Two-pin devices leak electricity?

konnichiwa · Oct 9th, 2009, 16:37

Some of my US electronic devices are two-pin devices (e.g. Dell laptop charger, iPod charger), but are rated 110-240V so I can plug them in to Indian sockets with just a flat-pin to round-pin plug convertor.

However, I noticed that these devices leak electricity when connected at my home (in central New Delhi) and office (Noida) - a USB cable attached to my laptop has given me a mild shock. I asked my local electrician to check out the "earthing" of my home electric panel and he says that he's done what he can - the problem will not occur with three pin devices, but persists with two-pin devices. It's interesting that the same problem exists at my office, but all devices at work are three-pin in any case.

I guess I can try and buy and fit three-pin plugs to my two-pin devices & figure out how to ground the two-pin, but I am curious to find out if anybody else has faced this problem in India. Could be a potential hazard, especially if you have little children around.

Thanks!

traveller.1 · Oct 9th, 2009, 16:46

My lap top too was giving me shocks. I bought a 3 pin adapter and I no longer have elctrifying moments

machadinha · Oct 9th, 2009, 18:16

Quote:

Originally Posted by konnichiwa

I asked my local electrician to check out the "earthing" of my home electric panel and he says that he's done what he can - the problem will not occur with three pin devices, but persists with two-pin devices. It's interesting that the same problem exists at my office, but all devices at work are three-pin in any case.

(As far as I know) two-pinned plugs aren't grounded by nature. (The third pin is there to provide the grounding; via the grounding cable,* of course. You have your plus and your minus, and then the third is for earth.)

Three-pinned plugs and sockets aren't if the entire electricity network in a given room or building, or parts of it, or those plugs and sockets themselves then, aren't (adequately) grounded (e.g., lacking or faulty grounding cables, or not properly grounded themselves. If that grounding cable leads to nowhere, i.e., isn't grounded at all, it won't do you any good.)

* Edit: I'm not so in on the proper English names for all that stuf; as per Nick's below, maybe read "earth wiring" here for "grounding cable." It's just a third wire in a standard electric cable; if indeed it contains one, there exist those that don't.

Nick-H · Oct 9th, 2009, 18:39

Hmmm... two-pin devices, by definition, have no earth, so the earth wiring of the socket should be irrelevant. Non-earthed devices are often double-insulated so that it is not possible for live components to be touched.

Your chargers/power supplies are supplying a lower voltage to your devices anyway. I'm no expert, but I would have thought that if a high-enough current is passing through your laptop motherboard to give you a shock, the laptop will fry long before you do.

Mind you, one can feel quite low voltages. I notice the shock from telephone wires here --- but only when I am bare-foot. I suspect that the higher humidity, plus sweatiness, plus bare feet, makes me notice current that I would never have noticed in UK. Just theory --- if there are any experts, I'd be interested to know if there's anything in it.

machadinha · Oct 9th, 2009, 18:47

Me no expert either. But I think climatic conditions could matter yes (conversely, very dry conditions could be of influence I think, as in static electricity); and while it may sound a little esoteric, some people seem more prone than others to attract electric shocks, even at low voltages. Presumably something to do with personal chemistry or so.

Messed-up electrical wiring to begin with also springs to mind as a cause, of course

thejag · Oct 9th, 2009, 19:13

The chargers convert AC into DC and feed it into your devices... what ever youre feeling is the device itself either short circuiting or malfunctioning or not being used as per specifications as the manufacturer puts it. Did you notice this sensation only with the USB cables or were there any other symptoms....with any other device or cable? the USB cables carry a 5 volt feed... but thats only on one of the inside pins which your fingers will never be able to touch. the outer metal casing connects with the shielding in the cable (if any) and which further connects to the Casing of the Laptop/desktop and will carry a current only if a short circuit on the PC side is leaking current into the casing.... or the cable is mutilated somewhere on the inside....

What nick says is correct. you will feel the current flow if you touch any exposed terminal or device bare feet.... thats how the current that enters your body flows out of it.. or if you are holding something else with the other hand that eventually touches the ground...

And nick the current doesnt have to be very high to give you a shock.... all it needs to enter your body and give you a shock is a way for it to flow further away.... and just to dispel a myth its the current that kills not voltages.... hundreds of thousands of volts flowing through a human body will not harm it if the current is small enough... and if anyone wants to see this search for van de geaf generators (its been a long time so pardon the spelling mistakes if any) and you will see these generators pumping out thousands of volts (science project level) or even millions of volts and the only side effect would be your hair standing on its ends....

Oh and after all this i also recall some thing at the office... we had a directive from the technology team to every one to stop plugging their chargers into sockets meant for PCs... apparently some chargers were short circuited and the resulting feedback ( i dont remember the actual tech terms) was causing the UPS to malfunction.... we were told we could continue to plug the chargers into sockets fed directly from the mains... but not the UPS... so i guess chargers can continue to work even though they can mess up things but i think i dont recall the exact problem cause now that i read what i wrote it doesnt seem to make sense to me.... bah it was so far back....

dillichaat · Oct 9th, 2009, 20:01

OK guys, I know nothing about electricity but I can confirm that whenever I plug my macbook (aluminium body) directly in the mains, I get shocked. There actually is current running through the bloody thing! If I put one of my power strips between, no problem. Don't understand how that can be though. If the wiring in the building is not grounded and allows a current to flow through the laptop body, then how can the problem go away when I use a power strip??

Anyway, it has no adverse effects that I can notice on the laptop. Still think it's poor design, though. You shouldn't let user safety depend on external factors.

traveller.1 · Oct 9th, 2009, 20:04

Mine too is a macbook pro. I think that our devices are intended as 3 pin devices. The adapters that you get overseas are 2 pin and in place of the 3rd pin in the US we have a metal earthing point. Our sockets have a screw where the earthing point gets earthed. The Indian plugs do not have a earthing point

thejag · Oct 9th, 2009, 20:50

urrgh.... why the hell did i not think of this before.... its not the metal case releasing current into your hands or your body... its your body discharging static electricity into the Metal cases...

If the shock is accompanied by an involuntary muscle spasm then it is electrical discharge from the device into your body... thats dangerous and indicated a malfunctioning device that needs to be repaired... (this is from a quick google search) a buzz when you touch the device in question is just your body discharging static into the device... the most common way for the static to build up?????? shoes scuffing on carpets or special flooring.... and nick and mach are right about the climate, certain conditions are more conducive to this static buildup than others....

back in late 2004 the pair of shoes which i wore then with the carpets at my last work place literally made me zap everyone i came in contact with... took me a couple of weeks to figure out that the shoes were the culprit.... i feel like such a fool for not realizing this sooner.... the reverse flow! not the shoes!

Indian plugs have an earthing point... and thats precisely why this is happening.... or atleast the device is acting as an earthing point and swallowing up the static.... in which case it can literally blow up.... the current can be high enough to take out certain capacitors....

PS: Dillichaat local power strips do not include an earth wire in the internal wiring... i have enough dead SMPS units to attest to it, finally wired my own extension boxes with parts from the local store, three triple socket boxes power the PC/monitor, the chargers, the STB, the ext TV tuner, the speakers and a hell of a lot more that comes and goes and not a single problem.... maybe thats why no discharge channel and no shock when you use a power strip in the middle.... no earth no discharge path???

dillichaat · Oct 9th, 2009, 21:19

Quote:

PS: Dillichaat local power strips do not include an earth wire in the internal wiring... i have enough dead SMPS units to attest to it, finally wired my own extension boxes with parts from the local store, three triple socket boxes power the PC/monitor, the chargers, the STB, the ext TV tuner, the speakers and a hell of a lot more that comes and goes and not a single problem.... maybe thats why no discharge channel and no shock when you use a power strip in the middle.... no earth no discharge path???

Nope, I used a strip that I brought from Europe, with grounding.

Don't know if it's static electricity either because that's usually a one-off discharge. With the laptop, it just keeepsss coming

If we've got any members who kick on this type of electrocution thing: get a macbook pro!

konnichiwa · Oct 9th, 2009, 23:14

Just to clarify - it's not static. The electrician and I both tested the current flow in the USB cable with a tester (with shoes on). And the tester also tested positive for metal screws & other metal parts on the body of the laptop. And there's current on the outside of the adaptor plug that goes into the laptop.

Checked the laptop with a 3-pin adaptor - no current flow. So it's got to do with 2-pin. There's no difference in results if I put in a power srip in the middle or directly plug in the adaptor.

Still not sure what the solution is, other than changing the adaptor to a 3-pin (which I can do with the Dell laptop adaptor as the Indian versions are 3-pin), but what about the iPod adaptor?

Nick-H · Oct 10th, 2009, 00:17

Static will discharge as a shock, and that's it, gone. A buzz is not static, it is current leakage, and you can prove this by putting a meter on it.

Yes, Indian 3-pin sockets have an earth pin. It may be wired. The earth wire may go somewhere useful, or it may not. My house was professionally re-wired, including lots of green-covered wires connected to earth pins. Only thing was, it didn't go to earth anywhere. I only discovered this by getting an unpleasant shock from the microwave due to a short circuit in an AC machine! An EB engineer told me that this is very common, that they just don't bother to put an earthing point. We have one now.

Some of those European two-pin plugs do have an earth. I vaguely remember... a metal contact between the two pins, or on the side of the plug? If this is the case it could explain why your European power strip is taking that current leakage to ground.

machadinha · Oct 10th, 2009, 00:24

Quote:

Originally Posted by Nick-H

Some of those European two-pin plugs do have an earth. I vaguely remember... a metal contact between the two pins, or on the side of the plug?

That is correct, and there are such plugs here, quite common in fact, more so than the three-pinned ones (they'll have a socket fitted just for them though and to accommodate that metal strip, and so again a grounded one, if they have indeed been grounded -- there's nothing to force you to properly connect the socket); in any case the gist of my story was there's not much point in plugging a device whether grounded or not into a non-grounded circuit, safety-wise it won't matter a thing.*

(All very obvious, I know, but then it gets overlooked a lot.)

* That's not to say everything around you will automatically explode, but a good and common sensible thing to do would be to not hook up e.g. refrigerators in there, i.e., any heavy devices.

Again, with the OP's description and some others I've seen and some things I've experienced in India and some other places though, I'd be more worried about the state of my electrical circuit to begin with. Like you say, a grounding that goes nowhere is as good as no grounding at all. This could even start in your plug, if it has a loose grounding wire; or it could be anywhere along the line really.

ps

Quote:

Originally Posted by thejag

and just to dispel a myth its the current that kills not voltages....

That is in fact correct yes I believe

The theory and so technicalities of it I've never been very good at I'm afraid.

thejag · Oct 10th, 2009, 02:02

sorry about the buzz thing... incorrect word usage i guess.... i guess then that the charger is malfunctioning... you can look for indian Ipod adapters which have 3 pins....

hmmm... wierd... well im off to sleep will break my head over this another day....

crvlvr · Oct 10th, 2009, 02:57

the problem of shocks that is being described here stems out of a "weak neutral" What that means is that the neutral wire, which is supposed to return the power to the grid has higher resistance than normal. When that happens, the residual voltage in your appliance increases. BTW, the problem becomes worse in 3 phase circuits. As multiple phases use the same neutral, of the neutral begins to fail to return electricity properly to the grid, the voltage across the pins can go up significantly.

You can test by seeing if the neutral wire shows any voltage before or after your device is plugged in. If so, then the neutral wire connections/joints need to be examines -- all the way back to the post if necessary.

In any case after I rambled on I decided to google and voila! found some info that probably explains the whole situation better

http://en.wikipedia.org/wiki/Ground_and_neutral

Oct 9th, 2009, 16:37	#1
konnichiwa Member Join Date: Oct 2009 Location: New Delhi/Bay Area Posts: 6	Two-pin devices leak electricity? Some of my US electronic devices are two-pin devices (e.g. Dell laptop charger, iPod charger), but are rated 110-240V so I can plug them in to Indian sockets with just a flat-pin to round-pin plug convertor. However, I noticed that these devices leak electricity when connected at my home (in central New Delhi) and office (Noida) - a USB cable attached to my laptop has given me a mild shock. I asked my local electrician to check out the "earthing" of my home electric panel and he says that he's done what he can - the problem will not occur with three pin devices, but persists with two-pin devices. It's interesting that the same problem exists at my office, but all devices at work are three-pin in any case. I guess I can try and buy and fit three-pin plugs to my two-pin devices & figure out how to ground the two-pin, but I am curious to find out if anybody else has faced this problem in India. Could be a potential hazard, especially if you have little children around. Thanks!

Oct 9th, 2009, 20:01	#7
dillichaat Professional cynic Join Date: Sep 2008 Location: जोर बाग़,New Delhi Posts: 431	OK guys, I know nothing about electricity but I can confirm that whenever I plug my macbook (aluminium body) directly in the mains, I get shocked. There actually is current running through the bloody thing! If I put one of my power strips between, no problem. Don't understand how that can be though. If the wiring in the building is not grounded and allows a current to flow through the laptop body, then how can the problem go away when I use a power strip?? Anyway, it has no adverse effects that I can notice on the laptop. Still think it's poor design, though. You shouldn't let user safety depend on external factors. __________________ When the wise man points out the black hole, the fool looks at the finger.

Oct 9th, 2009, 20:50	#9
thejag has arrived Join Date: May 2009 Location: Chennai Posts: 842	urrgh.... why the hell did i not think of this before.... its not the metal case releasing current into your hands or your body... its your body discharging static electricity into the Metal cases... If the shock is accompanied by an involuntary muscle spasm then it is electrical discharge from the device into your body... thats dangerous and indicated a malfunctioning device that needs to be repaired... (this is from a quick google search) a buzz when you touch the device in question is just your body discharging static into the device... the most common way for the static to build up?????? shoes scuffing on carpets or special flooring.... and nick and mach are right about the climate, certain conditions are more conducive to this static buildup than others.... back in late 2004 the pair of shoes which i wore then with the carpets at my last work place literally made me zap everyone i came in contact with... took me a couple of weeks to figure out that the shoes were the culprit.... i feel like such a fool for not realizing this sooner.... the reverse flow! not the shoes! Indian plugs have an earthing point... and thats precisely why this is happening.... or atleast the device is acting as an earthing point and swallowing up the static.... in which case it can literally blow up.... the current can be high enough to take out certain capacitors.... PS: Dillichaat local power strips do not include an earth wire in the internal wiring... i have enough dead SMPS units to attest to it, finally wired my own extension boxes with parts from the local store, three triple socket boxes power the PC/monitor, the chargers, the STB, the ext TV tuner, the speakers and a hell of a lot more that comes and goes and not a single problem.... maybe thats why no discharge channel and no shock when you use a power strip in the middle.... no earth no discharge path??? Last edited by thejag : Oct 9th, 2009 at 20:57. Reason: PS and lots more...

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Oct 9th, 2009, 16:46	#2
traveller.1 Senior Member Join Date: Mar 2008 Location: Arizona Posts: 108	My lap top too was giving me shocks. I bought a 3 pin adapter and I no longer have elctrifying moments

Oct 9th, 2009, 18:39	#4
Nick-H This is just a cameo appearance Join Date: Oct 2004 Location: Chennai, India Posts: 36,225	Hmmm... two-pin devices, by definition, have no earth, so the earth wiring of the socket should be irrelevant. Non-earthed devices are often double-insulated so that it is not possible for live components to be touched. Your chargers/power supplies are supplying a lower voltage to your devices anyway. I'm no expert, but I would have thought that if a high-enough current is passing through your laptop motherboard to give you a shock, the laptop will fry long before you do. Mind you, one can feel quite low voltages. I notice the shock from telephone wires here --- but only when I am bare-foot. I suspect that the higher humidity, plus sweatiness, plus bare feet, makes me notice current that I would never have noticed in UK. Just theory --- if there are any experts, I'd be interested to know if there's anything in it.

Oct 9th, 2009, 18:47	#5
machadinha brother my cup is empty member Join Date: Jan 2005 Location: yörp Posts: 14,397	Me no expert either. But I think climatic conditions could matter yes (conversely, very dry conditions could be of influence I think, as in static electricity); and while it may sound a little esoteric, some people seem more prone than others to attract electric shocks, even at low voltages. Presumably something to do with personal chemistry or so. Messed-up electrical wiring to begin with also springs to mind as a cause, of course

Oct 9th, 2009, 19:13	#6
thejag has arrived Join Date: May 2009 Location: Chennai Posts: 842	The chargers convert AC into DC and feed it into your devices... what ever youre feeling is the device itself either short circuiting or malfunctioning or not being used as per specifications as the manufacturer puts it. Did you notice this sensation only with the USB cables or were there any other symptoms....with any other device or cable? the USB cables carry a 5 volt feed... but thats only on one of the inside pins which your fingers will never be able to touch. the outer metal casing connects with the shielding in the cable (if any) and which further connects to the Casing of the Laptop/desktop and will carry a current only if a short circuit on the PC side is leaking current into the casing.... or the cable is mutilated somewhere on the inside.... What nick says is correct. you will feel the current flow if you touch any exposed terminal or device bare feet.... thats how the current that enters your body flows out of it.. or if you are holding something else with the other hand that eventually touches the ground... And nick the current doesnt have to be very high to give you a shock.... all it needs to enter your body and give you a shock is a way for it to flow further away.... and just to dispel a myth its the current that kills not voltages.... hundreds of thousands of volts flowing through a human body will not harm it if the current is small enough... and if anyone wants to see this search for van de geaf generators (its been a long time so pardon the spelling mistakes if any) and you will see these generators pumping out thousands of volts (science project level) or even millions of volts and the only side effect would be your hair standing on its ends.... Oh and after all this i also recall some thing at the office... we had a directive from the technology team to every one to stop plugging their chargers into sockets meant for PCs... apparently some chargers were short circuited and the resulting feedback ( i dont remember the actual tech terms) was causing the UPS to malfunction.... we were told we could continue to plug the chargers into sockets fed directly from the mains... but not the UPS... so i guess chargers can continue to work even though they can mess up things but i think i dont recall the exact problem cause now that i read what i wrote it doesnt seem to make sense to me.... bah it was so far back....

Oct 9th, 2009, 20:04	#8
traveller.1 Senior Member Join Date: Mar 2008 Location: Arizona Posts: 108	Mine too is a macbook pro. I think that our devices are intended as 3 pin devices. The adapters that you get overseas are 2 pin and in place of the 3rd pin in the US we have a metal earthing point. Our sockets have a screw where the earthing point gets earthed. The Indian plugs do not have a earthing point

Oct 9th, 2009, 23:14	#11
konnichiwa Member Join Date: Oct 2009 Location: New Delhi/Bay Area Posts: 6	Just to clarify - it's not static. The electrician and I both tested the current flow in the USB cable with a tester (with shoes on). And the tester also tested positive for metal screws & other metal parts on the body of the laptop. And there's current on the outside of the adaptor plug that goes into the laptop. Checked the laptop with a 3-pin adaptor - no current flow. So it's got to do with 2-pin. There's no difference in results if I put in a power srip in the middle or directly plug in the adaptor. Still not sure what the solution is, other than changing the adaptor to a 3-pin (which I can do with the Dell laptop adaptor as the Indian versions are 3-pin), but what about the iPod adaptor?

Oct 10th, 2009, 00:17	#12
Nick-H This is just a cameo appearance Join Date: Oct 2004 Location: Chennai, India Posts: 36,225	Static will discharge as a shock, and that's it, gone. A buzz is not static, it is current leakage, and you can prove this by putting a meter on it. Yes, Indian 3-pin sockets have an earth pin. It may be wired. The earth wire may go somewhere useful, or it may not. My house was professionally re-wired, including lots of green-covered wires connected to earth pins. Only thing was, it didn't go to earth anywhere. I only discovered this by getting an unpleasant shock from the microwave due to a short circuit in an AC machine! An EB engineer told me that this is very common, that they just don't bother to put an earthing point. We have one now. Some of those European two-pin plugs do have an earth. I vaguely remember... a metal contact between the two pins, or on the side of the plug? If this is the case it could explain why your European power strip is taking that current leakage to ground.

Oct 10th, 2009, 02:02	#14
thejag has arrived Join Date: May 2009 Location: Chennai Posts: 842	sorry about the buzz thing... incorrect word usage i guess.... i guess then that the charger is malfunctioning... you can look for indian Ipod adapters which have 3 pins.... hmmm... wierd... well im off to sleep will break my head over this another day....

Oct 10th, 2009, 02:57	#15
crvlvr Guru Join Date: Sep 2004 Location: Hollywood Posts: 4,668	the problem of shocks that is being described here stems out of a "weak neutral" What that means is that the neutral wire, which is supposed to return the power to the grid has higher resistance than normal. When that happens, the residual voltage in your appliance increases. BTW, the problem becomes worse in 3 phase circuits. As multiple phases use the same neutral, of the neutral begins to fail to return electricity properly to the grid, the voltage across the pins can go up significantly. You can test by seeing if the neutral wire shows any voltage before or after your device is plugged in. If so, then the neutral wire connections/joints need to be examines -- all the way back to the post if necessary. In any case after I rambled on I decided to google and voila! found some info that probably explains the whole situation better http://en.wikipedia.org/wiki/Ground_and_neutral