Minor shock from LED TV backpanel- what next?

[recpippu]

Just moved to Bangalore from US and I am in the process of setting everything up right from a broom.

I have a 46 inch Samsung LED TV which I brought from US. I connected it to the mains in the below sequence

240 V Mains (with earth) --> V-Guard crystal plus LCD TV voltage stabilizer --> Goldsource 500W 240 to 110 AC converter --> Belkin surge protector --> TV

I noticed that I am getting a mild shock from the back of the body, especially the screws when the TV is ON. Checked with a tester, and it lights up. Tested with a multimeter, the ac voltage between my hand and the screw is around 7-8V. (it varies in fact - It starts with around 24v when I check with mutlimeter and in the next 5-10 seconds will come down to 7-8v).

The voltage exists even if my Belkin is off ( and upto the voltage converter is live.)

Need your suggestions on what could be wrong and how can it be corrected? Is the grounding in my apartment faulty? How can I prove that to the electrician who did a very poor job is wiring this apartment (There are many switches which dont work or line/neutral reversed in some plugs, I pay rent).

Is it harmful to operate the TV in such conditions? I could see flickers in the screen when I touch multimeter leads on the screw. Since the TV is imported from US, there is no warranty for that in India.

 

[Jams4znik03]

Get a good eletrician to check the polarity of the mains terminals - Live , Nuetral. Check whether earth is actually connected or it is floating.. builders often use many of thse shortcuts. Such issues come up when the live and nuetral ar reversed as well. A simple tester can do as well. for meauring volatages you will need a multimeter. Causes for this leakage can be due to multiple reasons.. but often the manual intervention works best given the quality of the security personnel..

 

[Subcenter2009]

Try using a wire and bulb between Phase and Earth for a few seconds and see if the bulb lights up brightly. If it does not light up, then your earthing is faulty. Even improperly grounded computers give the same shock problem if the earth is not effective. Remember to always have a bulb in the circuit to prevent your main fuse from blowing. If the earthing is good then, I am not qualified to answer. Maybe a more savvy member can tell you.

 

[shanmune]

When you say that you see some voltage on the TV metal parts even after switching off the surge protector, mostly this could be the case of Phase-Netral rerversal. That is, normally you will see two pins (One phase and one Netral - in addition to earth pin) on the scoket. In general, the left pin will be Neutral and the right pin will be Phase. On your Surge protector, can you use tester and see which pin (left or right) glows on the surge protector ?
You can try these steps to test further.
1. Check which pin glows on your surge protector ?
2. Check the same on your Voltage converter, Stabilizer and finally on the main socket on your wall. If you see your left pin glowing on all the points, then it is a case of Phase-Neutral reversal. Get your electrician get the issue solved by interchanging those two points on your main socket.
3. You can also try reversing your TV plug while connecting it to surge protector and see if you get the voltage again on the TV screws.

Apart from the TV, have you connected any hi-fi equpiments (like Home thaetre systems, DVD player, etc) ? If so, try disconnecting them and test your TV again. Since you say that you see some voltage even with the urge protector switched-off, I am suspecting the pins (phase and neutral) being reversed.

Even otherwise, these modern day electronic equipments come with SMPS power supply system and these SMPS systems will generally have some volts on the body of those electronic equipments. Personally, I am not a big fan of SMPS power supply and these manufactures use that just to make their systems look slim.

 

[recpippu]

When you say that you see some voltage on the TV metal parts even after switching off the surge protector, mostly this could be the case of Phase-Netral rerversal.

Even otherwise, these modern day electronic equipments come with SMPS power supply system and these SMPS systems will generally have some volts on the body of those electronic equipments. Personally, I am not a big fan of SMPS power supply and these manufactures use that just to make their systems look slim.

I checked, and phase is on right side.
Is it ok to operate the TV under such a slight voltage on the body?

I believe it is the step down xfr. My tester glows when I check the earth pin of its 110 v socket. Also the earth to phase voltage in the 110v socket is almost zero. All 3 step downs have the same behavior.

 

[shanmune]

I checked, and phase is on right side.
Is it ok to operate the TV under such a slight voltage on the body?

I believe it is the step down xfr. My tester glows when I check the earth pin of its 110 v socket. Also the earth to phase voltage in the 110v socket is almost zero. All 3 step downs have the same behavior.

Then you should get the step down transformer inspected. What is the voltage difference between the Phase and the Neutral of the 110v socket ?

 

[recpippu]

What is the voltage difference between the Phase and the Neutral of the 110v socket ?

its 110v only.

 

[shanmune]

its 110v only.

Okay. WHen you say that earth to phase (between erath and phase on the 110v scoket) is 0 volts on the 110v supply, then you need to get your 110v voltage converter repaired. Now - you say that you get some 24 volts on your TV body for the first few secs after starting your TV and gets settled to around 5 or 7 volts. Having 7 volts is okay, but it should not have 24 volts at the beginning. I guess your voltage converter is having some problem (apart from the earth pin being at the same voltage level as the phase). If you see, most of the SMPS based systems having only two ping plug will have some voltage levels (around 10 volts).
So first get your converter repaired.

 

[baijuxavior]

IMO nothing to worry about the mild shocks. My TV has this shock when connected to other devices. I tested each device (HTPC, AVR, STB) independently and there is no shock, but when they are connected to TV there is mild shock. For example when TV is connected to AVR there is no shock. The moment I turn on the STB there is electricity leakage and you may think the culprit is the STB. But it is not the case. I switch off avr and then there is no shock. I think this is a problem with SMPS power supply of TV/STB/HTPC which have only two pins as pointed out by shanmune above. What I have done is connect a small wire from the amp body to the ups body and there is no shock now.

 

[prosenjit]

just local earth it.your whole building earthing rectification will be tough.its a clear case of improper earthing.
use any copper wire and attach it with tv body and keep the other end attached into a metal pipe which goes undrground.if that is finding a tough job...use long wire upto ground floor..attach it in common earthing plate....well a haslle job for a day..but no play with human safety.....

or use your idea...how to local earth..you have to send the elctricity at tvs body into earth...no special wire is needed..any electrcila copper wire..10 Rs meter will do...

 

[Drameri]

I have similar case.
There is crt tv by Sony ,the output and antenna socking when touched.
What I did first to remove the antenna and decoder and still doing the same .
Reversing the polarity of the tv plug.there is no sock but tv is not turning on.
What can I do

 

[Donivlapog]

I noticed Mi TV owners complaining about small earth issues in the past. Minor shocks coming from touching the TV chassis. If you wear slippers, it won't. There is a small hack for that. Use a voltage stabiliser and it will be 90% gone.