Electricity (and Shocks)

[Felix-451]

Late on Friday night, my electricty blew.. I'm not sure exactly what happened but I was plugging something in to an extension cord, (and I have about five of them, with probably too much stuff plugged in, but I only have two mains sockets in the room, so I thought of it as a necessary evil.. now I'll just unplug everything I'm not using), and the fuse blew on the mains socket, and gave me a little shock, down the line..

Fortunately, I was OK but lost electricity in the room for the last two days (I imagine the circuit breaker was engaged, although I know almost nothing about these things). The engineer just came and repaired it, and as far as I can work out, everything is fine. But now I'm afraid of using this plug socket again, how can I test it without fear of electric shock? Apparently, I've been told it's quite a common occurence in older buildings, and that mains sockets are generally not grounded. Actually, a 2-pin plug cannot be grounded, can it?

I've been used to the little sparks when plugging things in, usually. But this was literally, a big shock..

[Guest Reimar]

First thing at all is: Grounding!

If your room has 2 Pin plugs only, you don't have any grounding! May you room is not high above the ground so you can do a grounding by yourself. Buy for about Baht 100 in an Hardware shop a Copper stick for grounding and place this stick in the soil! Afix a cable from the stck to you computer case and fix it to the case.

If you have an Volt Meter, check out which wire is the Line and which the Zero. Measure between Line and Zero and you should get ~230 V, measure between Line and Ground you should get 230 V also, measure between Zero and Gound you should get 0 V. If you get between Line and Ground let say 190 V, you will get between Zero and Ground 40 V which is the difference between 230 V and 190 V and it shows you that the Grounding isn't working.

If you check without Grounding from Line to Case you will get less than 230 V and the missing Volts are on Zero! If yopu check you will be very surprise about the amount of Voltage on the Zero!

If the fuse was blow up, you have a realy short circuit! Check all connected devices!

[wpcoe]

First thing at all is: Grounding!

If your room has 2 Pin plugs only, you don't have any grounding! May you room is not high above the ground so you can do a grounding by yourself. Buy for about Baht 100 in an Hardware shop a Copper stick for grounding and place this stick in the soil! Afix a cable from the stck to you computer case and fix it to the case.

Is a copper gounding stake a standard item in Thai hardware stores? Admittedly I've never looked for one, but I've never seen one either.

How many condos/apartments will let you just run a wire from your unit to the grounding stake? I'm still working on finding a stealth method to use at my condo.

I'm thinking of using the wall cavity space where the water pipes run, but I need to see if it has an unobstructed path from the fifth floor (where I am) all the way to the ground, and if so, how I can access the bottom of that cavity space at ground level.

[scottie dog]

First thing at all is: Grounding!

If your room has 2 Pin plugs only, you don't have any grounding! May you room is not high above the ground so you can do a grounding by yourself. Buy for about Baht 100 in an Hardware shop a Copper stick for grounding and place this stick in the soil! Afix a cable from the stck to you computer case and fix it to the case.

Is a copper gounding stake a standard item in Thai hardware stores? Admittedly I've never looked for one, but I've never seen one either.

How many condos/apartments will let you just run a wire from your unit to the grounding stake? I'm still working on finding a stealth method to use at my condo.

I'm thinking of using the wall cavity space where the water pipes run, but I need to see if it has an unobstructed path from the fifth floor (where I am) all the way to the ground, and if so, how I can access the bottom of that cavity space at ground level.

Bet the water pipes are plastic!!!

[Guest Reimar]

First thing at all is: Grounding!

If your room has 2 Pin plugs only, you don't have any grounding! May you room is not high above the ground so you can do a grounding by yourself. Buy for about Baht 100 in an Hardware shop a Copper stick for grounding and place this stick in the soil! Afix a cable from the stck to you computer case and fix it to the case.

Is a copper gounding stake a standard item in Thai hardware stores? Admittedly I've never looked for one, but I've never seen one either.

How many condos/apartments will let you just run a wire from your unit to the grounding stake? I'm still working on finding a stealth method to use at my condo.

I'm thinking of using the wall cavity space where the water pipes run, but I need to see if it has an unobstructed path from the fifth floor (where I am) all the way to the ground, and if so, how I can access the bottom of that cavity space at ground level.

Normally all Hardware shops who dealing with Waterpipe and electro staff have this copper pins and the cost varies a little from 60 to 100 Baht. This pin ~1.8 - 2 m long and you get a clamb for twire seperate.

May you ask the Condo Manager for permission to place the Ground-Cable and explain him why and for what and last but not least for safty reason as well.

[Crossy]

I doubt this is a grounding issue, although installing a ground spike would be a smart move.

If you popped the fuse you either overloaded the strip (unlikely) or the strip has an internal short. If you're using the cheapo strips, ditch them and buy some half decent (>150 Baht) ones.

If you 'know almost nothing' get someone who knows what they are doing to install your earth

[cdnvic]

This gets discussed alot in the Building and Housing section of the forum. Have a look through there and you will probably find alot of info, much of it from qualified people.

[wpcoe]

Bet the water pipes are plastic!!!

The are, Scottie, that's why I want to run a wire down the cavity ... hence why I want check if there is any obstruction in the cavity between my 5th floor unit and the ground.

[elkangorito]

Bet the water pipes are plastic!!!

The are, Scottie, that's why I want to run a wire down the cavity ... hence why I want check if there is any obstruction in the cavity between my 5th floor unit and the ground.

Ensure that any wire/cable is run down the 'electrical riser' & not the 'mechanical riser'. If run down the mechanical riser, some mechanical 'tradesman' (I use this term loosely) may decide to get rid of this wire/cable because it's in the wrong place.

[h90]

Late on Friday night, my electricty blew.. I'm not sure exactly what happened but I was plugging something in to an extension cord, (and I have about five of them, with probably too much stuff plugged in, but I only have two mains sockets in the room, so I thought of it as a necessary evil.. now I'll just unplug everything I'm not using), and the fuse blew on the mains socket, and gave me a little shock, down the line..

Fortunately, I was OK but lost electricity in the room for the last two days (I imagine the circuit breaker was engaged, although I know almost nothing about these things). The engineer just came and repaired it, and as far as I can work out, everything is fine. But now I'm afraid of using this plug socket again, how can I test it without fear of electric shock? Apparently, I've been told it's quite a common occurence in older buildings, and that mains sockets are generally not grounded. Actually, a 2-pin plug cannot be grounded, can it?

I've been used to the little sparks when plugging things in, usually. But this was literally, a big shock..

Did you see what the "engineer" did?

That big shock, when exactly (no not the time, what you did) happen? And what did you mean with shock? Did you get an electric shock or was it a "star wars" like explosion in that plug?

What I think that the wires might short in the plug (maybe due to melting plasic, because overload).

On the circuit breaker there is a number, can you find that? if you can see your wires is there something what you can read on it?

If the the wires are on the wall and not inside, how are they mixed together (worst (and most common) solution is drill them together and put electric tape over it).

[aznyron]

First thing at all is: Grounding!

If your room has 2 Pin plugs only, you don't have any grounding! May you room is not high above the ground so you can do a grounding by yourself. Buy for about Baht 100 in an Hardware shop a Copper stick for grounding and place this stick in the soil! Afix a cable from the stck to you computer case and fix it to the case.

Is a copper gounding stake a standard item in Thai hardware stores? Admittedly I've never looked for one, but I've never seen one either.

How many condos/apartments will let you just run a wire from your unit to the grounding stake? I'm still working on finding a stealth method to use at my condo.

I'm thinking of using the wall cavity space where the water pipes run, but I need to see if it has an unobstructed path from the fifth floor (where I am) all the way to the ground, and if so, how I can access the bottom of that cavity space at ground level.

get the building maitenance man to install a ground and new outlet all he has to do is drill hole in the floor and put a metal plug with a wire attached to it for the ground and you will have a 3 way plug look like this

I I do not use those cheep extension cords with multiple outlets they will fry you computer grounding is a must for computers

O

[Crossy]

get the building maitenance man to install a ground and new outlet all he has to do is drill hole in the floor and put a metal plug with a wire attached to it for the ground and you will have a 3 way plug look like this

Er, speaking as the only "Bull Powered Member" of Thaivisa I feel qualified to comment that the above is pure Bull of the highest order.

Drilling a hole in the floor as a ground is useless, concrete is a pretty good insulator unless it's wet (then you have other problems with your plumbing). A ground MUST go to a proper ground rod buried in the ground, period!!

[cdnvic]

get the building maitenance man to install a ground and new outlet all he has to do is drill hole in the floor and put a metal plug with a wire attached to it

Dangerous advice.

If your maintnence man actually does this, don't let him work on anything electrical because anyone who knows anything about electrical safety will tell you that this will not work as a ground.

Consult an expert when dealing with power.

(edit: Crossy beat me to it )

Edited February 14, 2007 by cdnvic

[Naam]

A ground MUST go to a proper ground rod buried in the ground, period!!

*****

right you are. unfortunately most ground rods are useless during the dry season (depending on your soil) unless you (or your gardener) regularly waters the area around the rod(s).

[frenchFARANGbkk]

Hi,

I found this interesting website about grounding in Thailand:

http://www.thailandguru.com/grounding-eart...electrical.html

They say:

A ground is not any of the following:

* A ground is not a wire screwed into the wall

* A ground is not a wire stuck into the dirt

* A ground is not a wire connected to just anything metal and big

So I wonder why my washing machine has a wire screwed into the wall ?! Completely useless or better than nothing ?

Thanks.

Edited December 11, 2007 by frenchFARANGbkk

[Crossy]

So I wonder why my washing machine has a wire screwed into the wall ?! Completely useless or better than nothing ?

Completely useless

There's a major thread going in the DIY subforum, where grounding etc. has been discussed ad-infinitum, also have a look here http://www.crossy.co.uk/wiring/protection.html and here http://www.crossy.co.uk/wiring/2pin.html

Once upon a time, long ago, in a land far away (the US actually) it was acceptable to use the building re-bar as a ground, this is marginal at the best although doubtless good enough if you have and ELCB (Saf-T-Cut) installed.

Your washing machine probably has a Schuko (Euro) plug this page will show you how to connect it safely http://www.crossy.co.uk/wiring/plugs.html

Edited December 12, 2007 by Crossy

[naka]

Crossy.

Unlike most countries where I've lived, in Thailand I never see a link between neutral and

earth at the pole mounted transformer (N to tank stud to Earth), be it 1 or 3 phase. In Thailand do they make

this connection elsewhere e.g. Dist Board or simply don't bother at all ?

Naka.

Edited December 12, 2007 by naka

[Plus]

There's a leakage from my computers at home. I just got a long piece of wire and stuck the other end in the dirt outside the window. Every couple of days the soil would dry and I'd feel little shocks on some unpaited surfaces, but nothing a bucket of water splashed outside won't fix.

A couple of days ago I added a foot long metal rod and driven it as deep as possible. No problems so far.

I'm not calling it a proper ground but it serves its purpose.

[Naam]

There's a leakage from my computers at home. I just got a long piece of wire and stuck the other end in the dirt outside the window. Every couple of days the soil would dry and I'd feel little shocks on some unpaited surfaces, but nothing a bucket of water splashed outside won't fix

A couple of days ago I added a foot long metal rod and driven it as deep as possible. No problems so far.

I'm not calling it a proper ground but it serves its purpose.

a 30cm rod is a bit meager. try to replace it with a longer rod. and if you use the bucket of water add a packet of salt to increase conductivity (wisdom and experience from the african bush).

and now i'm waiting patiently for Crossy, Kangorito, various Rice, Pig and Chicken Farmers to crucify me

[Naam]

So I wonder why my washing machine has a wire screwed into the wall ?! Completely useless or better than nothing ?

what's wrong with screwing???

[Plus]

a 30cm rod is a bit meager. try to replace it with a longer rod. and if you use the bucket of water add a packet of salt to increase conductivity (wisdom and experience from the african bush).

It's not like 220v leaking from the computer, it's just a tingling sensation when I move my arm over the spot where paint peeled off my metal computer table.

Salt is a god idea, though.

I should probably insulate the power supply unit inside the box but I'm too lazy. I don't think any leakage is normal, besides it increases electricity bill.

Edited December 12, 2007 by Plus

[Crossy]

a 30cm rod is a bit meager. try to replace it with a longer rod. and if you use the bucket of water add a packet of salt to increase conductivity (wisdom and experience from the african bush).

It's not like 220v leaking from the computer, it's just a tingling sensation when I move my arm over the spot where paint peeled off my metal computer table.

I should probably insulate the power supply unit inside the box but I'm too lazy. I don't think any leakage is normal, besides it increases electricity bill.

The tingle is caused by leakage through the mains filter which is required to stop nasty harmonics getting back into the mains from your computer PSU. This leakage is quite normal and a really crappy ground will stop the tickle. The leakage is a few hundred microamps and is mainly capacitive, your electricity meter won't even notice it.

BUT

Should you have a fault inside your PSU which makes the casework fully live you will have ZERO protection from a lethal shock.

Insulating your PSU will not help and could be potentially damaging to your electronics and peripherals.

[Crossy]

and now i'm waiting patiently for Crossy, Kangorito, various Rice, Pig and Chicken Farmers to crucify me

Why should I crucify you Naam? You always talk sense

[Crossy]

Crossy.

Unlike most countries where I've lived, in Thailand I never see a link between neutral and

earth at the pole mounted transformer (N to tank stud to Earth), be it 1 or 3 phase. In Thailand do they make

this connection elsewhere e.g. Dist Board or simply don't bother at all ?

Naka.

The link 'should' always be there (grounded neutral) are you sure it's not? I try to avoid getting close enough to the 25kV incoming to see properly.

Thai regulations also now require a MEN link (ground to neutral) in your distribution board although most rural areas don't have it yet.

[Plus]

Should you have a fault inside your PSU which makes the casework fully live you will have ZERO protection from a lethal shock.

Insulating your PSU will not help and could be potentially damaging to your electronics and peripherals.

Not really zero, right, I have a crappy ground already, don't I?

The question is - do I need to ground the computer (easy enough) or should I install ground on the power outlet - lots of things plugged in there - modems, printers, phone, speakers etc.

[Crossy]

Should you have a fault inside your PSU which makes the casework fully live you will have ZERO protection from a lethal shock.

Insulating your PSU will not help and could be potentially damaging to your electronics and peripherals.

Not really zero, right, I have a crappy ground already, don't I?

The question is - do I need to ground the computer (easy enough) or should I install ground on the power outlet - lots of things plugged in there - modems, printers, phone, speakers etc.

OK, OK, ALMOST ZERO

The ideal solution is a proper grounded outlet, next is one of those 2-3 pin adaptor thingies with a ground lead on the tab, final and least preferable option is to ground the PC metalwork.

Don't forget, if you have a grounded outlet you need to ensure your power boards are the proper grounded 3 pin type, not the 'fake' 3 pin type with only a 2 wire cord.

[naka]

Crossy.

Unlike most countries where I've lived, in Thailand I never see a link between neutral and

earth at the pole mounted transformer (N to tank stud to Earth), be it 1 or 3 phase. In Thailand do they make

this connection elsewhere e.g. Dist Board or simply don't bother at all ?

Naka.

The link 'should' always be there (grounded neutral) are you sure it's not? I try to avoid getting close enough to the 25kV incoming to see properly.

Thai regulations also now require a MEN link (ground to neutral) in your distribution board although most rural areas don't have it yet.

I can see a 3 phase, about 100 kVA transformer quite clearly from my balcony, no N-E link

Naka.

[Naam]

and now i'm waiting patiently for Crossy, Kangorito, various Rice, Pig and Chicken Farmers to crucify me

Why should I crucify you Naam? You always talk sense

i don't think my wife agrees Crossy

[Crossy]

I can see a 3 phase, about 100 kVA transformer quite clearly from my balcony, no N-E link

Interesting, scary even.

There was a post a while back from a chap who evidently had a phase grounded somewhere in his building (a row of shophouses IIRC). He was seeing 220V ground to neutral and 380V or so ground to live, obviously if the neutral-ground link was fitted this would have caused some fireworks.

Sooooo, maybe we have stumbled upon a very worrying design fact.

EDIT Any of the electrical pro's seen this / comments??

Edited December 13, 2007 by Crossy

[elkangorito]

I can see a 3 phase, about 100 kVA transformer quite clearly from my balcony, no N-E link

Interesting, scary even.

There was a post a while back from a chap who evidently had a phase grounded somewhere in his building (a row of shophouses IIRC). He was seeing 220V ground to neutral and 380V or so ground to live, obviously if the neutral-ground link was fitted this would have caused some fireworks.

Sooooo, maybe we have stumbled upon a very worrying design fact.

EDIT Any of the electrical pro's seen this / comments??

I remember that one Crossy but I do recall that "we" asked for more info, which was not forthcoming. I do believe he did resolve his situation but don't recall if an explanation was given.

Incidentally, I recently did an inspection at a TV members place & discovered that his KWH meter was connected to one phase & earth. The earth cable was the topmost bare cable of the aerials. The neutral was obvious but not used (below the phase cables & insulated). This proves that his system (in his area - near Pattaya) is MEN.

And yes Naam, you don't make silly comments BUT.....

I'd be careful about using salt water to "enhance" an earth. What this will do is advance the rate of corrosion

& eventually, cripple the earth.

Edited December 13, 2007 by elkangorito