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Dear Friends,

I have an HP 42" LCD TV bought from Costco 2 yrs ago that we had been using in Bangalore since Jan 2011. Until today I did not have a voltage stabilizer so connection was simply Wall > Voltage Converter > Surge protecting power Strip > TV. Since people were suggesting stabilizer and in last 5 months my printer went bad, iron went bad and phones are not charging very well, I suspected voltage fluctuation. To protect my TV and entertainment system first, I got a V Guard voltage stabilizer especially for LCD TV. As soon as I plugged it in (Wall > Voltage Stabilizer > Voltage Converter > Power Strip > TV) ... TV went phutttttt and breaker for the entire apartment got tripped. I could smell that specific burning odor that comes form circuits. The very thing that I brought to protect my TV, damaged it :angry:. Tried to hook up the TV in the old way (without stabilizer) and breaker for the apartment trips. I have no idea what went wrong, is the stabilizer not of right kind or something else. Following are some details, any pointers why this happened and what can I do with the TV, will be of great help for me and hopefully for others in future.

Voltage Stabilizer (That blew the LCD TV)
Make: V-Guard
Model: VG Crystal (specifically for LCD TVs)
Capacity: 2 A
Input Voltage: 230 V, Single Phase AC, 50 Hz

Voltage Converter
Make: GT (bought in A to Z appliance store in Atlanta)
Capacity: 1500 W

Power Strip / Surge Protector
Make: Belkin
Maximum Load: 15A, 125 V ~60 Hz, 1875W

LCD HD TV - 42"
Make: HP
Model: SL4282N
Power Rating: 120 V, ~60Hz, 300W

One doubt I am getting now is could the capacity of 2A for Voltage Stabilizer be too low? Power strip had TV, DVD player (22W), Sony receiver (265W) and Wii connected but none of them were powered on. I simply hooked up thing like this: Wall > Voltage Stabilizer > Voltage Converter > Power Strip > TV and turned on the Wall switch and TV blew off :(. Any help will be truly appreciated. Thanks!

Vishal

OP,
"entire apartment got tripped" = short circuit in your entire setup. And the circuit path happened to include your TV as well.

One theory why that would have happened is this :-

http://www.gson.org/stepdown/

Before powering on a setup like step down transformer + 110 power strip with surge protector check to see (or use a qualified electrician) with a multimeter if the voltage between output's neutral and earth lines is 0. There is a 50% chance of this not happening and the solution is simple - reverse the polarity of the plug on the wall.

If none of this makes sense - welcome to India, spend twice the money (or scale down) and get the tv locally that plugs straight to wall and has couple of years of warranty to boot.

In his case, his TV has gone kaput. If the problem is as described above, then replace the surge protector /power strip with a new one and follow the precautions suggested before you hook TV to the output to avoid the 220 volts to the varistors. Try checking the output voltage first with a multimeter. Ideally then you should look for a true step down transformer with two isolated coils instead of one coil tapped midway.

If that is not the problem and the TV is actually damaged, then chances are that your TV received the 220 volts - hopefully not. If the TV did receive 220 volts then ofcourse you will have to get the TV fixed and once you do that, you still want to make sure that you do not have the type of problems described in the post above or in the link provided in the post above. Best is to get a true step down transformer.

Vishal,

How did this episode end? Did you get the TV/Stabilizer/transformer etc fixed? What was diagnosed as wrong in the end?

I would try Wall -> UPC backup power unit from India which also has stabilizer -> Converter -> TV. Be cautious as some converters act as both 110 to 220 and 220 to 110. If you put them in 110 to 220 mode and connect them to 220v input you will end up getting 440v which will instantly destroy your appliance. Vguard works well for more forgiving appliances like fridge etc.

Dear All:

Thank you so much for replies and useful advice. After watching the thread for a few days after posting and not seeing any replies I did not check until today (had not subscribed to get email notifications).

Current Status
Took the TV, converter and stabilizer to a recommended electrician. Basically the MOV was burnt in the power supply of TV, shorting the circuit hence tripping the breaker of apartment. An MOV (metal oxide varistor) is used to protect electrical circuits against voltage surges, which suggests that the TV did get 220V. The electrician could not give me the root cause. He replaced the MOV in the TV and now the TV is working as before (Wall > Converter > Surge Protector > TV), he charged Rs 2000. I have given the stabilizer back to the shop and they are going to take it to V-Guard. If I find anything, will post it here.

What could have happened?
I think the link shared by shku2005 has the clue. Looks like my TV's power supply has that extra varistor between ground and neutral that got full 220V, I can verify this with the electrician. But why it got full 220V from the converter? ... Here is a theory .... my converter's plug has only 2 pins (its a 3 pin type plug but top pin for the ground is not there, not sure why, see attached pic), and when I plug it to the wall's 3 hole socket, polarity is fine but when I plugged it into the stabilizer which had only 2 hole socket, I would have done the opposite way and polarity got reversed creating following condition as described in the link above.

"What's worse, even though the voltage between hot and neutral on the output side is the desired 110 volts, the voltage between neutral and ground will be 220 volts if the power plug happens to be plugged into the outlet the wrong way"

[ATTACH=CONFIG]3293[/ATTACH], [ATTACH=CONFIG]3294[/ATTACH]

One thing I am not sure why didn't my Belkin surge protector have any issues. May be it doesn't have that extra varistor that gson mentioned in the link above. I am still using the surge protector.

Possible Conclusion
If the above theory is correct, this means, even now without stabilizer if I plug the converter into the wall the opposite way, it's going to blow up my TV again. Wow what a risky situation!

If anyone has any suggestion on how I can safely verify this, using multimeter or something, let me know, would love to do that.

Hope this thread helps others to save their appliances and lives actually. Basically one lesson would be, when using step down transformers, polarity of the 2 pin plug matters so don't plug it in anyway if not sure.

This means that your transformer is not a true transformer but a tap transformer, with a single winding.

Get a true transformer with double winding. Then you need not worry about reversed pins.