Did my washing machine just shock me?..

[cmth]

From my experience so far with Thai electrical installations, there is probably not an earth ground installed anywhere at the home. As long as 3 wires are going from the electrical panel to each socket with 3 pins, the best solution is to ground the whole electrical system. This can be done with one copper ground rod and 00 gauge copper wire. More than likely this will not be the case. Most installations have only 2 wires ran and the ground pin is a decoration. In that case the previous posts about grounding the washing machine separately would be the best solution. And to the poster who grounded his WM to the rails on the condo balcony, You are aware that any current that goes to ground by whatever fault will pass through this rail and anything else metal that it is connected to. So if a fault occurred and all 240 volts went to ground you have created a high amperage electric fence. Your neighbor goes out to look off the balcony, leans against the rail, and is instantly electrocuted. I would suggest you re-examine your "solution" before someone else pays for your mistake.

Yes be sure there is a ground installed - use a cheap multi meter in AC voltage position to confirm same 230v reading from live to neutral and to ground points on outlet.

As for the electric fence - path of electric will be to ground using path of least resistance - which will be railing rather than a person unless you have insulated that rail (electric fence makes no contact to ground). As for high amperage that is what will trip your breaker and why you have the ground path (something better than you touching and being touched).

If the washer is grounded to metal and there is a fault in the circuit that sends the voltage to the ground wire, that wire and any metal it is connected to becomes live. I'm not sure that being attached to railing that is attached to other metal in the structure by unknown means and may not connect to an earth ground at all is going to be the path of least resistance. The current flowing to un-grounded or improperly grounded ground wire does not create a load on the circuit and will not trip the breaker. A live wire being carried to to no earth ground or extremely weak earth ground is not the same as a short circuit which causes the high amperage and overloads the breaker. And yes an electric fence is grounded. The control box has a live side that supplies the current and a ground side that is attached to earth ground. When an animal, person or according the strength even a weed, touches the exposed live wire the circuit will complete. http://en.wikipedia.org/wiki/Electric_fence

Many countries have an easy solution to this problem. It is called a ground fault interrupter. Any time the interrupter senses voltage on the ground wire it will disconnect itself from the source. Theoretically you could drop a running hair drying in the tub with you and be unharmed with the use of this device. I for one will not be testing it that thoroughly.

Edited March 26, 2015 by cmth

[IMHO]

Many countries have an easy solution to this problem. It is called a ground fault interrupter. Any time the interrupter senses voltage on the ground wire it will disconnect itself from the source. Theoretically you could drop a running hair drying in the tub with you and be unharmed with the use of this device. I for one will not be testing it that thoroughly.

GFI's are old tech, superseded by Residual Current Devices (RCD's), which are readily available in TH, and protect against more than just leakage to ground - any imbalance will be detected.

Even with such devices, I can assure you, a shock still hurts like crazy, and can cause permanent tissue damage. You are less likely to die though

[IMHO]

It's been covered here before, but I still add another vote

If you have appliances with a plug like this:

They DO need a ground. To acheive that with standard TH sockets, you'll need to buy yourself some of these: http://www.directtoshop.com/webapp/wcs/stores/servlet/en/directtoshop/adapter-wa-gf%28r5b%29-wonpro-p161248

[bankruatsteve]

Many countries have an easy solution to this problem. It is called a ground fault interrupter. Any time the interrupter senses voltage on the ground wire it will disconnect itself from the source. Theoretically you could drop a running hair drying in the tub with you and be unharmed with the use of this device. I for one will not be testing it that thoroughly.

GFI's are old tech, superseded by Residual Current Devices (RCD's), which are readily available in TH, and protect against more than just leakage to ground - any imbalance will be detected.

Even with such devices, I can assure you, a shock still hurts like crazy, and can cause permanent tissue damage. You are less likely to die though

Now where did you get that? "GFI" is same technology as "RCD" - it's just called that in the states. Due to the way power is supplied in the states, a front-end RCD would not work so "GFI's" are used, usually as a receptacle, in places where fault hazard is greatest: like wet places and outside outlets.

Interestingly, GFI's are usually set to trip at 5ma versus the 30ma common for RCBO's.

[Crossy]

Yup, the only 'reserved' terminology, at least in the industry, is ELCB, this is reserved for old voltage operated units which are not permitted in most countries as they are unreliable and don't protect from direct contact shock.

Of course that reservation does not prevent the term ELCB being used on RCDs by many manufacturers of water heaters etc. Rest assured, if you have a modern 'ELCB' it's actually an RCD.

As IMHO alluded, an RCD (or whatever you call it back-home) will NOT protect you from a shock, it will REDUCE the chances of you dying from said shock. It still hurts like hell.

An RCD would not prevent the tingle that our OP was feeling, only a ground will do that.

[cmth]

Sorry, if I was implying that a GFI or RCD would do away with any shock. My intention was to add that the use of this technology greatly reduces the chance of death and a 5ma shock, while painful is nothing near a 20 plus amp shock waiting on the circuit breaker to trip. But back to the topic, yes the only way to do away with the tingle is proper grounding. With that being said there is a reason somewhere that current is leaking to the metal case. In a perfect situation there should be no current anywhere but on the proper lines. There is a defect somewhere causing this. Grounding is a solution to a problem and a safety measure, not a requirement on AC circuits. In a world where everything was wired properly and there were no defects in the components a ground wire would never see any action.

Edited March 26, 2015 by cmth

[Crossy]

The GFI / RCD or whatever does NOT, that's NOT limit the shock to 5mA or 30mA, the shock is whatever the supply can deliver into your body resistance. The RCD (hopefully) disconnects the supply before you die.

The 5mA or 30mA (or whatever) is the current that the RCD uses to decide if there is someone getting shocked or not.

Also note that many appliances (particularly your PC) have mains filters (to stop noise getting out), these are inherently leaky and float the metalwork to about 50% of mains even if these is no fault. These filters require a ground to function properly (and stop you getting bitten).

[paulchiangmai]

As said lack of earth. Washing Machines often come with Schuko plugs. These require a Schuko socket for the earth to be connected correctly. The earth is the metal side contacts on the plug. As an alternative a third pin can be added to the plug to fit a standard 3 pin outlet.

Pic of Schuko plug/socket

schuko.jpg

If anybody knows where to get this 'third ' pin, can they please advise here.

Unfortunately inserting a 'pin' in the hole of a Schuko doesn't work as the spacing is wrong to fit the Thai outlet

Only choices are - fit a Schuko outlet, use the Wonpro (or similar) adaptor, replace the plug (as noted could have warranty issues).

And yes, do verify that the ground is actually connected in the outlet.

'Do verify that the ground is actually connected in the outlet.' Is that enough Crossy? When I moved into my new house I installed an electric water heater in one of the bathrooms, three wires were protruding from the wall for just this purpose. As I trust nothing to do with electricity in Thailand I checked all three wires, sure enough there was a live and a neutral ok, also an earth that entered the roof space and went nowhere. Any so called electrician that would pull this stunt should be shot. TEST to see if the earth is in fact connected. Easily done with a multimetre and length of wire.

[cmth]

Yes. As soon as the current exceeds the threshold it disconnects the circuit therefore stopping the flow of electricity. Maybe the current is higher in the milliseconds it takes for the device to activate but we are talking milliseconds not full seconds that it would take to trip the breaker in the box, if it even tripped at all. This is off topic from the OP's problem and we agree that it is not the solution the OP's issue. So form you own opinions about GFI/RCD. I personally believe in them and think they are a great safety device. But I prefer not to ever have the need to rely on one.

[Crossy]

Agree paul, my bad.

By the way the device is a 'multimeter', a 'meter' measures things, a 'metre' is a unit of length. Except across the pond where a 'meter' is both.

[cmth]

As said lack of earth. Washing Machines often come with Schuko plugs. These require a Schuko socket for the earth to be connected correctly. The earth is the metal side contacts on the plug. As an alternative a third pin can be added to the plug to fit a standard 3 pin outlet.

Pic of Schuko plug/socket

schuko.jpg

If anybody knows where to get this 'third ' pin, can they please advise here.

Unfortunately inserting a 'pin' in the hole of a Schuko doesn't work as the spacing is wrong to fit the Thai outlet

Only choices are - fit a Schuko outlet, use the Wonpro (or similar) adaptor, replace the plug (as noted could have warranty issues).

And yes, do verify that the ground is actually connected in the outlet.

'Do verify that the ground is actually connected in the outlet.' Is that enough Crossy? When I moved into my new house I installed an electric water heater in one of the bathrooms, three wires were protruding from the wall for just this purpose. As I trust nothing to do with electricity in Thailand I checked all three wires, sure enough there was a live and a neutral ok, also an earth that entered the roof space and went nowhere. Any so called electrician that would pull this stunt should be shot. TEST to see if the earth is in fact connected. Easily done with a multimetre and length of wire.

Just curious as to why there would be a neutral wire. Everything here 220-240. There is no need for a neutral wire.

[Crossy]

Just curious as to why there would be a neutral wire. Everything here 220-240. There is no need for a neutral wire.

Thailand is single-phase 2-wire with one pole grounded at the transformer (that's the neutral).

Unlike the US which is single-phase 3-wire with the 115-0-115V transformer centre-tap grounded at the transformer (becoming the neutral).

[bankruatsteve]

To clarify, the standard for voltage in the states is 120/240v. Years ago, it was 110/220v and some places still have that. And, there's a few places that have 230v transformers. Given that, even in 120v zones, the normal household probably averages 115v. Go figure.

[cmth]

Just curious as to why there would be a neutral wire. Everything here 220-240. There is no need for a neutral wire.

Thailand is single-phase 2-wire with one pole grounded at the transformer (that's the neutral).

Unlike the US which is single-phase 3-wire with the 115-0-115V transformer centre-tap grounded at the transformer (becoming the neutral).

Ok. This is where I am getting confused. I'm only familiar with the US way doing things I guess. So in Thailand one wire carries 220-240 the other wire is neutral just like 110-120 in the US. If this is the case you could always bond the neutral with the ground inside the outlet you want grounded. While not the ideal solution, it would offer more protection than no ground at all.

[bankruatsteve]

Just curious as to why there would be a neutral wire. Everything here 220-240. There is no need for a neutral wire.

Thailand is single-phase 2-wire with one pole grounded at the transformer (that's the neutral).

Unlike the US which is single-phase 3-wire with the 115-0-115V transformer centre-tap grounded at the transformer (becoming the neutral).

Ok. This is where I am getting confused. I'm only familiar with the US way doing things I guess. So in Thailand one wire carries 220-240 the other wire is neutral just like 110-120 in the US. If this is the case you could always bond the neutral with the ground inside the outlet you want grounded. While not the ideal solution, it would offer more protection than no ground at all.

NO. Neutral is NEVER bonded to ground at the receptacle. Only at distribution points like the transformer and CU.

[cmth]

Just curious as to why there would be a neutral wire. Everything here 220-240. There is no need for a neutral wire.

Thailand is single-phase 2-wire with one pole grounded at the transformer (that's the neutral).

Unlike the US which is single-phase 3-wire with the 115-0-115V transformer centre-tap grounded at the transformer (becoming the neutral).

Ok. This is where I am getting confused. I'm only familiar with the US way doing things I guess. So in Thailand one wire carries 220-240 the other wire is neutral just like 110-120 in the US. If this is the case you could always bond the neutral with the ground inside the outlet you want grounded. While not the ideal solution, it would offer more protection than no ground at all.

NO. Neutral is NEVER bonded to ground at the receptacle. Only at distribution points like the transformer and CU.

If ground and neutral are bonded at the CU, like it has been done for many years in the US. There is absolutely zero difference in these wires anymore. They are attached at a common point and essentially all become one wire. Since there is no current running through these wires in normal operation they are not connected to any breakers. Any current that bleeds over to ground or neutral is following the same path. What are the dangers or problems in bonding at the receptacle? This is not something I would endorse but am curios as to why it is a big no no.

[bankruatsteve]

Neutral does carry current. The ground wire in a receptacle is only to provide safe conduit for faults.

You don't get a shock from neutral because it, and ground, and you for practical purpose are all at zero potential relative to live. IE: there is no reason for the electricity to choose you as the conduit.

Edited March 26, 2015 by bankruatsteve

[xylophone]

Just curious as to why there would be a neutral wire. Everything here 220-240. There is no need for a neutral wire.

Thailand is single-phase 2-wire with one pole grounded at the transformer (that's the neutral).

Unlike the US which is single-phase 3-wire with the 115-0-115V transformer centre-tap grounded at the transformer (becoming the neutral).

Ok. This is where I am getting confused. I'm only familiar with the US way doing things I guess. So in Thailand one wire carries 220-240 the other wire is neutral just like 110-120 in the US. If this is the case you could always bond the neutral with the ground inside the outlet you want grounded. While not the ideal solution, it would offer more protection than no ground at all.

NO. Neutral is NEVER bonded to ground at the receptacle. Only at distribution points like the transformer and CU.

Under the "Multiple Earthed Neutral" (MEN) system I believe the neutral and the earth are bonded at the distribution board, perhaps Crossy would like to comment on this.

Now onto the subject by the OP............ I have found that many appliances (Fridges, microwaves, ovens, washing machines etc) here have the two pin plugs, just the same as you would buy on those connected to your television or similar.

However if you look carefully at the back of these appliances there is always a screw which has the traditional earth sign on it and very often has a green earth wire attached to it or included in the packaging. It would seem as though the earthing of these appliances is not a prerequisite here, however there is provision made for it, so work that one out!

I have stopped stray voltages from these appliances by running on earth wire from this particular point, along the two core wire already on the appliance and then fitted a three pin plug, incorporating the new earth wire. It is hidden from view so no problem with it looking untidy.

And as a couple of other posters have pointed out, always good to check to see if behind your "supposed it three pin socket outlets" you actually have an earth wire connected, which was not the case in one of my houses, so I had to rectify it.

[Forkinhades]

As said lack of earth. Washing Machines often come with Schuko plugs. These require a Schuko socket for the earth to be connected correctly. The earth is the metal side contacts on the plug. As an alternative a third pin can be added to the plug to fit a standard 3 pin outlet.

Pic of Schuko plug/socket

schuko.jpg

If anybody knows where to get this 'third ' pin, can they please advise here.

Unfortunately inserting a 'pin' in the hole of a Schuko doesn't work as the spacing is wrong to fit the Thai outlet

Only choices are - fit a Schuko outlet, use the Wonpro (or similar) adaptor, replace the plug (as noted could have warranty issues).

And yes, do verify that the ground is actually connected in the outlet.

'Do verify that the ground is actually connected in the outlet.' Is that enough Crossy? When I moved into my new house I installed an electric water heater in one of the bathrooms, three wires were protruding from the wall for just this purpose. As I trust nothing to do with electricity in Thailand I checked all three wires, sure enough there was a live and a neutral ok, also an earth that entered the roof space and went nowhere. Any so called electrician that would pull this stunt should be shot. TEST to see if the earth is in fact connected. Easily done with a multimetre and length of wire.

It is easily done if you have the right equipment, a DMM will not do the job.

Measuring Za (earth rod) requires very expensive equipment

Measuring Zs (earth loop impedance) is somewhat cheaper

MEN connection is important if you want TNC type values, which would open your MCB

Obtaining the value of the earth is what is required.

[cmth]

I guess I'm still confused. In the US a CU comes from the factory with the neutral and ground terminals bonded inside the panel. To separate them you have to break metal tabs or remove metal connectors. If neutral and ground are connected at the same point in the CU then they have the same potential. There is absolutely no difference between the two. Running 3 wires to an outlet and then connecting two of them to same location basically makes a single wire with a larger gauge of the neutral and ground. Unless I'm missing something the neutral is needed to complete the circuit but the current is only on the hot wire. Anytime I've read amperage I put the gauge around the hot wire only. Like I stated before with all the neutral wires and ground wires going to the same place with no breaker, you basically have one wire for ground and neutral as far as electricity is concerned.

[Forkinhades]

Just curious as to why there would be a neutral wire. Everything here 220-240. There is no need for a neutral wire.

Thailand is single-phase 2-wire with one pole grounded at the transformer (that's the neutral).

Unlike the US which is single-phase 3-wire with the 115-0-115V transformer centre-tap grounded at the transformer (becoming the neutral).

Ok. This is where I am getting confused. I'm only familiar with the US way doing things I guess. So in Thailand one wire carries 220-240 the other wire is neutral just like 110-120 in the US. If this is the case you could always bond the neutral with the ground inside the outlet you want grounded. While not the ideal solution, it would offer more protection than no ground at all.

NO. Neutral is NEVER bonded to ground at the receptacle. Only at distribution points like the transformer and CU.

If ground and neutral are bonded at the CU, like it has been done for many years in the US. There is absolutely zero difference in these wires anymore. They are attached at a common point and essentially all become one wire. Since there is no current running through these wires in normal operation they are not connected to any breakers. Any current that bleeds over to ground or neutral is following the same path. What are the dangers or problems in bonding at the receptacle? This is not something I would endorse but am curios as to why it is a big no no.

This connection should be done before the Safety-cut device, any imbalance is measured after the safety-cut.

[bankruatsteve]

You could also put the clamp ammeter around the neutral to measure the current: live or neutral makes no difference. Put it around the ground and you will get zero. I guess I don't 'splain it very well. Crossy?

[cmth]

In the US at least putting a amp meter around a neutral will not give you a reading. I'm no trying to be difficult I really am trying to learn here.

[Forkinhades]

If it was bonded at the receptacle then the Safety-Cut device will open.

[bankruatsteve]

In the US at least putting a amp meter around a neutral will not give you a reading. I'm no trying to be difficult I really am trying to learn here.

That would only be the case in the kitchen circuit (for example) where (I think it's code requirement) to have two circuits: 1 - from the "left" live and 2 - from the "right" live with a common neutral. Then, if there are equal loads on each circuit, the neutral will have zero current.

And, if you measure the neutral at the CU, there might be same effect as above. IE: if it happens there is equal or near equal loads on the left and right live, then neutral would also be at or near zero amps at the CU.

Otherwise, yes you will get a reading on neutral and which will be the same reading as live if you measure at the device itself. I'm absolutely sure of it.

Edited March 26, 2015 by bankruatsteve

[cmth]

In the US at least putting a amp meter around a neutral will not give you a reading. I'm no trying to be difficult I really am trying to learn here.

That would only be the case in the kitchen circuit (for example) where (I think it's code requirement) to have two circuits: 1 - from the "left" live and 2 - from the "right" live with a common neutral. Then, if there are equal loads on each circuit, the neutral will have zero current.

And, if you measure the neutral at the CU, there might be same effect as above. IE: if it happens there is equal or near equal loads on the left and right live, then neutral would also be at or near zero amps at the CU.

Otherwise, yes you will get a reading on neutral and which will be the same reading as live if you measure at the device itself. I'm absolutely sure of it.

This is description I found about the US neutral and ground system. It echos my experiences with the neutral carrying current and being seen by an amp meter.

A Neutral represents a reference point within an electrical distribution system. Conductors connected to this reference point (Neutral) should, normally, be non current carrying conductors, sized to handle momentary faults (short circuits) occurring in electrical equipment. However, with the introduction of non linear loads, such as computers, electronic lighting, TVs, VCRs and other switchmode power conversion equipment, the requirements for the neutral conductor has changed (increased).

A Ground represents an electrical path, normally designed to carry fault current when a insulation breakdown occurs within electrical equipment. (Note: Breakdowns can be forced by connecting (dropping) a metal tool or conductive material from a voltage potential to the steel structure within a facility.) Connections to the electrical path (Ground) are made convenient for the installation of electrical equipment. Some current will always flow through the ground path. This current will come from a number of normal sources. Capacitive coupling and Inductive coupling between power conductors and the ground path (conductive conduit, conductive structure members, etc) are the greatest sources of ground path current.

[bankruatsteve]

In the US at least putting a amp meter around a neutral will not give you a reading. I'm no trying to be difficult I really am trying to learn here.

That would only be the case in the kitchen circuit (for example) where (I think it's code requirement) to have two circuits: 1 - from the "left" live and 2 - from the "right" live with a common neutral. Then, if there are equal loads on each circuit, the neutral will have zero current.

And, if you measure the neutral at the CU, there might be same effect as above. IE: if it happens there is equal or near equal loads on the left and right live, then neutral would also be at or near zero amps at the CU.

Otherwise, yes you will get a reading on neutral and which will be the same reading as live if you measure at the device itself. I'm absolutely sure of it.

This is description I found about the US neutral and ground system. It echos my experiences with the neutral carrying current and being seen by an amp meter.

A Neutral represents a reference point within an electrical distribution system. Conductors connected to this reference point (Neutral) should, normally, be non current carrying conductors, sized to handle momentary faults (short circuits) occurring in electrical equipment. However, with the introduction of non linear loads, such as computers, electronic lighting, TVs, VCRs and other switchmode power conversion equipment, the requirements for the neutral conductor has changed (increased).

A Ground represents an electrical path, normally designed to carry fault current when a insulation breakdown occurs within electrical equipment. (Note: Breakdowns can be forced by connecting (dropping) a metal tool or conductive material from a voltage potential to the steel structure within a facility.) Connections to the electrical path (Ground) are made convenient for the installation of electrical equipment. Some current will always flow through the ground path. This current will come from a number of normal sources. Capacitive coupling and Inductive coupling between power conductors and the ground path (conductive conduit, conductive structure members, etc) are the greatest sources of ground path current.

I must say, that is the strangest description of the US neutral and ground system I have ever seen. If you can give the source, I might comment further.

All I can say is neutral absolutely conducts current and can be measured by a clamp-on ammeter. Within the same circuit (except as I previously noted), the current in the neutral will be exactly the same as the live. That is basically how GFI's work: if there is imbalance in current between neutral and live over 5ma, it trips.

In any case, I doubt banter about US electrics is greatly appreciated in TV. Cheers.

[Forkinhades]

^ Exactly correct, the imbalance is measured after the Safety-Cut.

With 3 phase systems any current that is not balanced will flow down the neutral back to star point of th he tx, upstream of the Safety-Cut (before)

Your circuits after the Safety-Cut, will have the same flow of current in both the Live (line) and Neutral conductors. Which should be the same. This is what the Safety-Cut measures. Typically these are set to 30mA. So an indifference of >30mA flowing down the neutral will open the Safety-Cut. These can be adjusted to be lower.

Typically a current of >50mA is required to kill a human.

With Safety-Cut devices installed the touch voltage will not reach higher than 50V, without the correct earthing. With correct earthing combined with the Safety-Cut no voltage should ever be present.

[Crossy]

In any case, I doubt banter about US electrics is greatly appreciated in TV. Cheers.

Whilst interesting, we are most definitely not in Kansas, Toto.

Let's try and stay on-topic which is Thai electrics.

i.e. (Mostly) 3-phase 4-wire or single-phase 2-wire, TN-C-S with MEN, 220V phase-neutral.

[Sophon]

You use this adapter to obtain ground from a grounded Thai outlet. It will then fit your outlet shown in photo and if outlet is grounded provide a path to ground. You might want to invest in a Safe-t-cut or other brand RCCD to cut power before it can become serious. Well worth the small cost involved as too many things are subject to potential issues without.

Slightly off topic, but both of or washing machines came already supplied with three pin plugs. However, our fridge and chest freezer have two pin plugs and a separate round wire connected to the frame. Are there any adapters similar to the above, where one can insert the two pin plus and connect the separate ground wire to the ground pin?

I know I can replace the plugs, but as mentioned by others that might invalidate the warranty.

Sophon