Grounding (earth?) a device that keeps jolting me.

[weltall]

For years now the antenna cables in my house would jolt anyone that would touch the metallic tip without shoes or while touching a wall. I am no electrician so I just thought its normal for the antenna to do that. So recently my new DVB-T Receiver that its cover is all metallic would do the same thing and the same thing happened if I would touch any metallic part from the back of the tv. I used a test screw driver and checked it. The TV and the dvb-t receiver even by themselves without any cables connected apart from the power would light the screw driver. Then it passed my mind about the antennas and i disconnected all the tvs and of course after that the antenna cable would not send a jolt. 2 out of the 3 tvs i have in home would make the antenna cable sent a jolt when they were connected. Btw 2 of the TVs are identical and i tested them both and the other tv is fine. I also checked different plugs in different rooms with both.

Well I do not have a big knowledge about electricity but I know that the ground (earth) is there to absorb such jolts or at least when the ground is not properly connected devices will send you jolts sometimes if they have metallic parts. So I took a cable and tried to connect all the devices on from a metallic part on them to a ground on a plug. It did work but I am not sure if this is right. Actually after connecting only the big from a metal part on its back that is for a screw to mount on a wall, all three devices (2 tvs and the receiver) do not jolt anymore. I am guessing that through the cables the extra electricity of all passes through the tv and to the ground. That idea makes me wonder if its ok for this to happen or if its going to actually harm the tv even more.

Thank you in advance for any help.

 

[malcolmsanford]

You maybe experiencing a build up of high protective currents from your appliances, and it maybe also be that you have poor bonding in the house, or perhaps even no earthing to sockets, that is causing your problem.

I'm afraid there is no easy ,,,,,,,,,,,,,,,it's such and such, you need to test your installation and see if there is an underlying problem, and I would recommend that you get an electrician in to carry out a periodic inspection report on the electrics of your house.

This is not overly expensive depending on your location a proper report will cost in the region of a couple of hundred pounds. If you post your location then I'm sure one of the local members to you would give you a PM or even pop round and have a chat with you.

 

[telectrix]

as above. it sounds like a fault on the earthing system of your installation. on older TVs, the metal chassis of the set was connected directly to the neutral of the supply. it's not so much the possible damage to the TVs you should be worried about, but the risk of injury to yourself and family. it needs an electrician to diagnose and rectify the fault, as malc. says.

 

[Knobhead]

By the way our OP keeps referring to “ground” and “antenna” I think he may me in America.

 

[telectrix]

you may be right tony, does sound like he's got excessive touch voltage. i am not familiar with the US system, is it 2 phases to provide 220V?

 

[malcolmsanford]

you may be right tony, does sound like he's got excessive touch voltage. i am not familiar with the US system, is it 2 phases to provide 220V?

Yes mate normally the states have 110-115 volt LINE/NEUTRAL and the 2 phases makes the 220v

 

[telectrix]

cheers, malc. thought i'd read that somewhere.

 

[weltall]

Thanks for all the replies No I am not American, I am Greek. We have 240V here. The thing is not all our devices here use a cable the has an earth pin

I just find it weird because the 42 inch LCD TV jolts and the 37 inch one does not. They are exactly the same model of TV too just different inches and I have tested both TV on different plugs around the house and it still happens. I will be calling an electrician to see what is there problem. Thank you very much again for all the help

 

[Engineer54]

Thanks for all the replies No I am not American, I am Greek. We have 240V here. The thing is not all our devices here use a cable the has an earth pin View attachment 7629

I just find it weird because the 42 inch LCD TV jolts and the 37 inch one does not. They are exactly the same model of TV too just different inches and I have tested both TV on different plugs around the house and it still happens. I will be calling an electrician to see what is there problem. Thank you very much again for all the help

Get your local electrician to check out your installations earthing system thoroughly. You have the added problem of unpolarized and un-earthed plug tops, so the live/phase conductor has only a 50/50 chance of being switched, on any appliance supplied by such a plug top. The other 50% of the time, the appliance will remain live throughout the internal appliances electrical circuit.

I do hope you have Double Pole MCBs/RCBOs protecting these unpolarized socket outlets??

 

[weltall]

I am not sure what a Double Pole MCBs/RCBOs but if its the circuit breaker then every room has a single circuit breaker. 2 times in my life that I got hit by electricity the circuit breaker cut off the electricity. The only 2 pole cirtuit breaker we have goes to the boiler (more like 1 single and 1 double cirtuit breaker).

Also the socket outlets all around the house though have ground with C being the ground. But of course that does not mean much since the appliance itself does not connect to it. I am going to call an electrician first thing in Monday.

 

[Engineer54]

Weltall,

That's a German schuko outlet, which has a scrapping earth connection. Unfortunately they are not polarised. DP means that both line conductor and neutral conductor have protective devices at the origin of the circuit, ie, ....normally 2 MCBs linked together as one complete MCB module.

Anyway, your doing the right thing by calling on an electrician to sort your problem out for you....

 

[weltall]

Thank you once more I hope you all have a wonderful day.