Electrifyed Computer Case/tower

[BoomBoom]

as per the topic, how normal is it to have a permenant charge running through the computer case, mebbe 12v or so? Not 100% sure wether its down to the total lack of earthing or bad build?

Pretty sure it doesnt do any real damage as I've been running mine like it for 6 months now and only the PSU has blown...

Is there anyway of earthing a computer on the 12th floor of a block of appartments?

Cheers for any replys..

[kabal1234]

My computer has the same behaviour, but I've had no problems thus far so I've never bothered to deal with it further.

Yes, it's an earthing issue... I'm sure some people around here will give you suggestions on how to do it.

[BoomBoom]

I read somewhere about driving a metal stake 6ft into the ground, but in the middle on BKK and on the 12th floor above a pool, it isnt exactly an option

[kabal1234]

Hey, read this

Grounding/Earthing

[lopburi3]

If you live in a newer apartment you should have grounded electric outlets (three pins). If so just be sure to use a real grounded outlet strip (three pin plug as well as outlets) if you do not plug computer directly into wall outlet. Computer should have three pin plug unless someone cut it off.

If you do not have ground on electric lines perhaps there is one at air conditioner an electrician could tap into. Or exposed rebar in elevator shaft?

[Abandon]

It is not so improbable to lay your own earth wire. wire - no need for flexible variety, is cheap and easily chucked out the window. Use a copper stake - all hardware stores have them. just hammer the stake into the ground and connect the wire. You can do this from very high up.

Umm, however your wall socket will have three pins and the odd one is an earth. You might be saying duh right now, but some people .... ahh the stories I could tell.

If your UPS plugs directly into the wall with a three pin plug then it is already earthed. just run a wire from the com case to the UPS case, wrapped around one of the screws.

If you use an extension cord with multiple sockets you will have to open it up to see if the earth wire is connected. Many cheap extension sockets have the third earth hole but no wire connected on the inside. A good extension multi socket will have the earth wire included - thus anything plugged into it will be earthed providing the machine itself has the earth wire included.

Best thing to do is make sure the UPS goes in to the wall directly or through a three pin socket extension which has the earth wire inside. Make sure the computer is connected to the UPS via a real three wire lead. A work around is to put a wire from com case to UPS case if your power supply only runs 2 wires.

Now Sulaphat will feel his skin crawl at this.... hehehehe

You can connect the earth wire to the plumbing at the sink or water pipes as these are always earthed. No it is not dangerous, but the building owner might not like the idea.

It is a very cheap and nasty building however that does not have the third pin at the wall socket earthed.

[Axel]

If you do not have ground on electric lines perhaps there is one at air conditioner an electrician could tap into.  Or exposed rebar in elevator shaft?

<{POST_SNAPBACK}>

Tks Lop, this puts my mind a bit at ease.

I always had the problem of light shocks when touching the computer box.

My local expert ran a hole through the wall, connected the CPU with the aircon unit outside of the window, magic or not, no more shocks.

Lat week I had a power surge in the appartment (8th floor, 13 years old) rnning all appliances on 380 V instead of 220.

Surprise, after initial fear and susequent testing all computer parts survived.

Not so the UBC-box and the TV, not talking about some neon lights in the kitchen .

Oh well... houseowner assured me, this never happend before.

[paulfr]

You say you have a permenant charge on your computer.

Do you mean you can feel a shock when you touch the case ?

If so, this is not right. You may not know it, but 110VAC can kill

you very easily.

First, disconnect any wires that connect to anything out of your

room like a telephone line to your modem or another computer

that is part of your LAN.

Once you have isolated your computer, do you still have this

shock when touching the metal case ?

If so, then you have a bad Power Supply that is failing to

isolate the primary from the secondary.

Go get a new one. They are not expensive and easy to take

out and replace. Just carefully write down and label all connections

before unplugging the 3-5 cables from the supply to the rest of

the computer.

Forget about stakes in the ground. The ground for any system is

the largest conductor available .... as we call it in the industry,

the largest source of charge. Radio stations put metal meshes in

the ground to create is large dipole for better signal transmission.

Unless you have a network of equipment in many rooms of a building or

buildings, you need not worry about earth grounds.

95% sure you just need another Power Supply.

I am an MSEE with 35 yrs experience.

[kabal1234]

I'm no MSEE but I have to question your advise paulfr. I'm 100% sure my PSU is ok and I feel a slight current running through my box. I've had this in every apt I've lived in and every machine I've had. I've put this down to the fact I have no earth pin on my power outlet.

[Firefoxx]

What I've always recommended is to use a rug. Not necessarily floor to floor carpeting, since a small rug at the computer is more than enough. The rug prevents current flowing to the ground, and therefore you get no more nasty shocks from your computer. I haven't been shocked by my computer in a looooong time.

Your PSU might have blown because of an unstable power line. Either get a UPS or a power line conditioner. My PSU's have all died because of PSU fan failure (and the resultant overheat of the PSU). The "made in china" fans on 300-500 baht PSUs die really quickly.

[Thetyim]

I agree with Kabal, I have had to earth the case of every computer I have had in thailand and had to do the same for my friends.

I suspect that a new PSU will have the same problem.

Personally I think that this charge is coming from the monitor in most cases but that is only a guess.

[lopburi3]

What I've always recommended is to use a rug.  Not necessarily floor to floor carpeting, since a small rug at the computer is more than enough.  The rug prevents current flowing to the ground, and therefore you get no more nasty shocks from your computer.  I haven't been shocked by my computer in a looooong time.

Your PSU might have blown because of an unstable power line.  Either get a UPS or a power line conditioner.  My PSU's have all died because of PSU fan failure (and the resultant overheat of the PSU).  The "made in china" fans on 300-500 baht PSUs die really quickly.

<{POST_SNAPBACK}>

Still better to ground it and computer will work better also as modems are especially affected by poor grounds helping them become radio receivers.

I cut metal near center of PSU fan and pulled out the cotton plug - add a little oil - put plug back and has been running more than a year with no more noise. It was starting to sound like a truck before I did this.

[BoomBoom]

beauty cheers 4 the help.

It is a new appartment, less than a year old.. The UPS is plugged into a 3 prong wall socket, I also have a 5 socket extension that is full and its only a 2 prong into the wall. 4 of the things that are pluged into the 5 socket are connected 2 the computer in some way, maybe there providing some sort of feedback?

Problem is tho, its only the computer and monitors that are 3 prong plugs themselves, the others are only 2 prong, is there anyway of dealing with this as surely an earthed 5 prong extension is useless without the things plugged into it earthing back 2 it?

I also get a shock when for example I attach a camera 2 the computer via USB, the attached camera when touched is also electrifyed

By the sound of it a good electrician is the way 2 go before anything else blows up..

thx

[Abandon]

It is a new appartment, less than a year old.. The UPS is plugged into a 3 prong wall socket, I also have a 5 socket extension that is full and its only a 2 prong into the wall. 4 of the things that are pluged into the 5 socket are connected 2 the computer in some way, maybe there providing some sort of feedback?

If the extension block only connects to the wall via 2 prongs then your system is not earthed. I mentioned this already. Buy an extension block that has the earth wire inside it. As I said - make sure you open it up to see the wire is there because many will have the earth prong without it being connected up. Any local hardware store will have such an extension block.

I'm sure you don't need an electrician to do this.

The shocks are most likely static build up - not serious shorting out in the hardware - if the shock is just once when you touch the case and then not repeated for a while it is just static and a basic earthed plug extension will solve the problem immediately. If you find your fillings glowing EVERY time you touch the case then start changing hardware. You could also test this by sticking a light bulb in your mouth and then grabbing the computer and the nearest earth.

[paulfr]

"You could also test this by sticking a light bulb in your mouth and then grabbing the computer and the nearest earth. "

I do hope you are kidding here. This may be the funniest most erroneous comment I have read on a chat board in more than a year.

This subject of grounding baffles most professional EE's that I know.

Get an electrician to make the shocking due to your case go away.

Or take it to Pantip Plaza or Fortune IT Plaza if you are in Bangkok.

[Thetyim]

For the first time in two years I disagree with Lopburi.

The rug is not a solution it is just hiding the problem by insulating you from earth. the 'live' case is still there.

Also the rug might increase dust ingress thru the fans.

Get the CPU case earthed.

[brianbrain]

Now Sulaphat will feel his skin crawl at this.... hehehehe

You can connect the earth wire to the plumbing at the sink or water pipes as these are always earthed. No it is not dangerous, but the building owner might not like the idea.

<{POST_SNAPBACK}>

Bad advice! Most Thai plumbing uses plastic in at least some of the pipework. Although this method may work, it should certainly not be relied upon. Far better to use an existing earth known to be good, or install one of your own.

[brianbrain]

Unless you have a network of equipment in many rooms of a building or

buildings, you need not worry about earth grounds.

95% sure you just need another Power Supply.

I am an MSEE with 35 yrs experience.

<{POST_SNAPBACK}>

In my experience many (most?) PCs purchased in Thailand and used without a ground have some electrical leakage. Measured between my PC case and the ground wire, my multimeter reports 104VAC.

35 years of experience or not, I question your advice. Are you trying to tell us that we don't need grounded appliances any more? &lt;deleted&gt;! Sure his PSU may be faulty and require replacing, but this does not obviate the need for a good reliable ground. A reliable ground provides some protection in the event of a fault.

[kabal1234]

"You could also test this by sticking a light bulb in your mouth and then grabbing the computer and the nearest earth. "

I do hope you are kidding here. This may be the funniest most erroneous comment I have read on a chat board in more than a year.

This subject of grounding baffles most professional EE's that I know.

Get an electrician to make the shocking due to your case go away.

Or take it to Pantip Plaza or Fortune IT Plaza if you are in Bangkok.

<{POST_SNAPBACK}>

Dude, no offence, but I have to question some of YOUR advice in this thread.

Get (or TRY to find) a GOOD electrictian.

DO NOT take it to Fortune or Panthip cause you'll really see the sparks fly then.

"You could also test this by sticking a light bulb in your mouth and then grabbing the computer and the nearest earth. "

who said that? I love it! I'm gonna try it as soon as I get home... lol

[Sulaphat]

Now Sulaphat will feel his skin crawl at this.... hehehehe

You can connect the earth wire to the plumbing at the sink or water pipes as these are always earthed. No it is not dangerous, but the building owner might not like the idea.

<{POST_SNAPBACK}>

Actually, I would encourage a tenant to make sure that his or her electrical appliances and computer equipment had proper ground wires, i.e. three prong plugs to reduce the possibility of a fire or electrical shock. Both my residence and my rental property have three prong outlets that are properly grounded.

I have lived in apartments and houses with the old two prong plugs and have recieved the shocks from appliances that come from such wiring. I would certainly recommend to any tenant living in an apartment or house that was ungrounded to find a proper grounding solution. With the landlord's permission of course! This is particularly true for people with children, who may be more severely shocked at lower voltages.

Your solution using the sink or water pipes would in most other countries be ok, but the problem is that in Thailand so much of the plumbing is PVC pipe that it is unlikely that this solution will give a good ground. In colder climates, an alternative is to ground to a radiator pipe. Not an option here, I'm afraid.

[lopburi3]

For the first time in two years I disagree with Lopburi.

The rug is not a solution it is just hiding the problem by insulating you from earth.  the 'live' case is still there.

Also the rug might increase dust ingress thru the fans.

Get the CPU case earthed.

<{POST_SNAPBACK}>

I agree with you and that is why I said it should be grounded (earthed). The quote was the bit about a rug (and although not a cure it is a good idea in general to avoid bare feet on cement/tile when operating electrical equipment).

[Abandon]

The light bulb idea was mine kabal. Unfortunately, as with lots of my 'posts' someone took it seriously. Read through

http://www.thaivisa.com/forum/index.php?showtopic=19928

right to the end for some serious duh...

Now I'm not going to duh.. anyone, but as for plastic water pipes - anyone connecting an earth to a plastic pipe does not deserve a computer or a water supply. If it is a metal pipe (not painted duh..) (ahh the duh.. just escaped my keyboard) then errmmm the water will carry it to earth. Duh...

Ahh that duh.. just escaped again. Just in case your water supply is completely isolated, then simply run the tap at a steady stream while your computer is on, through a hose into the garden if necessary.

Now, please say RED backwards.....

[Abandon]

Mary had a little lamb

she tied it to a pylon

40 000 volts went up its arse

and turned its wool to nylon

[Thetyim]

pandit35 is so correct he should get a meddle, ehh sorry medal.

Why don't we get member Xbusman to help here, he was a good conductor.

[waldwolf]

I suspect there's more here than meets the eye.

The tower case is "grounded" internally at many, many points. Therefore if your "feeling" slight shocks by touching the case, and this was caused by a poor mains plug ground, at 220vac your playing with a potentially lethel situation. Also, if that were the problem, I'd be surprised if your CPU and most of the mother board IC's haven't already been "fried". Unplug everything and have a professional check your electrical outlets for proper grounds. The problem could be just the one outlet your using, or in your apartments individual fuse box or possibly the whole building itself.

Have you tried another outlet, either in another room or preferably at a friends home? Do you get the same "shocks"?

(PS - Before you try grounding the case, make sure you have a flashlight and fire extinguisher handy, as on attaching the ground, you may hear a big bang and find yourself sitting in the dark with your hair on fire. )

[Thetyim]

I do not know how bad the original posters problem is but from the numerous times I have had to deal with this I have found that it is only a 'small tingle' and not enough to register on an AVO meter but enough to light up a neon tester.

Shocks always feel worse when wearing no shoes and on a tiled floor which is often the case in thailand.

Having a professional check for proper grounded sockets would be a waste of time in most houses as they are only on a two wire system.

It is very simple to run a single wire from CPU case to ground.

I use a metal water pipe as it runs close by, but every telephone line has a good earth stake attached to it where the line enters the house.

[grahamb]

Having a professional check for proper grounded sockets would be a waste of time in most houses as they are only on a two wire system.

<{POST_SNAPBACK}>

Is it possible to easily check if the 3rd hole is properly grounded? I finally found a suitable 3 prong extension cable so my UPS is now plugged into a 3 prong socket (which conveniently is on the wrong side of the room from the UPS...) After reading this though, I'm not confident that I've fixed all my potential problems!

[lopburi3]

Having a professional check for proper grounded sockets would be a waste of time in most houses as they are only on a two wire system.

<{POST_SNAPBACK}>

Is it possible to easily check if the 3rd hole is properly grounded? I finally found a suitable 3 prong extension cable so my UPS is now plugged into a 3 prong socket (which conveniently is on the wrong side of the room from the UPS...) After reading this though, I'm not confident that I've fixed all my potential problems!

<{POST_SNAPBACK}>

You should have a Volt meter to (safely) check it and they only cost about 300 baht in blister pack at Tesco Lotus. You should see the same voltage between hot and earth as you do between hot and neutral. Home Pro type place may have dedicated testers which would be even easier but have never checked for them.

[Abandon]

Why don't we get member Xbusman to help here, he was a good conductor.

Good advice from Lopburi. But the problem is not usually the earth at the wall plug (good to check though) but the earth wires in the extension sockets you use. If the UPS goes directly to the wall ok, but if it goes via an extension lead then this might well not be earthed even though it has the earth pin. You have to open the extension sockets and check there is a wire running from the third pin in each plug away through through the cable. Also check the computer to the UPS is a 3 pin wire.

[kabal1234]

Having a professional check for proper grounded sockets would be a waste of time in most houses as they are only on a two wire system.

<{POST_SNAPBACK}>

Is it possible to easily check if the 3rd hole is properly grounded? I finally found a suitable 3 prong extension cable so my UPS is now plugged into a 3 prong socket (which conveniently is on the wrong side of the room from the UPS...) After reading this though, I'm not confident that I've fixed all my potential problems!

<{POST_SNAPBACK}>

Dude, this is really a job for an expert... If you really want this resolved, call someone who knows all about this stuff (see my first post in this thread for leads).

Personally, I've just learned to live with this extraneous voltage. Nearly every Thai I know has the same thing, but I understand your concern.