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Getting a tingle off all my metal frame appliances?


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Posted

You say your an electrician so I'll use technical terms.

IMHO, Your "neutral is above "earth" potential. I suspect, because you do not have a good earth, possibly none.

Or/Also, because the "star point" in 3 phase generated systems which is normally earthed at the supply/generated end, and is the "neutral" at your end, can cause this if, the 3 phases are unbalanced (excessive current flowing in one or two of three phases compered with third) then you will have current flowing in the "neutral", hence putting it above earth potential. So when you touch a grounded appliance, your in fact connecting to the neutral, and if you also touch true earth, then you are in fact connecting to the "above earth potential/voltage" of the neutral, and the true earth which is at zero voltage. Hence the "tinggle", or little shock.

You say your water heater does not give you a tingle/little shock. So I would suggest you first check you have a good earth at your end. Also then check (you say your an electrician) the voltage between your earth and your neutral.. It should be close to zero, if much higher (enough to give a title) then get the local electrical authority to remedy it, as you/they have an unbalanced load which is significant.

Sorry if I have not explained this well. Best of luck.

I am an electrician. Don't need to keep saying it :-) I haven't worked as an electrician for 20 + years. Basically finished my time. Did some appliance repairs and went into sales. That out the way...

Take my laptop for example. There is an Australian 3 pin plug on it. To test something out I plugged it into a Thai adapter which accepts the Oz three pins, but only two male pins to plug into the Thai outlet...ie there is no physical connection to the home earth system (if there was one) so while I'm sure it's possible there is a back feed from the neutral to the earth, there is no way it's getting to the frame of my laptop.

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Posted

You either have no earthing or MEN or your neutral cables are loose,easy to check if you are an ex sparky,remember to turn power off first .All the best.

read above
Posted

Take my laptop for example. There is an Australian 3 pin plug on it. To test something out I plugged it into a Thai adapter which accepts the Oz three pins, but only two male pins to plug into the Thai outlet...ie there is no physical connection to the home earth system (if there was one) so while I'm sure it's possible there is a back feed from the neutral to the earth, there is no way it's getting to the frame of my laptop.

Please read post#5 again whilst considering that one side (probably -ve) of the PSU output is likely connected to the (floating) supply ground pin.

Then look harder for a 3-pin adaptor, but you'll still have a grounding issue, have you tried any of the temporary solutions proposed yet?

Posted

Take my laptop for example. There is an Australian 3 pin plug on it. To test something out I plugged it into a Thai adapter which accepts the Oz three pins, but only two male pins to plug into the Thai outlet...ie there is no physical connection to the home earth system (if there was one) so while I'm sure it's possible there is a back feed from the neutral to the earth, there is no way it's getting to the frame of my laptop.

Please read post#5 again.

understand that Crossy. I used the 2 pin adaptor on purpose so I was sure there was no feed coming in the earth. It's all gone off the rails as usual. Rubber thongs and Mats? <deleted> :-(
Posted

In my house, in some places there were three pronged sockets, but in most places (including the bathrooms and the utility area with the water pump and washing machine) they were only 2 pin sockets. I was also occasionally getting similar small shocks off of various metal cased appliances around the house and I called in a electrician to assist. We confirmed that in most cases, even where the 3 prong sockets were there, the ground was not connected. In fact, in some places the wire was only 2 conductors, not 3... In other cases, the ground wire was connected in the socket, but the other end was not earthed anywhere.

It's not my house, so I just had him run a ground wire along the existing 2 conductor wire where needed and then had him actually tie that all together and EARTH all of it. Problem solved. Can't remember the cost as was several years ago... but I think it was in the 4-5k range.

The guy thought I had lost my mind. He thought was a waste of time and money, but he did what I asked.

Posted

I think its fair to say just because a house has 3 pin outlets doesn't mean there is an earth wire connected or even if there is doesn't mean they go anywhere past the earth link at the box, same as mine. I only have 3 earth wires, twisted together and without solder going into the earth link and nothing going from there. Could be 3 power circuits or only three earths going any where but in any case theres no wire going from the earth link to outside or to the neutral link.

I might get my test lamps out tomorrow and whip around the outlets and test between active and earth. That will tell me if theres any sort of earth connection there. The landlord wont do anything and like I said the box is in the middle of the house, bottom floor with no accessible ceiling without running a bare cable across the ceiling and out the window. I'll work something out.

I'd hate to be buying one of these ready to go farang homes here. The quality of everything is deplorable. Looks a million dollars from the outside but showers leaking internally, wiring is a shambles, cement crumbling and reo rust spots coming through the paint. Much of it would be structurally very hard to get to.

Posted

Hi OP.

If you are in a typical Thai dwelling with tiled floors you are lucky because it's only the poor conductivity of the tiles stopping you from copping an electrocution.

Posted

Enlighten me. How is this advice potentially dangerous?

Fo so many reasons....Say someone or someone with small children comes to visit. You see my point?

A ludicrous thing to say and even more ludicrous to try and defend.

Posted

Anything with a metal frame so there is obviously a major fault in the home wiring. I'm certain there is no main earth connection and who knows if some idiot has connected the earth to the neutral, have mixed polarities etc in another area of the house. Still find it hard to believe all these appliances would have some "normal" earth leakage. In any case I cite the example of my notebook because it is plugged in with a 2 pin plug ie no earth connection so no connection from frame to mains. It has to be a fault from within the machine. Maybe as others have said capacitance to frame bleed or something

Posted

All due respect but how many electrical appliances do you have with a metal frame?

Similar in my house with a sandwich toaster and exposed metal on the fridge.

My solution is to not touch the sandwich toaster when it's plugged in. General advice for an metal appliance. TIT

Fridge isn't a problem with a mat in front of it. Despite ridicule from the padantics.

My small children are perfectly safe thks.

Posted

All due respect but how many electrical appliances do you have with a metal frame?

Similar in my house with a sandwich toaster and exposed metal on the fridge.

My solution is to not touch the sandwich toaster when it's plugged in. General advice for an metal appliance. TIT

Fridge isn't a problem with a mat in front of it. Despite ridicule from the padantics.

My small children are perfectly safe thks.

fridge, microwave, washer, benchtop oven, notebook. Not really the point
Posted

best bet is try putting in your own earth spike outside in your garden and longer the better

The only problem with this is getting a decent Earth spike. From my experiences the rods are usually just copper clad aluminium and they corrode in a short time. I put two groups of 3 rods, 2 metres in length at opposite corners of our home about ten years ago, they were joined together in a triangle pattern, 3 rods connected together at one diagonal of the house and thre more at the other diagonal. We had perfect grounding (with a ground tester) for about 5 years, then they just rotted away.

I posted recently about a CTEK charger that I have that seemed to be giving all of the metal frame of my motorbike an AC charge of anywhere between 33V and 130V AC when I held my multimeter lead in one hand and the other lead to anywhere metal (ground) on my motorbike. No real answers as to what was happening there. but the CTEK had a 3 pin, and was connected to yet another 1 metre earth rod sunk 1 metre deep into the concrete / sand / soil flooring - another Earth that used to work and now doesn't!

Get a good Safe-T-Cut, it will save your life when it comes to the crunch - I somehow managed to get 230V into my teeth while trying to use them as a wire stripper - not at all pleasant, but the Safe-T-Cut did what it was designed for. Good luck!

Posted

If it's not the point. How do you open the fridge door?

plastic handles same as the microwave and washer. It's wen u brush up against it
Posted

Two things:

1. House electricity is not properly grounded...

2. You may be standing on a concrete floor...place something on the floor (like a throw rug)...to help keep the tingles down while you work on the grounding problem...

Good Luck!

Posted

Anything with a metal frame so there is obviously a major fault in the home wiring. I'm certain there is no main earth connection and who knows if some idiot has connected the earth to the neutral, have mixed polarities etc in another area of the house. Still find it hard to believe all these appliances would have some "normal" earth leakage. In any case I cite the example of my notebook because it is plugged in with a 2 pin plug ie no earth connection so no connection from frame to mains. It has to be a fault from within the machine. Maybe as others have said capacitance to frame bleed or something

I had similar problems when our place was wired by Thai electricians (On their mother's side) - we had some neutrals wired to live and some lives wired to neutral, we were getting weird junk out of some of our sockets, like 130V etc. Nightmare on Somchai Street! Then we had the local EGAT come out doing some work on the high voltage cables outside on the street when they installed a new step down transformer - They reconnected everything but had the polarity reversed, live became neutral and neutral was no live!

I have a three pin socket in my kitchen that no one uses, I have it marked with indelible ink as to which terminal I neutral and which one is live - everytime EGAT fiddle around on our road I like to double check as you never know what to expect - At least they cannot change my Earth to live or neutral!

Posted

Only concerning to your last question; i had a power book and a windows laptop leaking, now problem, real low voltage, some prickling, some surprise effect, but not hurting (i don't care about earthing, i use circuit breakers, worked well for the last 20 years, only a modem once retired after our power lines got stroke by lightning).

Posted

I have read about this type of activity but never been attracted to it. Girls still do it for me. Oh, sorry. Thought we were discussing something else... whistling.gif

Posted

Just hijacking this tread don't wont to open another one

I have a electric hot water storage system for my shower

all pipes are plastic from the system to the shower

can I still get zapped ?

Of course. You are wet and standing in water. If the case of the electric HWS is live and you touch it as in when you go to fiddle with the temperature you will compete the circuit. ZAP!

Posted

Only concerning to your last question; i had a power book and a windows laptop leaking, now problem, real low voltage, some prickling, some surprise effect, but not hurting (i don't care about earthing, i use circuit breakers, worked well for the last 20 years, only a modem once retired after our power lines got stroke by lightning).

Circuit breakers are typically 20AMP and primarily to protect the premises wiring from overload not protect from electrocution.

If you are the part of the circuit and all the current is running through you, you will have to carry more than 20AMP before the breaker trips out. 5KW. You are toast.

Only a correctly wired RCD (Residual Current Device that senses leakage to earth) will protect you but they do nothing without the electrical installation being properly earthed.

Posted

As so many have suggested on here it is a grounding or earthing issue, depending on which part of the world you are from, the biggest problem I have seen in Thailand is that most of the electrical appliances are sold with a German or European style plug commonly known as a Shuko, this is a round plug with 2 prongs and the earth or ground is a metal strip on the top and bottom that when placed in a Shuko socket connects the ground, presuming you have a ground or earth in your fixed installation.

The problem is that I have not seen any Shuko style sockets in Thailand, they are more like the sockets or receptacles that are used in the States, therefore when you plug them in the ground or earth is not made and you get earth leakage that builds up and dissipates through anyone that touches it, what I have done is bought 3 pronged plugs from Home Pro or the likes, cut off the Shuko and refitted the correct plugs to all my metal appliances, fridge, washing machine, microwave etc. and problem solved.

Posted

Just hijacking this tread don't wont to open another one

I have a electric hot water storage system for my shower

all pipes are plastic from the system to the shower

can I still get zapped ?

Of course. You are wet and standing in water. If the case of the electric HWS is live and you touch it as in when you go to fiddle with the temperature you will compete the circuit. ZAP!

Thanks mate

I have been using the shower for a few years while I was in Thailand

but I am worried now since I have not been for a while but I guess

it's time for me to die anyway whistling.gif

Posted

Generally Thai electrical work ... esp. earthing/grounding ... is a joke. Even in upscale 50M baht houses.

In both my Thai houses I've had a European electrical engineer friend inspect all of my electrical work and, as expected, it was terrible. E.g., chaotic use of color-coded wiring, loose connections, improper electrical panels and circuit breakers .... and the grounding rod was a 1-meter piece of rebarb with a thin copper wire twisted around the top.

My friend spent three weeks .... and I spent a lot of money ... fixing all this. We replaced the rebard with a 2cm-wide, 2-meter-long solid copper rod with a thick copper grounding wire that was fused to the rod with high heat.

BTW, leaking and tingling electricity can be other things besides bad grounding.

Posted

Probably a tedious task to locate but with the habit in thailand of dualing lighting circuits with appliance outlets somewhere there is a cross over between the phase and neutral and a lighting circuit is the source when on. As mentioned somewhere above the changing of the non phase/neutral specific plug in socket can sometimes remedy the problem. Also indicates the earth is non existant/ connected apart from specific unit.

If your rental building is newish then PEA regs should apply despite th N/E link. In old installations?......

Also consider electro statics if the "tingle" is non continuous. Some aircon systems can cause electrostatic charges of considerable effect.

Posted

MEN-connection is for civilized countries with certified sparkies and real world authorities!

In Thailand I have experianced MEN connection as life threatening, as neutral and live is often interchanged by misstakes or stupidity. Happend to us whan as a tree fell over the power lines to our house (2 black wires) and the house keeper sent for repairmen from the local authorities.

Of course they interchanged neutral and live, so if we had a MEN connection in our fusebox, all 'grounded' appliacies including the shower water heaters chassie would have carried mains voltage!!

I have used TT(Terre--Terre) connection with separate ground rod from the beginning (10 yers now) without any problems, even when the N/L was interchanged.

As a ground rod corrodes very quick if youre running ground fault currents through it, a MEN connection with ground rod is is not trusted by time.

As an other member here wrote, the thai fix in saving money by taking electricity between live and ground outside the meter, worsens the problem with neutral floating above ground.

I have 11 Volt low impedance on the incomming neutral!

Also as a normal ground rod can not be trusted to blow a 20 Amp fuse, a RCD device is mandatory to any installation.

However, I run my fridge and freezer outside the RCD, as it released some times from lighting strikes in the neiburhood.

.

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