Earthing to stop 'live' computer case

[makecoldplayhistory]

My computer case and any metal peripheral gives a small but unpleasant shock.

The plug and socket are only two pin. I've tried rotating the plug 180 degrees having read online that it can help, but it didn't.

I have one of these things below. Not 100% sure what it is.

Someone suggested I post in the DIY section of the forum for specialist advice.

One reply suggested an isolation transformer. I have a powerful PC - the internal power supply is 1KW. Any idea where I can get the transformer (I live in Kok Kaew, Phuket).

Someone else suggested having an electrician fitting a 3 pin socket and having it grounded. Is that an easy / cheap job for an electrician?

Someone else suggested a copper wire from the case to a copper stake hammered into the ground. That is pretty do-able as the computer is on the ground floor of my (landlord's) house and close to an external door and window.

Would one of these plugs, then the wire to the outside stake work?

All and any advice appreciated.

Thanks,

Mike

Edited November 12, 2013 by makecoldplayhistory

[wayned]

The copper rod would be the cheapest and fastest and will work!

[Crossy]

Yup, a local rod hooked to that earth adaptor would do the job perfectly. A relatively short rod (1m) would kill any tingles dead

Do ensure that all your leads between the adaptor and computer are actually 3 core, far too many look like grounded leads but have only 2 pins connected

[lopburi3]

He said the plug was only two pin (hard to believe if a normal desktop) so that adapter is not going to work unless plug (and maybe wire is changed). You should be able to attach the ground wire directly to the chases of the computer at one of the screws holding case together if you really do not have a three wire cord/plug out from computer

[makecoldplayhistory]

The cable going to the computer's power supply is very heavy gauge, 2 pin (just checked).

At the moment, I have 2 2-pin sockets at the wall. Into them I have 2 pin multi-plugs and into the multiplugs I have the various plugs for the computer.

Can I use this between a (2-pin) multiplug and the wall, connecting the loop on the orange thing to an earthing rod outside? Would that not work?

I'm doing my best not to be stupid here

Thanks

[lopburi3]

No that would not work. You would have to have 3 conductor wire from computer to plug and a three pin plug to use that socket/plug adapter to ground. The easy way is a wire from case screw to ground rod outside into earth.

[makecoldplayhistory]

I'll do that then. Thanks lopburi (and others).

[wayned]

He said the plug was only two pin (hard to believe if a normal desktop) so that adapter is not going to work unless plug (and maybe wire is changed). You should be able to attach the ground wire directly to the chases of the computer at one of the screws holding case together if you really do not have a three wire cord/plug out from computer

Actually the two pin plug out of the desktop is not hard to believe. The electrical cord connected to the desktop has a 3 pin socket on one end, but a two pin plug on the other. They sell them that way in the local computer shop like that because nobody where I live has grounded 3 pin outlets. In the boonies, anything is believable! Drive the rod in the ground and connect it directly to the case screw as stated above.

[technologybytes]

Pulling the plug and rotating 180 degrees sounds stupid, but often works. However if you have a printer or monitor attached then the "tickle" could be coming from them via the metal case on the computer as they will be grounded to each other.

Really all you need to stop the tickle is a wire from the case of the computer to a real ground, ideally a copper rod sunk in the ground. If the case is at the same potential as the ground then it should be impossible to get the tickle.

[Carl64]

An uninterruptible power supply UPS fixed my problem . Also good for unclean power and surges. My UPS plugs into a 2 pin unearthed socket.

[bangkokheat]

make sure your power plug is firm in the power point, if it is loose you will get a shock/tingle, i haver seen this many times and experienced it myself, not many plugs fit well in power points here

[sawadeeken]

UNTIL YOU GET IT FIXED....... DON'T be barefooted on a tile floor when you could possibly touch it, even accidently...........

[Andre0720]

If I were you, I would just get used to these small electrical shocks...

They go through the adaptor, which gives you a nice jolt of less than 20 volts...

Less of a thrill than having a cute Thai girl take your breath away...

It's the easiest...

[camo007]

Same issue in my office then i discovered the building had no green earth cable!

[Eagleizer]

The cable going to the computer's power supply is very heavy gauge, 2 pin (just checked).

At the moment, I have 2 2-pin sockets at the wall. Into them I have 2 pin multi-plugs and into the multiplugs I have the various plugs for the computer.

Can I use this between a (2-pin) multiplug and the wall, connecting the loop on the orange thing to an earthing rod outside? Would that not work?

I'm doing my best not to be stupid here

Thanks

Be aware that if you ground your computer, you will still have to pay for the electricity that is going into the ground

I use a plastic mat that I have my chair and feet on. Looks something like this:

http://www.amazon.com/ProSource-Multitask-Polycarbonate-Carpets-Hardwood/dp/B00E9EBPYS/ref=sr_1_3_m/181-6308567-4217959?s=office-products&ie=UTF8&qid=1384256889&sr=1-3

(sorry, I don`t know where you can buy in Thailand)

You could also just put some tape on the areas you accidently touch. Last time I had this was with my laptop where I

got electricuted in the ear by my ear phones/buds. You`ll NEVER get`s used to that burning feeling as some suggested...

[Kerryd]

I had the same problem before and the suggested fix was a (quality) UPS. Not only grounds everything plugged into it but gives you that extra bit of time to save/shut down stuff during the all-to-frequent power outages. Heavy little sucker but better than getting shocked all the time (while sitting in my chair, barefoot on recently washed tile flooring) !

[RichCor]

The 'tingle' can go above 20v.

When working at a radio station, I went to switch out an serial-data peripheral cable on a pc and got hit with the full voltage when I tried to disconnect it from the case. I put it right back quick. Someone had stretched the power cable sideways enough that the neutral was no longer making a contact at the power socket and the equipment was pulling voltage over the 30' peripheral cable's ground shield.

Higher voltage can and will go to ground, though you, if the path offers less resistance than the neutral side of the circuit.

When I traveled through Laos the guesthouse in Luang Prabang gave me a pillow to put under my feet. Oh, thanks.

I think the better suggestion as has been made is to run a nice size wire from a computer case screw to a copper ground rod into the actual earth. Make sure the wire makes good contact with the metal case, and is connected securely to the copper rod with a tap or pressure screw. Remember to keep the ground around the copper rod damp/wet.

Edited November 12, 2013 by RichCor

[makecoldplayhistory]

I think I'll do the cable-to-copper-rod method.

Need to hang 46 picture frames tomorrow. I'm sure I'll run out of screws / rawl plugs or something at somepoint so will get the rod and wire then. Next job is working out how to get the wire to the outside...

I'd only ever touched the PC barefoot on a tile floor but it's not much more than an unpleasant tingle really. I have a nice mechanical keyboard that I use for typing but a metal Apple Mac one I use for coding. If it wasn't for the Mac keyboard being unusable, I wouldn't bother doing anything about the earthing.

Thanks for all of your help.

Edited November 12, 2013 by makecoldplayhistory

[silent]

The cable going to the computer's power supply is very heavy gauge, 2 pin (just checked).

At the moment, I have 2 2-pin sockets at the wall. Into them I have 2 pin multi-plugs and into the multiplugs I have the various plugs for the computer.

Can I use this between a (2-pin) multiplug and the wall, connecting the loop on the orange thing to an earthing rod outside? Would that not work?

I'm doing my best not to be stupid here

Thanks

If nobody already said, as far as I recall Canada outlawed these things years ago to protect people whose only knowledge of ground is what they walk on, so they don't become one. Either get used to the slight buzz like I've had to and be careful with a bit of knowledge, or not.

[makecoldplayhistory]

How are those things dangerous Silent?

I can wire a plug...

Edited November 12, 2013 by makecoldplayhistory

[jackflash]

The OP should understand that there are two types of appliance:

Firstly there's normal metal-bodied devices which are intended to be used with an Earth connection. Without an Earth connection, the suppression caps in the power-supply cause a small earth current to flow, and this is what causes the tingle. The best way to fix it is to fit an Earth wire as described above.

More modern devices are Double Insulated. They have a plastic case so you cannot touch metal and are intended to be used with a two pin cord (eg no earth).

If your appliance has a three pin input connector, it should always be used with an earth connection.

There should be a special symbol on the case if it's Double Insulated. It's two squares one inside the other.

Edited November 12, 2013 by jackflash

[RichCor]

How are those things dangerous Silent?

I can wire a plug...

In the US, these are known as 'cheater plugs'. If a power socket had a metal enclosure AND a a third-wire running back to a ground-buss/ground-rod then the center faceplate screw could be used with this 'adapter' to convert the 2-pin outlet to a 3-pin grounded outlet.

Unfortunately, many people erroneously use these as '3-pin to 2-pin' power adapters causing the device 'ground' connection to go nowhere (float). If a hazard situation occurs where potentially lethal voltage is transferred to the metal frame and now a lack of a grounded connection prevents the voltage being safely carried away then anyone/anything touching the frame becomes a potential voltage transmission conduit. (ie, I touch the malfunctioning leaking washing machine while barefoot, so long farang cash cow).

[jobsworth]

all computer power supplies are switch mode.

the older ones have a slightly live case unless your condo has an earth.

Most condos do not have an earth and it is expensive to provide an earth.

the newer power supplies do not have a slightly live case.

So the cheapest solution is to buy a new power supply at about 500 to 800 THB.

It is the box screwed at the top of the case where the mains lead plugs in.

Of course then you have to fit it which is not that difficult.

Hope that this helps.

[Timwin]

You can make a better earth by digging in garden a ditch, getting a few concrete blocks or pouring wet concrete into it. Then use 1-2 meter copper rod to connect to the concrete and cover the ditch. This way is used in dry places like desert to make an earth. In a condo a few small concrete blocks and a copper wire to those in balcony will get rid off the shocks but it is not a proper earth but better than nothing.

Edited November 12, 2013 by Timwin

[jacko45k]

Is it a one-off shock, or is it continuous?

I would just like to eliminate static as a possibility.

Other than that a wire from the computer case to some ground point is needed.

Therein lies a question....

From the picture it doesn't look like a 3 wire system... although you do have earth leakage protection....screwed up to it's maximum setting.

Finding a 'grounding point' to connect to....

Do you have an electric shower......?

[makecoldplayhistory]

We have electric showers in the house.

It's a continuous shock. A pretty mild one. Just enough to stop me tyoing on a metal keyboard. For everything else, it's not really a problem.

all computer power supplies are switch mode.

the older ones have a slightly live case unless your condo has an earth.

Most condos do not have an earth and it is expensive to provide an earth.

the newer power supplies do not have a slightly live case.

So the cheapest solution is to buy a new power supply at about 500 to 800 THB.

It is the box screwed at the top of the case where the mains lead plugs in.

Of course then you have to fit it which is not that difficult.

Hope that this helps.

It's a house not a condo and a power supply to run my PC would cost $230.

Thanks

[shaurene]

It is quite common sometimes you can get a little shock touching your car but you say your computer uses internal 1kw that is 1,000 watts. I made sure all stuff in my home that uses high enough watts is earthed, if your computer has a 3 pinn socket hole it is there for an earth, also make sure your showers are earthed if you have electric water heaters in there.

[makecoldplayhistory]

It is quite common sometimes you can get a little shock touching your car but you say your computer uses internal 1kw that is 1,000 watts. I made sure all stuff in my home that uses high enough watts is earthed, if your computer has a 3 pinn socket hole it is there for an earth, also make sure your showers are earthed if you have electric water heaters in there.

It came with a heavy duty cable, a kettle plug for the computer end and a 2-pin for the wall.

Like this

And here's the power supply.

Thanks

[Crossy]

It came with a heavy duty cable, a kettle plug for the computer end and a 2-pin for the wall.

That is NOT a 2-pin plug, it is a Schuko or Euro plug, it may have 2 pins but the important ground is made by the side contacts or the hole in the plug (dependant upon which European country you're in).

You can buy the correct cable to plug into a Thai 3-pin outlet at any computer store, that's not going to help since you don't have 3-pin outlets

Easiest solution is earth the case to a spike in the garden.

Better solution is to get the proper cable and use the adaptor shown earlier connected to a spike in the garden.

Yes, there is a technical difference between those two solutions.

It is important to understand that the ground on a standard PC PSU is a functional ground, it is required for the unit to function correctly. Specifically it is required for the mains inlet filter to work (it's the filter that produces the leakage that bites). Without a ground you get the tingle, but you also leave your machine open to noise from the supply which may cause malfunctions (it's not a surge arrestor, you also need one of those, and it needs a ground too).

As to your water heater, is it grounded?

[makecoldplayhistory]

No idea about the water heater.

I've never felt any kind of tingle. Is there any way I can find out?

My landlord seems very good but lives in Bangkok; I've never met him face to face. I also don't know if he's have any idea about anything technical about the house.

Thanks