Home user, very concerned over middle east wiring safety

[msdunkel]

Good day,

I recently moved to Abu Dhabi from the United States. Abu Dhabi has what I imagine to be a very bad copy of the British electrical system, my home has 240v 3 pronged outlets. I have a variety of electrical equipment; some can accept 110v-240v, some can only accept 110v - 120v.

I decided to try and make things a little easier by installing 2000w 240v to 110v transformers throughout the house but I'm having some trouble. The transformer has a typical US-style 3 prong plug. When I plug that into a 3 prong British style adapter the transformer runs fine; however, the instant I plug anything into the 110v transformer output (even something as benign as a simple surge suppressor) it takes the house's main electric panel offline -- not just the individual plug' circuit, but the circuit breaker for the entire floor.

I tried to use the European style 2-prong adapter instead of the 3-prong British adapter and I'm able to run pretty much anything off the transformer now. The down side to this is I'm pretty sure I've defeated the ground in the system since anything I plug in now delivers a mild tingling when metallic parts are touched. I can even daisy chain the tingle through speaker wire, HDMI, and all kinds of other cables I never thought carried much electricity .

This leads me to 3 questions:

1) Any idea why the 3 pronged Brit adapter causes the entire panel to shut down on me when a 2 prong European style works fine?

2) Working with the 2 prong European style adapter, am I in any real danger of electrocuting myself, or am I limited to these slightly painful electrical tinglings I've given myself over the past couple days?

3) Am I going to damage sensitive electronics (Denon receiver, Paradigm speakers, desktop computer, LCD TV, Blu-Ray DVD player) by having this rampant power running around?

I've been running my computers and monitors on this goofy setup for a couple weeks with no issues unless I inadvertently brush up against a metal part of the case. I only post now since I was very surprised to get a really strong tingle from simple speaker wire when the only connection those wires had to electricity was wall (power) -> transformer (power) -> power strip (power) -> blu-ray player (HDMI) -> amplifier (speaker cable) -> speaker. Items in parenthesis delineate the connection between components.

Thank you for your time.

 

[WDMDL]

Firstly, Yes. You have defeated the earthing (grounding) which is to put it politely, NOT GOOD. Possibly could be lethal in case of a fault.

Do you have access to any test equipment, even a simple multimeter?

I'm intrigued as to why the transformer would have a US style plug, if the primary was 240V.

It is possible that your transformer has some interconnection with earth/ground, and/or is an autotransformer rather than an isolation transformer.

As the "live" side of what you have at the moment is working, there is obviously an issue with earth leakage (ground fault current) rather than overload.

I reckon the cases of your equipment will be live at 120V AC though, so you need to find out what's going on with the transformers.

STOP USING THEM WHILE YOU'RE STILL HERE TO UN-PLUG!

By the way, how big and heavy are these "2000W" transformers?
Please post the make/model

Simon.

 

[pushrod]

Good day,
) it takes the house's main electric panel offline -- not just the individual plug' circuit, but the circuit breaker for the entire floor.

.

Thank you for your time.

Is this circuit breaker actually an rcd with a little (yellow?) test button with something like "30mA" amongst other things written on it?

 

[msdunkel]

Firstly, Yes. You have defeated the earthing (grounding) which is to put it politely, NOT GOOD. Possibly could be lethal in case of a fault.

Do you have access to any test equipment, even a simple multimeter?

I'm intrigued as to why the transformer would have a US style plug, if the primary was 240V.

It is possible that your transformer has some interconnection with earth/ground, and/or is an autotransformer rather than an isolation transformer.

As the "live" side of what you have at the moment is working, there is obviously an issue with earth leakage (ground fault current) rather than overload.

I reckon the cases of your equipment will be live at 120V AC though, so you need to find out what's going on with the transformers.

STOP USING THEM WHILE YOU'RE STILL HERE TO UN-PLUG!

Simon.

I think I've got a multimeter somewhere in my toolbox.

The transformer has a US style plug since it goes both ways so to speak. It can input any standard setting between 110v and 240v, and output standard setting from 110v to 240v. Since I purchased the item on amazon.com, I have to assume their primary audience is Americans who have returned to the US who want to use the equipment they purchased overseas. It can be found at this link: http://www.amazon.com/gp/product/B000MXW85A/ref=oss_product

So if I understand you correctly, you think the main problem lies in the circuitry of my transformer? I had thought that could be the case, or some gross error on the electrician's part since just about everything else in my villa is very poorly constructed.

As an aside, this country has major issues getting qualified labor, I had a fix-it man stop by the house to do some window work (leaking). He had a drill that had a power cord duct taped to another cord duct taped to another, and finally ended in 2 bare wires. He then took a screwdriver and jammed it into the ground portion of the outlet, and put the bare wires into the other two holes. Drill seemed to work and he didn't die, but it was pretty dodgy IMO.

 

[msdunkel]

Ooh, one other thing I forgot to mention. When I use the British style 3 prong adapter on the transformer, the transformer does not even need to be powered on to take down the house electricity. With transformer off, I tried plugging in a simple power strip (as well as regular electronics) and the instant the plug touched the outlet the house power popped off.

 

[msdunkel]

Is this circuit breaker actually an rcd with a little (yellow?) test button with something like "30mA" amongst other things written on it?

The switch is blue, and is completely separated from the rest of the circuit breakers on the panel (it is at the bottom). In addition, all the circuit breaker switches run horizontally while this one actuates vertically. There is also a blue button right next to it that has the letter "T" on it, which I can only assume stands for test.

 

[pushrod]

Reckon you have an earth/ground fault on your transformer.

 

[WDMDL]

WITH THE TRANSFORMER UNPLUGGED but switched ON at it's front panel

Check input voltage tapping is set for 240V

Check Ground continuity between input plug and outlet.

Check for continuity between input and output "live" terminals, you'll know them as "hot".
If you get continuity, it's an autotransformer.
If you don't, it's an isolation transformer

Check for continuity between input (hot or neutral) and ground (on the plug pins) Continuity=bad

Check for continuity between output (hot or neutral) and ground - at the 110V socket. Continuity=bad

If nothing untoward shows up here, some live tests are required and a slight error with the multimeter could kill you.

So at this point I'd get someone in who hopefully is more electrically skilled than the guy with the drill.

Simon.

 

[msdunkel]

WITH THE TRANSFORMER UNPLUGGED but switched ON at it's front panel

Check input voltage tapping is set for 240V

Check Ground continuity between input plug and outlet.

Check for continuity between input and output "live" terminals, you'll know them as "hot".
If you get continuity, it's an autotransformer.
If you don't, it's an isolation transformer

Check for continuity between input (hot or neutral) and ground (on the plug pins) Continuity=bad

Check for continuity between output (hot or neutral) and ground - at the 110V socket. Continuity=bad

If nothing untoward shows up here, some live tests are required and a slight error with the multimeter could kill you.

So at this point I'd get someone in who hopefully is more electrically skilled than the guy with the drill.

Simon.

Simon,

Thank you for the detailed trouble shooting steps. It is getting late here and I will accomplish these tomorrow and report back. I did want to add that I've got 3 of these transformers and they all exhibit identical behavior, so I would be very surprised if it was a fault in the transformer. Possibly a design flaw, but 3/3 with the same fault would lead me to believe the guy with the drill helped assemble my transformers.

Mike

 

[Engineer54]

In the Middle East, many countries use both 380/230v and 230/127volt supplies (not sure about Dubai) the 230 volt, can in the latter instance be provided by 2 phases and an earth. So first check that your wall outlet supply is single phase 230v or 2 phase 230v You can check with your multimeter between earth and each side of the two horizontal outlets on the wall outlet. ....if you get around 120v from each, then you have a 2 phase system. Check that the transformer can accommodate a 2 phase 230v input??

The other thing with these types of transformers, there is usually a voltage input selector on the rear, It maybe a switch, or a jumper type bridge plug....make sure you select the correct voltage band.

As suggested earlier, it may be prudent to find an English speaking qualified electrician, who will/can check out your problem and advise you accordingly....