms and when the hair is really short the electric feeling hurts! As soon as I unplug my laptop I can put it on my legs again.
Thanks for the visual. :D
That's my best feature I have hot legs and feet. The other day I got three complements for them. Pink toe nail polish gets the most complements. I might have a jpeg of me in open toed high heels with my laptop on my legs if you want to see it. ;D
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Possibly bad neutral to earth bonding at the main service entrance? The neutral and ground are supposed to be bonded together at the service entrance/main disconnect. Bear in mind that when the breaker panel is more than a few feet from the service entrance the main disconnect (and therefore the neutral bond) is at the meter rather than at the breaker panel.
On one or more of the problem receptacles, measure the voltage between the hot outlet slot (the narrower one) and ground, and also between the neutral (the wider one) and ground. The hot should be 120 Vac plus or minus a few volts relative to ground, and the neutral to ground should be no more than perhaps 3-5V if the circuit is heavily loaded and in use; if not in use it should be less than half a volt or so.
From another site when I googled "US electrical code neutral to ground voltage limit":
https://diy.stackexchange.com/questions/10909/acceptable-ground-to-neutral-voltage
If you're not comfortable checking it, or if it winds up being high, obtaining the services of an electrician would probably be a good idea.
Best of luck with it.
-Pat
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That's my best feature I have hot legs and feet. The other day I got three complements for them. Pink toe nail polish gets the most complements. I might have a jpeg of me in open toed high heels with my laptop on my legs if you want to see it. ;D
Since you're sharing... go for it. It won't help diagnose your electrical issue, but it would be entertaining nonetheless.
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That's my best feature I have hot legs and feet. The other day I got three complements for them. Pink toe nail polish gets the most complements. I might have a jpeg of me in open toed high heels with my laptop on my legs if you want to see it. ;D
I take that you're a software engineer? Electrical engineers rarely paint their nails, but it is somewhat more common among software engineers. (Of course, an EE would probably already have figured it out and wouldn't be asking...)
If you have a surge protector that can check the ground, does it show any faults?
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Incidentally, I have a similar experience using my laptop on my (bare) lap (and no, I don't shave) -- the problem in this case is that the docking port is always exposed, and the tips of the power pins can just barely be touched, say by some skin that's pushed up into the receptacle by the weight of the laptop. Only seems to be noticeable in summer, which coincides with increased sweat production, and the reduced use of pants.
The current apparently can be very small. Another time, I was working on a project: bare metal chassis, battery powered (24V). With the chassis sitting on my lap, and the 24V power being fully isolated, I don't feel anything; however, if I merely touch the +24V terminal with my finger -- dry, > 300kohms -- I feel the subtle yet distinctive sensation of myriad tiny pinpricks on my thighs!
I don't know offhand if body-negative produces a different sensation (I imagine it does -- the electrochemical consequence is acid in this case, versus base in the other).
Tim
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Here's a simple, quick experiment to see if it's actually capacitive coupling from the 50/60Hz mains, or not. This assumes you don't have a multimeter. I'm basing that guess not on the toenail polish, but that you asked this question at all - which you wouldn't if you had a multimeter, since you'd have already tried measuring the voltage present, and how it varies with loading to ground.
You need only two things:
1. A definite earth ground somewhere 'nearby' where you normally use the laptop that gives you the electric feeling on contact.
'Nearby' means anywhere you have enough wire to reach, really. A metal water pipe visibly coming out of the ground is a good one.
You can't rely on water taps etc in modern houses to be 'ground', since they may be using plastic pipework. Even the taps can be plastic.
2. Some wire. Doesn't really matter what sort, just that you can bare the ends, and it's long enough.
I won't suggest using the ground pin (if any) of a mains wall socket as a ground reference, because maybe they are wired wrong, and also because of what I'm suggesting you do.
Connect one end of the wire solidly to the bare metal pipe (no paint!) Clamping it on with something like a G-clamp is best. But just wrapping a few turns of bare wire tightly round and twisting it will do. Best to clean the pipe at contact point with some steel wool or stainless scourer pad if you can.
While doing the following, don't touch the free bare wire end yourself, just in case there really is significant live voltage on the laptop.
Set up with your laptop, check that you can feel the tingle from it atm.
Hold the wire by the insulation. Touch the wire end to the laptop metal parts you get the tingle from. (You may want to tape it on.)
With it touching can you still feel a tingle from the laptop?
In the dark, can you see a very tiny spark as you touch them together? Being able to see a spark does happen, and it means the problem is quite bad.
If the tingle goes away while the ground wire is touching the laptop, then yes, it's capacitive coupling of mains through the laptop power supply. All 'ungrounded' and some grounded supplies supplies do this to some extent, but the amount varies widely depending on a few factors:
Whether the Active and Neutral wires are reversed in the house wiring. (The Neutral wire is _supposed_ to be at Ground potential.)
The amount of mains-side to DC side capacitance in the power supply. The worst cases are typically where the PS expects a mains cord with third ground wire, and has filter caps from both A & N mains wires to ground, and connects the DC 0V line to that ground, BUT THERE IS NO GROUND connection due to some wiring fault. This can be quite dangerous.
Whether the appliance, laptop etc, is double insulated. Ie is the DC supply connected to exposed metal. (Laptops mostly are connected.)
How much free space capacitance and resistance there is in your environment between your body and the Earth's surface. This can vary a lot. eg What else is your body touching? Bare feet or insulating shoes? Metal frame or insulating chair? Is the floor wooden, or concrete with steel reinforcing, etc? Ground floor or upper floors? What other wiring is nearby? and so on.
Skin can be remarkably sensitive to tiny electric currents, some areas more than others. Inner wrists for example.
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That's my best feature I have hot legs and feet. The other day I got three complements for them. Pink toe nail polish gets the most complements. I might have a jpeg of me in open toed high heels with my laptop on my legs if you want to see it. ;D
I take that you're a software engineer? Electrical engineers rarely paint their nails, but it is somewhat more common among software engineers. (Of course, an EE would probably already have figured it out and wouldn't be asking...)
If you have a surge protector that can check the ground, does it show any faults?
Thanks for all the great replies I'm not a software engineer or anything like that. You are saying the males paint their nails? I guess they are showing off their hands since that's what they use in their trade? (I think that's weird) As for "labels" of what I look like/who I am: think along the lines of Fran from fran's lab. Only small, short, and blonde hair, blue eyes, lots of pink and I'm still transitioning; I have about one year to go before possibly breast surgery (although my hour glass figure is still forming and they are still growing so I might not need it) and SRS. She has a great video out with what it's like to be a transwomen (don't ever call us "shemale" or "tranny" or any other term like that, I'm not a SJW but those are such bad terms) that people should watch to see what it's like to be in a male dominated field as female or at least as far as everyone else thinks you are female. But she is much more of a tomboy where I am more (ALOT more) on the girly side and date strong/tall/masculine men. I usually don't tell people that on forums because of "leg humping"/ constant PM's for nude pictures and they usually include a picture of their little shrived up dick or old man balls (yes it's gross); Here's a tip: Women don't want random penis pictures in their mailbox. I'm not sure how you get a date but I'm 100% sure that's how you don't. Also it's attention that distracts from the threads purpose. Maybe I'll post a teaser picture, depending on the reception of this thread, as a thank you for figuring this out. I just got "zapped" again! If this is too much info I'm sorry but it clears up a lot of confusion to come out to people and helps me be more comfortable with who I am. Nothing about this is easy (think if you woke up one day without your male genitalia and were forced by the norms of society and discrimination to: wear dresses/make up, had breasts/long hair/no big muscles, and had to date/be romantically involved with men. That's exactly how I feel but only 100% opposite, so It's really hard dealing with that but in this country there is a cure provided you have the right body type; I'm very lucky I was born with mostly feminine features and small stature/hands feet etc) but neither is life or electronics which is why I like it. ;) Also if you just have questions maybe you know a trans person but are confused with pronouns or how to interact tactfully or just are curious feel free to ask me. Or if you have ever had these feelings yourself and just need someone to talk to in confidence PM me (no penis pictures PLEASE :P ) and I can help you decide if it's just a feeling that will pass or if it's real and transitioning will finally free you. If it wasn't for asking someone online on a tech forum I might still be trapped in a male body living a miserable life, so I will help/share anyway I can. ;D I think that a lot of trans people (but don't know they are trans yet) like tech forums but are afraid to come out.
-Lexi
Anyways...
At another place when I measured from neutral to ground I got a reading of 60 VAC I'm guessing that just coupling and has no real current behind it? So that is bad wiring or normal for long parallel wires to do that?
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If you're seeing 60V between the neutral and ground, then there's definitely a bonding problem. What is the reading between the hot and the ground?
-Pat
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I had the same (electrical) problem, but only at night. After a long search over a few weeks it turned out that the public street lights had a bad wiring and leaked voltage to ground.
After I reported it, the electrocity company quickly fixed it.
Regards,
Vitor
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I had the same (electrical) problem, but only at night. After a long search over a few weeks it turned out that the public street lights had a bad wiring and leaked voltage to ground.
After I reported it, the electrocity company quickly fixed it.
Regards,
Vitor
That's scary. I still haven't found my multimeter so results as soon as I find it! I suspect its some appliance or something in the house.
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At another place when I measured from neutral to ground I got a reading of 60 VAC I'm guessing that just coupling and has no real current behind it? So that is bad wiring or normal for long parallel wires to do that?
I seem to recall that some (all?) 120V AC wiring systems use street transformers where the 120V customer-side winding is center tapped, with the center being grounded, and the two live wires being 60V AC anti-phase, ie 120V AC.
The theory being that's a relatively (ha!) safe voltage to ground. But that was just something I read somewhere.
Here in Oz we use 240AC, grounded-Neutral domestic wiring, with transformers only at area level (a few housing blocks, or per-factory) for the 3-phase 11KV 3-wire delta distribution to 3-phase 415V/240V 4-wire grounded-center star conversion.
The way to tell if AC voltage present on the outside of an appliance is due to a fault, or just capacitive coupling, is to measure how the induced voltage changes with resistive load to a true ground. Something like a 10W 2K2 ohm resistor will drop it to very little. (Only needs to be a big 10W one, in case you're dealing with a direct connection to mains. In which case you're risking your life anyway. Normally a tiny 1/4 W resistor would be fine.) And then you can work out the current and hence the capacitance of the coupling.
The suggestion to try a direct wired short to ground, is assuming it's definitely only a small capacitive coupling. Because if it was a direct conductance fault, you wouldn't be alive now to ask the question.
Re multimeters - ha. What's even more stereotypical of non-technical nature than not having a multimeter?
A: Having one, but not knowing where it is. :)
Btw, when you do find it, what are you going to measure the laptop case voltage relative to?
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Terrahertz -
In the US, residential power comes from a 240V center tapped distribution transformer - it is 240V line to line, and 120V line to neutral. The neutral is connected to the center tap of the distributioin transformer, and is connected to earth ground at the service entrance to the dwelling. The neutral should not be more than a few volts at worst (that under heavy load due to IR drop in the run to the breaker box) above ground potential, and should typically be less than a half a volt or so (as it is, if properly wired in a typical branch circuit, a piece of #12 or #14 AWG wire that is bonded to ground where the power enters the house.
60V from neutral to ground indicates that something is amiss.
-Pat
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One quirk of this is, similarly as 60V would put something amiss, 180V would be the other side of that! If the neutral becomes floating, this can happen; there are UL standards regarding equipment tolerating this condition, especially for MOVs, that will slowly cook off, because of the low current available in such a condition -- the stronger phase's load is acting as a current limiting resistor for the other side's voltage protection devices.
Related hijinx: using 120V outlets from different parts of the house, to get a 240V 15A circuit. Very risky because the breakers are not connected (a normal 240V circuit is simply two breakers ganged together), so in a fault, only one phase will open, and the other remains live.
Very rare situations though, nothing that's supposed to happen in a normal wiring situation. Sort of like automotive load dump, extremely rare, but possible and still must fail in a safe manner.
Tim
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If you know how to safely work with high voltage (if you don't, find someone who does - try a local hackerspace), measure voltage between the AC ground and a known good ground like a cable TV connector while temporarily connecting a 100W or so resistive load between hot and AC ground. (That won't work on a GFCI circuit for obvious reasons.) The voltage reading will tell you roughly the ground impedance.
On the topic of why very few electrical engineers paint their nails, nicely finished nails won't stay nice for very long after handling bare PCBs! The fiberglass PCBs are made of is quite abrasive. (Very nice clothes don't get along with bare PCBs either - hence why engineers typically only dress really nice when they have an interview or other event to go to.) Software engineers generally don't deal with bare PCBs and thus don't encounter that problem.
I also have to say that the stereotype that women should not be strong is something that should be challenged and eliminated. Just watch the Olympics to see strong women who are proud of it. Or for more everyday examples, Rinoa Super-Genius is able to lift one end of a Nissan Leaf battery and my friend Brittany Benzaia is also pretty strong. Former Qualcomm model Diana Navarro enjoys weightlifting (even at a very "casual" level) for fitness.
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So measured the outlet:
Neutral to ground on 200V AC range of cheap meter. (need to get a fluke I know) reads a steady 0.
hot neutral = 120.5 to 121.5
hot ground same with the fluxuations being the same. Also there was a dryer running down stairs so I don't know if that would mess things up.
I didn't see the strange voltage that I got at another place I lived between neutral and ground. Seemed like it was spot on.
Could there be other voltages or high frequency things that my meter wasn't reading? I also have a tech 3000 series scope from the 80's but I'm not sure how I could safely measure the mains without hurting it or what settings to use (I still sometimes pick up noise thinking its my signal: turning off the device under test only to see the trace not move.). I have some large resistors and caps so I could build a probe if I have plans to follow.
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Ok, so that rules out a failure in your neutral - ground bond. also that your likely in the US based on the voltage. (you never actually said your region)
Next up would you be able to measure between say a metal tap and the ground of an outlet, this is to rule out that its not a break at a ground stake (if they are used there)
And finally, Is your laptop charger grounded or ungrounded? If grounded, with a break in a ground rod, I could forsee the AC coupling caps charging up the laptop chassis to 60VAC, (very low current, but enough to be felt as a zap)
Its very unlikely to be high frequency, So your multimeter should be just fine for the task.
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Ok, so that rules out a failure in your neutral - ground bond. also that your likely in the US based on the voltage. (you never actually said your region)
Next up would you be able to measure between say a metal tap and the ground of an outlet, this is to rule out that its not a break at a ground stake (if they are used there)
And finally, Is your laptop charger grounded or ungrounded? If grounded, with a break in a ground rod, I could forsee the AC coupling caps charging up the laptop chassis to 60VAC, (very low current, but enough to be felt as a zap)
Its very unlikely to be high frequency, So your multimeter should be just fine for the task.
Yes US. So when you say a tap you mean water tap? This house is only ten years old so I believe they use WPVC (how you can make PVC safe when the dangerous part is the C in PVC is beyond me.) in fact I know they do.
The lap top has a three prong outlet dell power supply. Even in a SMPS doesn't the ground and neutral get connected through the circuit? I think I saw a eevblog video on this but that might have been a linear supply or variac with a common ground.
Another question: I was trying to make a HPS grow lamp safe at another house. The power cord from the transformer to the bulb and metal fixture I chose not to run the ground to the fixture up the cord to the light bulb from the transformer. My thinking was if you were standing in water and touched something grounded; maybe the transformer was conducting into the water since it sits on the floor, there wouldn't be a circuit running through your body as the metal would be floating. I then realized this didn't matter because the transformer was wired so that both coils were tied to a common neutral; no isolation. I don't know why they do that. It makes it hard to get big isolation transformers as the common connection is inside the winding and can't be separated.
I had one of these as a kid and when I earthed the fixture using a three conductor extension cord I would find the cord arcing through the insulation (standard orange heavy gauge extension cord) when the cap charged up to strike the arc it would arc across the wire to the fixture instead of going through the lamp. Yes the wire wasn't rated for this voltage but I was like 16 and trying to be sneeky and just used lots of silicone and made sure I was around when the light was turned on.
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Could bigclive have your answer?
https://www.youtube.com/watch?v=YP8okiLOdKk&t=903s (https://www.youtube.com/watch?v=YP8okiLOdKk&t=903s)
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Yes, water tap, even if you have only plastic pipes, the water between your tap and the pipes in the ground will only be 100's to 1000's of ohms, so compared to the 1M ohm resistance of the meter wont be a problem,
That or a concrete floor. (comparing ground at the outlet to effectively the house / plot of land around you)
Being a grounded plug you can also check the voltage between the laptop frame and outlet ground, by rights he should be 0V AC, if not the charger may be leaking current across the transformer (somewhat concerning)
Other questions:
PVC can be considered safe in the same way lead piping can be considered safe. if the water source does not contain components that react with the piping, and the piping does not decompose in to the water stream at a rate higher than found problematic in studies, then its safe for use. If you do hold fear, you run the tap for a bit before you drink to reduce the concentration,
In the nitty gritty it comes down to what plasticizes / additives where used in its production, being a thermosoftening plastic, they are generally less likely to seep out of the plastic unless heated.
For the grow lamp fitting, its more if someone accidentally breaks the globe, the goal is to be more likely to contact the ground than the live contact(s), the same as say a toaster, for a kid to pry something out with a knife, he will be in contact with the case, if its a RCD / GCFI circuit then him touching the case should trip it if he touches something bad, and for normal circuits the hope is that what you bridge the contacts with will trip the circuit, in the case if its your finger, then you may still get zapped,
For electric zaps, anything that stays away from your chest area is within certain limits, painful but survivable. live mains across your fingers, but with the rest of you insulated will hurt like buggery, but not near the heart so unlikely to cause problems, with you feet in the water, you main hope would be the current chasing the lamp fitting ground rather than one at your feet. as even if the puddle is not directly connected the ground it still makes a poor path through capacitive coupling.
The neutral is treated separately to the ground, It has a few functions, To make it so the dirt around your house is tied to the same voltage (without it, in lightning storms you can see hundreds to thousands of volts difference as the charged cloud passes overhead), To shunt any fault currents, e.g. knife in a toaster in the hope of popping the fuse / tripping the breaker. To trip a breaker that detects an imbalance of current, and more recently, to shunt higher frequency noise via some capacitors back to the reference point of the dwelling,
These capacitors however will leak some current as there impedance at 50/60Hz is not infinite. e.g. 10nF, so leaking in the order of 400uA,
And for the final one, a normal extension lead is at best able to withstand 1000V, with most high pressure sodium lamps running on the order of 2500V, I can understand it arcing.
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how you can make PVC safe when the dangerous part is the C in PVC is beyond me.
Oy vey, that’s not how chemistry works. You do know that table salt (the stuff you need to live) is sodium chloride, right?
The thing to remember about reactive elements is that the more reactive they are, the less reactive compounds made from them are, because the reactivity is from the strong bonds it wants to form, and those strong bonds don’t want to release once made.
Aluminum metal objects resist ordinary corrosion because aluminum is so reactive, it instantly oxidizes, and as it happens, aluminum oxide is very non-reactive. Fluorine is spectacularly reactive, which is why fluorinated compounds are so extraordinarily non-reactive (Teflon, Fluorinert, etc etc etc).
Back to PVC. The chlorine in PVC is released only when PVC is broken down, most commonly through incineration. Flexible PVC (“vinyl”) objects have an entirely unrelated health issue, the phthalate plasticizers, but that’s not relevant to rigid PVC pipe since they don’t use plasticizers.
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Live/neutral could be wired in reverse.
Since he said it was a (relatively) new house in the US, all outlets should be 3-prong. You can get an "outlet tester" at the hardware store for about $10. It will detect incorrect hot-neutral wiring. Just plug into each outlet and observe the lights. Everybody ought to have one of these, given the number of expensive electronic stuff we all have, now.
open neutral is serious stuff, and can burn out all the appliances in your house. This is where the neutral wire from the utility service becomes disconnected. Appliances that are supposed to get 120 V get anywhere from zero to 240 V, depending on other loads in the house.
Jon
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Is your new house outside of city limits? Maybe in a "DRB" development? (DRB = acronym for one of, if not the WORST-and largest- developers in the US)
If you're outside of city limits, more than likely the developer wasn't required to adhere to CODE and never had any inspections done during the building process. ALL of DRB's developments in my area are strictly outside of city limits for this sole reason. They are then legally allowed to cut corners in every aspect of building. The most horrifying things I've seen in these houses were with the electrical systems. Literally NOTHING was done according to CODE, and most of the time they wouldn't even use OX-Guard on the aluminum electrical connections. Other examples include running lines diagonally through floor joists, failing to use nail plates (so no one accidentally screws/nails through a wire or water line), using dry-location boxes on the exterior, failing to use GFCI in 'wet rooms', etc.....
I used to install HVAC systems in their houses, so I had the opportunity to see just how awful their homes really are. I've also finished a few of their basements after the homes were purchased, and absolutely NOTHING is level, plumb, or square. Those issues aren't safety hazards, but goes to show just how little they care about their products and their customers. It baffles me that they've not had any class-action lawsuits filed against them.. yet.
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Definitely sounds like some bad grounding/bonding issue. Here's a few tests you can do with a volt meter:
Probe between the neutral and ground of an outlet. Neutral is the left side, and is a bit longer. You should get 0.
Probe between the hot and ground of an outlet . Hot is the other blade. You should get 120v.
Now find an outlet that is relatively close to a water line or a known earth ground. Even a gas line will do. Probe between the outlet ground and that pipe. You should get 0.
It may also be an open neutral as suggested, do you notice some lights are brighter than others or some things act weird depending on if you turn on/off other things? With a floating neutral what happens is half your house will be in series with the other half. (well not exactly half it really depends on how stuff is wired). This can be a dangerous situation as it can cause near 240v to go to certain items.
This reminds me actually, I need to redo my main ground. Got my water valve changed and the plumber used pex so it broke the ground connection. Need to run a longer cable and reattach it where it's still copper.
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Ok, so that rules out a failure in your neutral - ground bond. also that your likely in the US based on the voltage. (you never actually said your region)
Next up would you be able to measure between say a metal tap and the ground of an outlet, this is to rule out that its not a break at a ground stake (if they are used there)
And finally, Is your laptop charger grounded or ungrounded? If grounded, with a break in a ground rod, I could forsee the AC coupling caps charging up the laptop chassis to 60VAC, (very low current, but enough to be felt as a zap)
Its very unlikely to be high frequency, So your multimeter should be just fine for the task.
This is something which can occur if the "chassis" of your device is not connected to ground, but there is a symmetrical low pass filter network connected at the Mains input.
These usually have inductors in series on both sides of the Mains & capacitors connected between both sides & chassis.
In this case, they form a capacitive voltage divider, & the chassis takes up a voltage of half the Active line voltage,w.r.t Neutral, & hence, Earth.
This happens fairly frequently when equipment which was designed to operate on the US "split phase" system ( 120v between either " hot" & Neutral, 240v between "hots") is used on the Australian style 230v (nominal) Active to Neutral system.
In the USA, the chassis is at "virtual" Earth, so there is no ( or very little) potential between chassis & Earth.
In Oz, the chassis will be at 115v( nominal,often a bit more) w.r.t Earth.
The capacitor impedance at Mains frequencies is high enough that you can't get a dangerous shock, but you can definitely feel it.
It would seem unusual for a 120v device to have such a symmetrical filter, but the "60v to Earth" result points that way, rather than just a single cap from "hot" to chassis.
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how you can make PVC safe when the dangerous part is the C in PVC is beyond me.
Oy vey, that’s not how chemistry works. You do know that table salt (the stuff you need to live) is sodium chloride, right?
The thing to remember about reactive elements is that the more reactive they are, the less reactive compounds made from them are, because the reactivity is from the strong bonds it wants to form, and those strong bonds don’t want to release once made.
Aluminum metal objects resist ordinary corrosion because aluminum is so reactive, it instantly oxidizes, and as it happens, aluminum oxide is very non-reactive. Fluorine is spectacularly reactive, which is why fluorinated compounds are so extraordinarily non-reactive (Teflon, Fluorinert, etc etc etc).
Back to PVC. The chlorine in PVC is released only when PVC is broken down, most commonly through incineration. Flexible PVC (“vinyl”) objects have an entirely unrelated health issue, the phthalate plasticizers, but that’s not relevant to rigid PVC pipe since they don’t use plasticizers.
Yes biochem is incredibly complex with interaction of compounds on proteins. Hemoglobin has one Fe atom and an atomic weight of around 50,000 so saying Fe reacts with O2 is way over simplified. Dioxin is actually not that dangerous but its analogs like used in industry are incredibly dangerous. The difference in dangerous terrible meth and your kids helpful friendly Adderall molecule is just a CH3 instead of H. When you add DNA into the mix it becomes very hard. The plastic industry has a terrible track record of changing laws to make things "safe". Leaded gas wasn't completely phased out until the 1990's in NY and it was poisoning EVERY American.
So that feeling of electricity went away? As I don't control this house I have no idea what changed but it must have been a bad SMPS power supply? Is that the consensus of the thread? One person moved out but I can't say for sure when I felt this change as my lap top was down for a while. I'm running my arms around it now which are completely smooth which would normally shock me.
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Did it rain recently?
If your ground is intact other noisy SMPS's in the house should have had there noise shunted, however if your grounding isnt quite perfect it may have made the problem more apparent by shunting more current.
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And for the final one, a normal extension lead is at best able to withstand 1000V, with most high pressure sodium lamps running on the order of 2500V, I can understand it arcing.
Most high pressure sodium lamps have an operating voltage of around 100V, with the current limited by the ballast. In 120V countries there are 55V versions of the 100W and smaller HPS lamps for use on 120V circuits with simple choke ballasts. The large 1kW HPS lamps are a bit unique, operating at 250V due to the long arc tube. Perhaps you are thinking of the HV ignition pulse required to get the lamps started? Due to the constraints resulting from the extremely reactive nature of molten sodium metal, HPS lamps lack the starting probes used in mercury and earlier metal halide lamps so they have always required an electronic igniter to get them going.
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So I moved into a new house built in the US in the 2000's. My lap top which has a metal case around the keyboard my iPhone and my ecig all things that have metal "feel" like they have electricity in them when you run your hand down them.
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Another possibility - this may be a shot in the dark... Did you moved from a more humid place to the USA? It may be that you are still very sensitive to static electricity. Year 2000 (when you build your house) is a long time ago, but if you did not grow up with it, it is a possibility.
I had a visitor from Hong Kong and he was shocked to be shocked. That was one thing he had never experienced in his life before. He actually called the hotel front desk multiple times to "fix the door knob" - this predates the electronic door knobs. That door knob was just a plan old key-lock door knob on a wood door. He was not alone. With some of my "growing up humid" friends, a few just retained their sensitivity decades later.
May be you are still very sensitive to the static? Does it happen the second time (post static discharge) you put the laptop on your lap?
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Tis was a 250W HPS and the one that arced was a 1000W HPS and when it would start the cord would keep arcing to the housing with the light flashing alternately between the sparks. Once the light ran warmed up for a minute the arcing stopped. It had a huge metal cap (2"X6"X6") next to the huge transformer.
So I moved into a new house built in the US in the 2000's. My lap top which has a metal case around the keyboard my iPhone and my ecig all things that have metal "feel" like they have electricity in them when you run your hand down them.
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Another possibility - this may be a shot in the dark... Did you moved from a more humid place to the USA? It may be that you are still very sensitive to static electricity. Year 2000 (when you build your house) is a long time ago, but if you did not grow up with it, it is a possibility.
I had a visitor from Hong Kong and he was shocked to be shocked. That was one thing he had never experienced in his life before. He actually called the hotel front desk multiple times to "fix the door knob" - this predates the electronic door knobs. That door knob was just a plan old key-lock door knob on a wood door. He was not alone. With some of my "growing up humid" friends, a few just retained their sensitivity decades later.
May be you are still very sensitive to the static? Does it happen the second time (post static discharge) you put the laptop on your lap?
No its not static. Feels like a plasma lamp glass with dry hands but much stronger. Its been around freezing here and hasn't really rained much. Electricity feeling is constant. Like high pitched buzzing.
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"it feels just like when you run your finger down a plasma globe and your finger kind of sticks I guess. But realized everything plugged in does it."
Going to buy stuff today reminded me of your posting! 8)
It was not mentioned in the thread but are you close to powerlines at all?
The parking lot is located just under a high voltage transmission line. Over the years I noticed that if I pass my hand gently across the car I get that 60Hz tingling sticky/prickly sensation. Particularly using the back hand or wrist. If someone else is touch the car it goes away (they ground it).
I then brought a live line detector (shown in pic). It is meant to detect live circuits but, in essence, is an E field detector. Pointing it upward under to power-line sets it off strong.
So I would suggest to get a that gismo with LEDs to check the electrical system in your house for the hot-neutral-ground issues and check all the receptacles in your house first with it.
Then get the E field detector and use it on the suspect equipment. Both are about $10-15.
Finally remember that many older, cheaper, "double-insulated", whatever devices that only use a two prong connector are suspect.
Some older HiFi, radios, TV with two prongs (some had a wider spade to polarize assuming the socket was wired properly) have a small cap on the "neutral" side of the line and the metal chassis will have a small leakage.
Rotating the two-pronged connector will solve the problem. In older HiFi setups getting them all right and grounding the lot to a copper pipe used to work to eliminate hum and ground loops.
The point is testing each was easy by passing your hand gently on the metal front panel (or the tip of your nose) just as you mentioned.
Some people were very sensitive to the feeling and others completely oblivious.
Finally invest in a good high impedance DMM to really trace the issue.
Hope that helps.
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"it feels just like when you run your finger down a plasma globe and your finger kind of sticks I guess. But realized everything plugged in does it."
Going to buy stuff today reminded me of your posting! 8)
It was not mentioned in the thread but are you close to powerlines at all?
The parking lot is located just under a high voltage transmission line. Over the years I noticed that if I pass my hand gently across the car I get that 60Hz tingling sticky/prickly sensation. Particularly using the back hand or wrist. If someone else is touch the car it goes away (they ground it).
I then brought a live line detector (shown in pic). It is meant to detect live circuits but, in essence, is an E field detector. Pointing it upward under to power-line sets it off strong.
So I would suggest to get a that gismo with LEDs to check the electrical system in your house for the hot-neutral-ground issues and check all the receptacles in your house first with it.
Then get the E field detector and use it on the suspect equipment. Both are about $10-15.
Finally remember that many older, cheaper, "double-insulated", whatever devices that only use a two prong connector are suspect.
Some older HiFi, radios, TV with two prongs (some had a wider spade to polarize assuming the socket was wired properly) have a small cap on the "neutral" side of the line and the metal chassis will have a small leakage.
Rotating the two-pronged connector will solve the problem. In older HiFi setups getting them all right and grounding the lot to a copper pipe used to work to eliminate hum and ground loops.
The point is testing each was easy by passing your hand gently on the metal front panel (or the tip of your nose) just as you mentioned.
Some people were very sensitive to the feeling and others completely oblivious.
Finally invest in a good high impedance DMM to really trace the issue.
Hope that helps.
I know what you mean about power lines. I used to hit golf balls under some big transmission lines and you would get a painful shock when you would touch the metal ball buckets.
So this house is not around power lines and has under ground wiring on the street and most areas of this town. The owner is a complete idiot and I just rent part of the house so other then my own personal safety or fire I don't have much control. I seriously think the owner has some sort of brain problem because nobody is this stupid so it's pointless to ask him questions.
I have watched a bunch of videos on this and gave me more questions. Only variable I can rule out is when he moved his stuff to another bedroom it seemed to go away.
If the power brick to the lap top has a ground on the plug how far does that go? Is it tied to the neutral side of the transformer in the supply? Or is the ground just to dump RF noise? I can't see the path from the metal case to the body the body as being least esistance unless it is high frequency or high voltage/high frequency, low current.
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OK so the electricity is back!!!!!
I have plugged in a 250W watt power conditioner box that is just a huge torroid.
Multimeter values soon to come and it has started raining so I don't know if that plays a factor.
And because someone asked what my legs looked like here is a teaser pic. I spend a lot of time making them look nice and can't have them getting zapped! You can also see my electronics spread around the back ground.
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The zero voltage between the neutral & earth is problematic. Unless everything is turned off there should be some voltage there. Somewhere between .5 & 2 volts. The heaver the loading the more voltage difference. Zero volts may indicate the neutral & ground have been re-bonded after the service entrance.
Take a load like a heater or hair dryer, plug it into the outlet, turn it on & re-measure the neutral to earth connection (between the long slot & the U-shaped slot) in the same outlet or one you are sure is on the same branch circuit. You may need to lower the meter range.
I normally wear some 9mil nitrile gloves when measuring. Any non-conductive gloves are better than none, including cotton. A cheep meter's leads may allow your fingers to slip down the probe.
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If you foot the power bill or maybe even if you don't you could complain to your utility and they will usually send a truck by just to have a look and make sure there is nothing dangerous. Usually this is a free service since its usually part of their normal random inspection plan for people stealing power etc or just flat out doing really stupid shit like by passing main breakers etc. That and they really do want people to be safe and not end up dead.
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The zero voltage between the neutral & earth is problematic. Unless everything is turned off there should be some voltage there. Somewhere between .5 & 2 volts. The heaver the loading the more voltage difference. Zero volts may indicate the neutral & ground have been re-bonded after the service entrance.
Take a load like a heater or hair dryer, plug it into the outlet, turn it on & re-measure the neutral to earth connection (between the long slot & the U-shaped slot) in the same outlet or one you are sure is on the same branch circuit. You may need to lower the meter range.
I normally wear some 9mil nitrile gloves when measuring. Any non-conductive gloves are better than none, including cotton. A cheep meter's leads may allow your fingers to slip down the probe.
Where does this voltage come from? capacitive coupling?
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On a 120VAC circuit the ungrounded conductor (HOT) & the grounded conductor (usually called a NEUTRAL) form the circuit that delivers energy to the load. Since copper/aluminum conductors are not perfect they have some resistance. A small voltage drops across that resistance.
Lets say you are measuring a properly wired outlet with an attached load:
The HOT to Neutral measurement is the voltage applied to the load.
The HOT to Ground (earth) measurement is the available (or original) voltage at the panel. This is because the Equipment Grounding Conductor (green wire) does not carry any current under normal conditions. No current no volt drop.
The Neutral to Ground (earth) measurement is the volt drop caused by the load.
The difference between the HOT to Neutral measurement & the Hot to Ground measurement it is equal to the Neutral to Ground measurement. Funny how things add up sometimes.