imac computer giving me electrical shock.

Post by **mr passout** » September 22, 2014, 7:32 pm

Recently purchased imac computer from central, but now everytime I touch the metal casing getting a little tingling shock well more than a little tingle. Not static.took it back to shop, and it worked fine works ok at my friends house next door.
So there must be an earthing problem.
Any ideas on how to rectify this problem into my existing house
Earth rod?, earthing the socket where computer is plugged into.
Any suggestions greatly appreciated.
Thanks in advance.

Post by **Landini** » September 23, 2014, 7:01 am

Earthing the socket where computer is plugged into will solve the problem. You or your neighbours have a electrical problem, but this current problem will go away.

Post by **BossHogg69** » September 23, 2014, 7:46 am

a good earth and also check the polarity, I have seen many houses here with live neutrals, Thais do not seem to know about this, my house was connected to the mains by the pea the wrong way round, ie neutral live and live neutral, so swopped it in the dist board and now all ok

Post by **stereolab** » September 23, 2014, 9:15 am

Landini wrote:Earthing the socket where computer is plugged into will solve the problem. You or your neighbours have a electrical problem, but this current problem will go away.

Nice one.

Post by **mr passout** » September 23, 2014, 9:44 am

Thanks for the replies to date.
will get the sparky to check the problem out.If i can find a descent one.
the stainless steel fridge and metal casing toaster don't give me this shock.
Had an electrician last year replace my main breaker from 63 amp to 100 amp due to running several aircons at the same time.At that stage i had what is called a Safety Cut or Ground fault circuit interruptor,he said i don't need this as the individual breakers will cut out.I remember this device tripping out unnecessarily when lightning strikes where in the area.maybe since it has been disconnected i have lost my earth,hence ground fault circuit interruptor.

Post by **Shado** » September 23, 2014, 10:38 am

We had a similar issue with a microwave oven. A 2 prong (female) to 3 prong (male) adaptor fixed it. If your computer already has a 3 prong connection then, obviously, that isn't the problem.

Post by **glalt** » September 23, 2014, 6:13 pm

My desktop computer also gave me shocks. The house is wired with no ground. (two wires). Rather than go through a lot of trouble, I bought a ground rod, hammered it into the ground outside near the computer, drilled a small hole through the wall, ran a ground wire and attached it to the computer case. Problem solved.

I have another ground rod outside the bathroom. It is used for the electric shower heater and washing machine. Anything I have wired is three wire on another ground rod. Outlets are for three prong plugs.

Post by **mr passout** » September 24, 2014, 9:13 am

Thanks for the advice so far,i just tried it every where upstairs,and no problem with shock,and also one powerpoint downstairs where my tv is connected was also fine.
The rest of the power point downstairs in office and kitchen,give that little tingle.
Like you said Glalt i think i will drill small hole and attach to copper rod that is outside where my shower heater is earthed,should also be able to earth just that actual socket,by running an earth cable from the back of the 3 pronged outlet and then running that to my shower heater earth rod.

Post by **glalt** » September 30, 2014, 10:22 am

I actually have four copper plated ground posts at our house. One on each corner of the house. I chose to do it that way to eliminate all the long ground wires if I had used only one post.

Post by **glalt** » September 30, 2014, 10:36 am

As a side note, a friend of mine recently built a new house. He has all three wire outlets. He chose to use the steel roof trusses for a ground point. I was a little skeptical but I checked his outlet voltage with a multimeter and touching the line wire to the ground it showed safe. I had never thought of doing it that way.

Post by **mr passout** » September 30, 2014, 11:41 am

Tested my computer upstairs and every socket came back with no shock(strange) also under near TV.
I decide to run an earth from the back of the 3 pin socket,and connected to the Earth of the shower rod,and all is fixed.
Still don't know why some sockets gave out a shock while the ones upstairs where fine.

Post by **Barney** » September 30, 2014, 12:19 pm

MMmmm

Some weird fix it's for perceived dangerous situations. Especially around your shower systems.
Do any of you posters so far have an electrical background to go with your advice or remedies?

Mr Passout, you had the main breaker changed by a sparky, whom it seems, disconnected or changed you earth leakage system. Then in the next breath you want to find a sparky who is decent. If the first bloke wasn't decent you should get the next decent one to recheck his work and advice provided. The earth trip mechanism was not put in the distribution board just for show, if your main board has an earth connection to a rod outside then it is your last resort safety device. The individual circuit breakers will not trip for earth leakage as he wrongly advised, they will trip for over current and short circuit situations. If you get hooked up then it will not trip, you will just shake a lot till you are gone.
Usually when electrical tradesmen start their course they are asked what is the most important wire in any system? Answer is the earth or ground.
As for your computer, is the mac a laptop? If so then it will be powered from the wall plug through a transformer and should not have 220v direct into the computer. Read the voltage label on the black box in the lead and it will tell you what the laptop input voltage is.
Please guys don't play with your electrical systems, get it checked professionally. Think of your family and little ones if not for yourself.
I have said this before, the next person who is bought back to life after dieing from electrical shock will most likely be the first. Your heart will die.

Post by **rjj04** » September 30, 2014, 1:31 pm

If I were you I'd put the GFCI breaker back in. If you don't have room in your box then Global House sells four socket plastic CB boxes for 199THB. Get an electrician - who actually understands the difference between a normal CB and an RCCB/GFCI breaker, unlike your last "electrician" - and put the GFCI in the new box in the circuit after then main shutoff switch and before the existing CB box.

About the PC, I had a desktop in my old house that used to give me a slight shock. The old rental house did not have three prong grounding sockets (ie, no earth ground in the house). Moving to my new house that has 3 pronged/earthed sockets, the PC no longer gives shocks. The new house has RCCB CBs. So, either the RCCB doesn't work (it tests okay), or the PC leak is less than the 30ma trigger level that shuts off the RCCB. I suppose if I get a few more devices that leak to ground then it will be a constant problem with the RCCB CB.

An aside...
A few days before moving to my new home we had thee A/C units installed in the house. The next morning after installing the A/Cs I noticed that the RCCB had tripped off. Later I noticed that two A/C units would not power up. Apparently my neighbor, about 80m down the road got a direct lightning strike on his house which blew out his TV and a few other things... but nobody hurt thankfully. It turned out that one A/C unit had a blown circuit board (a 500 THB repair) and the other had a fuse blow out. Although the RCCB tripped the other CB's did not. A surge in voltage will not trigger the CBs to trip. I had, previous to this lightning strike, asked my electrician to install whole house surge protectors but he said he could not find them. I planned on putting them in myself at a later date... so much for my timing.

If you do buy a cheap box and put the GFCI back in, I'd buy a surge protector and stick it in the box as well, like this one...
http://www.ebay.com/itm/2P-10-20KA-Din- ... 9426&rt=nc

It "might" help stop damage due to lightning strikes... of course a close strike and all bets are off

Post by **mr passout** » October 1, 2014, 11:05 am

The last sparky who came out,could not find a ground wire running out the main circuit box,hence him saying your GFC will never properly work anyway.
I understand that i said, but if i don't not have ground,why when the fish pond pump was faulty the GFC would cut out,and when lightning close by it may cut out also.
Cut out when had Garden light and moisture from the heavy rain would get in between the cover and bulb,the only reason is to turn everything of and see what trips it out.also he mentioned something like dimmer switches put small loads on the GFC and the something small can cut out the GFC,i don't know i am confused,different sparky's different opinions and ideas.
I sort of understand that the main breaker switches will only cut out due to overload or faulty appliance(i hope i am correct on that)
But a safety cut or GFC will prevent or cut out from electrical shock,especially like mentioned above with the fish pond or kids and water near sockets and so on.
as you can see by the photos this is the computer with the earth wire coming from behind the socket,then drilled a small hole in the wall and fed it to the pre existing copper rod where my upstairs shower heater is connected to this rod down in the ground.Thanks for all advice so far,and i will get another sparky to hook that safety cut back on,even if it trips out inadvertently,it only takes one-time.
Thanks to all,by the way i sent you a pm barney.cheers