Question for any qualified electricians living in Isaan

[Crossy]

2 hours ago, williet98248 said:

I had the same problem in my old house .  I hired a Thai electrician on a recommendation; told him I needed grounded circuits for computers and other appliances.  Expected him to rewire with three wire cable.  House was originally not grounded and two wire cable hot/ neutral wires to all sockets.  All two pin outlets.  He grounded the neutral bus bar in the box with a stake, installed three plug outlets to the two wire cable and bridged the ground screw to the neutral on each three way receptacle with a short wire.  I was skeptical but I have a plug in gadget that tells me by colored lights if the outlet is grounded, has an open or wired incorrectly.  It said all my three pin outlets were grounded and all my three pin appliances and computers are working properly with no leakage.  Never heard of such a thing.  I had him pull out the old manual reset safety cut as well and he replaced it with a digital safety cut that resets itself after a two minute delay.  So it is ready to go when the power is restored.  This after a three day holiday when I returned to find all my frozen food melted and everything in the fridges (two) wilted and no one around to reset the safety cut for the three days.  I used to get a power outages quite often even when all the houses around me had electricity.  A bolt of lightning kms away would do it.  With the new grounded system I experience fewer outages and only when the whole neighborhood has the same.  Happy guy.

 

And what happens in the event of an accidental L-N reversal or the neutral going open between the outlet and the board? Hint your computer will kill you!

 

You have created a TNC-S system within the installation, this is prohibited by pretty well every set of regulations that I am aware of (certainly UK and Aussie probably US [NEC] too).

 

Since you have a Safe-T-Cut type device try creating a L-E leak, just connect a 15W lamp L-E in one of your outlets. A correctly grounded system will trip the Safe-T-Cut.

 

The 3-lamp testers are not infallible, but it is entirely up to you what you believe ...

 

 

[MaiChai]

My first career was electronics and electrics so would consider myself knowledgeable and did my own electrics in my Thai house because most Thais havnt a clue.

 

If you look at UK consumer units, they typically have 2 rcb circuits; one for upstairs and one for downstairs. These are ultra safe, to the point where traditional light bulbs blow and trip them; this is a pain and requires a visit to the breaker box to reset them, BUT they are ultra safe and save lives!

 

With modern electrics, most things only have two wires, no earth, and have a plastic case; even washing machines. So the need for earth is much reduced. Some PCs have low quality power supplies and thats where you get the tingle off the usb. You could plug the pc into the mains the other way round to see if the tingle goes away? Personally i would use a laptop. 

 

Most Thai homes have no earth. With most electrical items having only 2 wires and double insulated via a plastic case; then there isnt much need for an earth? Unless you have an electric shower in which case you must have an earth. Some of the cheap showers dont even have a proper rcb; i would stay clear of these because i would not put my trust in penny pinching via the manufacturer! If you have one of these i would get it changed!

 

As a safety thing i turn the shower off at the breaker board; if it only gets turned on in the winter when it gets chilly and you need a warm shower. Mostly you want a cool shower.

 

I have seen some dodgy Thai electrics! For example live should be switched; but often the Thai electrician puts the switch on the neutral and thus does not understand electrics? The amount of times i have corrected this!

[Trumpish]

16 minutes ago, MaiChai said:

My first career was electronics and electrics so would consider myself knowledgeable and did my own electrics in my Thai house because most Thais havnt a clue.

 

If you look at UK consumer units, they typically have 2 rcb circuits; one for upstairs and one for downstairs. These are ultra safe, to the point where traditional light bulbs blow and trip them; this is a pain and requires a visit to the breaker box to reset them, BUT they are ultra safe and save lives!

 

With modern electrics, most things only have two wires, no earth, and have a plastic case; even washing machines. So the need for earth is much reduced. Some PCs have low quality power supplies and thats where you get the tingle off the usb. You could plug the pc into the mains the other way round to see if the tingle goes away? Personally i would use a laptop. 

 

Most Thai homes have no earth. With most electrical items having only 2 wires and double insulated via a plastic case; then there isnt much need for an earth? Unless you have an electric shower in which case you must have an earth. Some of the cheap showers dont even have a proper rcb; i would stay clear of these because i would not put my trust in penny pinching via the manufacturer! If you have one of these i would get it changed!

 

As a safety thing i turn the shower off at the breaker board; if it only gets turned on in the winter when it gets chilly and you need a warm shower. Mostly you want a cool shower.

 

I have seen some dodgy Thai electrics! For example live should be switched; but often the Thai electrician puts the switch on the neutral and thus does not understand electrics? The amount of times i have corrected this!

""With modern electrics, most things only have two wires, no earth, and have a plastic case; even washing machines. So the need for earth is much reduced. Some PCs have low quality power supplies and thats where you get the tingle off the usb. You could plug the pc into the mains the other way round to see if the tingle goes away? Personally i would use a laptop. ""

 

Can't abide laptops, if God meant us to use laptops he'd have given us 3 legs for better stability.

 

Could the USB tingles really be the PSU? It was bloody expensive... what else might it be?

[MaiChai]

Here is an interesting link: https://superuser.com/questions/461898/earthing-is-it-important-for-laptops

 

It would seem alot of laptops need earthing, especially if you connect it to something earthed as your floating 80 volts or so might cause problems. Surprised all these laptop manufacturers get away with this.  I checked my laptop psu and it has about 1k ohm between the earth pin and the negative on the laptop side.

 

But hey this is Thailand; dont expect perfection and you won't be disappointed! That tingle off the laptop can't be worse than an ant bite!

[RichCor]

1 hour ago, Trumpish said:

Could the USB tingles really be the PSU? It was bloody expensive... what else might it be?

The forums get this question constantly.

 

Wikipedia: Switched-Mode Power Supplies -- commonly used to power computers and electronic devices.

 

Due to regulations concerning EMI/RFI radiation, many SMPS contain EMI/RFI filtering at the input stage before the bridge rectifier consisting of capacitors and inductors. Two capacitors are connected in series with the Live and Neutral rails with the Earth connection in between the two capacitors. This forms a capacitive divider that energizes the common rail at half mains voltage. Its high impedance current source can provide a tingling or a 'bite' to the operator or can be exploited to light an Earth Fault LED. However, this current may cause nuisance tripping on the most sensitive residual-current devices.

 

So if your AC-powered electronic device doesn't have an actual  Earth-Ground connection the low-end energy normally bleed off harmlessly to ground by the EMI/RFI filter circuit then just sits there floating on the metal bits and pieces of the device chassis.

 

Short Answer:

Using a grounded plug point socket, or converting a two-pin to three-pin and running the third wire back to the CU (or a Earth-Ground) usually solves the annoyance.

 

 

[carlyai]

"He grounded the neutral bus bar in the box with a stake, installed three plug outlets to the two wire cable and bridged the ground screw to the neutral on each three way receptacle with a short wire."

If he was a real trained electrician, surely the Thai electrician must have been taught this at trade school.
You couldn't think this method of connecting grounds up on your own.

Sent from my SM-J700F using Tapatalk

[melvinmelvin]

Like was said above; today most appliances are 2-pin.

Thats also the case in my non-grounded house. I have heaps of power tools, including fairly heavy duty ones, 2-pin.

I am very comfortable with the house not being grounded.

 

Earthed houses are OK as long as the grounding is supplied by the power company.

Local grounding through metal rods and cables has some potential dangers.

 

Earth problems travel through the ground over short distances.

Meaning;

if your house, with all your appliances, is OK,

you can still get electrical shocks in your house from earthing problems with faulty

equipment in your neighbour's house.

This is not an odd event but rather normal behaviour.

 

So, be very careful and pedantic when doing your circuit breaker stuff.

[Crossy]

I understand the sentiments about most modern appliances being 2-pin and double insulated (Class-2). Indeed we have many 2-pin outlets in our home which I installed.

 

The key word here is MOST, most is not ALL.

 

There are still many Class-1 appliances, these are usually the ones with metal casework. They MUST be grounded to be safe, there is no alternative.

 

Common Class-1 appliances would be:-

 

Water heaters

Air-conditioners

Washing machines (with metal casework, drums etc.)

Desktop PCs (how many of us are complaining about tingles from these?)

Many kitchen appliances (grills, microwaves and kettles etc.)

 

If you don't ground these units they can and will kill.

 

We hear too often of someone dying from water heaters and the like, even ATMs have killed. We don't want our members or their families to join these statistics.

 

By the way, this is NOT a 2-pin plug:-

 

 

If your appliance has one it still needs a ground.

 

OK rant over, it's entirely up to you if you take any notice.

 

 

[melvinmelvin]

Crossy,

 

when you say:  " water heaters and the like, even ATMs have killed "

 

do you mean cash dispensing machines?

and

and water heaters for boiling water for a cup of tea/coffee?

 

(agree with your list of items that would (in most cases) need groundin, (I have none of them - lucky me))

 

[melvinmelvin]

Don't know if the following applies to the OP but thought I should mention it.

 

If I should purchase a ground needing device, eg a lathe or similar, I would not consider grounding the whole

house through a metal rod in the ground.

I would make an arrangement and supply ground to that device specifically.

 

This can be done relatively simply and cheaply, especially if you have water near your house.

(I have a longtailboat with a steel longtail by the house)

There is always 230V in the boat for maintenance charging the batteries.

Which turns the boat into a combined 230V-AC/12V-DC system.

 

Around the world, in marinas and harbours, grounding problems are plentifull and quite serious. They lead to shocks in the 230V-AC systems and in the 12V-DC systems metal components can be eaten up surprisingly rapid (ie propellers, shafts and what have you).

 

In shops supplying marine equipment you will find ways and means of tackling this.

There are relatively low cost components available that will purify your ground connection (in my case, the longtail dipped into the canal) and ensure that your ground needing device

is supplied with clean ground.

 

 

 

 

[Trumpish]

1 hour ago, melvinmelvin said:

Don't know if the following applies to the OP but thought I should mention it.

 

If I should purchase a ground needing device, eg a lathe or similar, I would not consider grounding the whole

house through a metal rod in the ground.

I would make an arrangement and supply ground to that device specifically.

 

This can be done relatively simply and cheaply, especially if you have water near your house.

(I have a longtailboat with a steel longtail by the house)

There is always 230V in the boat for maintenance charging the batteries.

Which turns the boat into a combined 230V-AC/12V-DC system.

 

Around the world, in marinas and harbours, grounding problems are plentifull and quite serious. They lead to shocks in the 230V-AC systems and in the 12V-DC systems metal components can be eaten up surprisingly rapid (ie propellers, shafts and what have you).

 

In shops supplying marine equipment you will find ways and means of tackling this.

There are relatively low cost components available that will purify your ground connection (in my case, the longtail dipped into the canal) and ensure that your ground needing device

is supplied with clean ground.

 

 

 

 

 

Many thanks for this. As it happens, this is (sort of) what I've had to do since the house was renovated and the electrician just ran 2 wires down the wall channel. Later the upstairs flooring was replaced, together with the downstairs ceilings, so ripping it all out to upgrade the wiring is probably not my first choice.

 

So. Rooms that do not require earthing stay with their 2-pin sockets. Rooms that have equipment in them which do require earthing (big fridge, microwave, shower heater, computers and servers etc - washing machine is outside with it's own earth) have separate earth circuits terminating in an  earthing stake outside. Now that I have learned how to test an earthing circuit, and together with comments from Crossy and all the others (thanks guys), I am much more confident that although the solution may not be elegant, the house is (or very quickly will be) safe for humans and equipment. Just a very few more things to do, including the the earth circuits that represented the original question, but I have the wire and the stakes to fix that, then it's off to the patio and a cold beer.

 

I've learned a fair bit from this thread, it's been very useful.

 

 

[Trumpish]

12 hours ago, RichCor said:

The forums get this question constantly.

 

Wikipedia: Switched-Mode Power Supplies -- commonly used to power computers and electronic devices.

 

Due to regulations concerning EMI/RFI radiation, many SMPS contain EMI/RFI filtering at the input stage before the bridge rectifier consisting of capacitors and inductors. Two capacitors are connected in series with the Live and Neutral rails with the Earth connection in between the two capacitors. This forms a capacitive divider that energizes the common rail at half mains voltage. Its high impedance current source can provide a tingling or a 'bite' to the operator or can be exploited to light an Earth Fault LED. However, this current may cause nuisance tripping on the most sensitive residual-current devices.

 

So if your AC-powered electronic device doesn't have an actual  Earth-Ground connection the low-end energy normally bleed off harmlessly to ground by the EMI/RFI filter circuit then just sits there floating on the metal bits and pieces of the device chassis.

 

Short Answer:

Using a grounded plug point socket, or converting a two-pin to three-pin and running the third wire back to the CU (or a Earth-Ground) usually solves the annoyance.

 

 

That's very helpful and is pretty much how I got to where I am. I put in an earth stake for the computers, but didn't know how to test it and, as I now know, it was not good. Hence the original post looking for help. Even with that earth circuit, I was getting small bites from the USB housings. So. I reckon that to solve, I need to:

 

1. replace the original earth stake and wire so that is is effective.

2. add an earth wire to the chassis of all 2-pin devices (printers and external HDD mainly), using one of those orange plugs you san solder an earth line to, and plug them all into an earthed 3-pin power board rather than have each of them take up a 3-pin socket. Not much power required for each device so it should be OK. 

 

Might be overkill but I'm fed up with getting small bites and tingles from casings when I leave a printer turned on, and I've spent a lot on the equipment which I would rather not see fried. Didn't have this problem in AUS or UK, Thailand is such a joy sometimes....

 

 

[Crossy]

2 hours ago, melvinmelvin said:

Crossy,

 

when you say:  " water heaters and the like, even ATMs have killed "

 

do you mean cash dispensing machines?

and

and water heaters for boiling water for a cup of tea/coffee?

 

(agree with your list of items that would (in most cases) need groundin, (I have none of them - lucky me))

 

 

A young child was electrocuted by an ATM (yes a cash dispenser) last year, it should be in the News forum.

 

My water heater comment really referenced shower heaters but most kettles (for tea) are actually Class-1 due to having metal heating elements even if they are plastic bodied.

 

BTW how's the boat? You need to come up our way to shoot some video

 

[RichCor]

1 hour ago, Trumpish said:

I put in an earth stake for the computers, but didn't know how to test it and, as I now know, it was not good.

 

Just know that individually grounding to an Earth Ground Stake isn't the same as having a dedicated third wire running back to your CU / breaker box.  As @melvinmelvin alluded to, an isolated Earth Ground Stake can also pick up and carry neighboring current leaks straight back to your equipment and you.

 

The recommended method is to common all Earth Ground Stakes together -and- to the CU Ground Bus (where hopefully your system also has the Neutral tied to Earth Ground via a MEN implementation). Having *everything* Earth Ground related tied together keeps everything at the same voltage potential with no hazardous variations between Earth Ground systems.

 

Though, having that RCD in your CU will probably be the 'thing' that saves your bacon.     

[melvinmelvin]

39 minutes ago, Crossy said:

 

A young child was electrocuted by an ATM (yes a cash dispenser) last year, it should be in the News forum.

 

My water heater comment really referenced shower heaters but most kettles (for tea) are actually Class-1 due to having metal heating elements even if they are plastic bodied.

 

BTW how's the boat? You need to come up our way to shoot some video

 

 

I knew you could get heart attacks from ATMs, but mainly due to the bad exchange rates rather than electricity.

 

(just checked me kettle, u caught me red handed, it has one of those plugs for screw in earth pin,

 my kettle (real 2-pin - bought in Europe) broke down - the lass bought a new one I never checked before now

 trip to Home Pro for finding a real 2-pin one is on the list)

 

Boat is ready and OK and nice. But since putting the engine back, in the new boat, end of september last year I have

experienced so many problems (some very time consuming to sort) that less than half of the problems would be more than enough.

Right now I am awaiting some spare parts from Brexit land. Need to change all the valve stem seals. Toyota Thailand

has only 6 seals and I need 32 (one for each valve) and shopping crucial oil seals from scrapyards is not to my

liking.

 

Yes, Bang Sai and your place is for sure on the list as soon as I have the mill running smoth as silk.

 

Now, since I started working 0530 today I think I'll join the OP with having a beer in the sala.

 

Now, hows that for off-topic, I better go and have that beer now.

 

 

[Crossy]

24 minutes ago, melvinmelvin said:

Now, hows that for off-topic, I better go and have that beer now.

 

Beer is NEVER off-topic, stuck at the office until about 3.30, beer at 4.30

[melvinmelvin]

MY SHORE POWER PANEL, OFFERING CLEAN EARTH (NON GROUNDED HOUSE):

 

 

Thought I would share this in case somebody here has an idea re supplying ground to a device or two in a non-grounded house.

 

The setup below is meant to supply clean grounded 230V to a pleasure craft in a marina/harbour with dirty power supply (which there are many of around the world).

Of course it would work equally well supplying the same to a device or two in a non grounded house.

 

Normally you would find the setup below mounted in the boat itself. The main “thingies” in the setup is the big white box (grounded 230V power central with two grounded outlet sockets, fuses, overload (amp and volt) protection, main switches, control lamp and circuit breaker) and the small black box which is a galvanic isolator.

I have opted to mount the stuff on a piece of plywood. Because I just cannot find a power central with IP67 properties and I am reluctant to drag stuff on board that has less than IP67 protection. Galvanic isolators with IP67 protection are easy to find but expensive.

 

So when needed, not often, I put the plywood sheet on board and connect to the house via a long shore power cable (2 strand) or alternatively I leave the plywood sheet in the sala and connect it to the boat via a long shore power cable (3 strand).

 

These two main boxes can be considered marine fare and can be found in marine/yacht supply shops. Not expensive stuff. The power central is produced in and bought in Norway – costing about 4000 baht (that includes 25% VAT), the other box is made in the UK, I think, and costs about the same.

 

 

 (not sure what is happening here, the above pic should be rotated 90 degrees to the left,

  the white socket list is horizontal)

 

A bit patchy but it works.

 

The upper white list with grounded sockets is connected to the house power supply, ie non grounded.

The grey area to the right on the white socket list is a measuring device that displays amperage, voltage, frequency and kWh for the 4 grounded sockets to the left of the display.

Below the socket list is an ordinary 20A fused on/off switch, (2 poled).

The lower left box is the actual power central.

The white box to the right of the power central is an ordinary grounded socket (Home Pro fare).

The black box to the right in the photo is the galvanic isolator for grounded connections.

The green cables are the ground connections.

The white lower right socket is for receiving ground from the boat, i.e. not from a battery or similar but from a dipped longtail or from the engine with parts dipped in the water eg drive shaft or similar.

 

«Ground» from shore is extracted from the plug in the upper left hand corner.

 

(Ie, my setup will work if I take it with me and connect to a grounded house.)

Red/black cable is phase and neutral and enters the 20A switch without ground,

Ground from the socket list (ie house) is led to the right hand terminal on the isolator.

Ground from the left hand terminal on the isolator is led into the 20A switch above the power central, hence, the power central is fed with phase, neutral and ground, which is further led to the boat.

Note; the white socket (lower right) is only for receiving ground from the boat and feeding it into the isolator, the socket is just a terminal. Ground from the white socket is led to the same terminal on the isolator from which ground for the power central is taken.

 

With this you should have a 230V supply with non-dirty earth for the price of say less than 12 cases of beer.

 

mai paeng

 

 

 

clean-earth.docx

[melvinmelvin]

now, where to find the boxes if interested

 

internet is an option of course, the big box would probably be called something along the lines of

Shore Power Central or Shore Power Control

 

several marine supply shops in Phuket should have this kind of stuff'

Bangkok does not have any useful marine supply shop

There is a shop named Lalizas in amp. muang Samuth Prakarn that might have this

 

In  NaJomtien/Sattahiip there is a place called Ocean Marina (this is just next door to Jomtien/Pattaya), there

are some very well stocked marine supply shops there,

one shop is called ASAP Marine the other is called Buzzcats Electrical.

 

 

[aussie11950]

Like was said above; today most appliances are 2-pin.
Thats also the case in my non-grounded house. I have heaps of power tools, including fairly heavy duty ones, 2-pin.
I am very comfortable with the house not being grounded.
 
Earthed houses are OK as long as the grounding is supplied by the power company.
Local grounding through metal rods and cables has some potential dangers.
 
Earth problems travel through the ground over short distances.
Meaning;
if your house, with all your appliances, is OK,
you can still get electrical shocks in your house from earthing problems with faulty
equipment in your neighbour's house.
This is not an odd event but rather normal behaviour.
 
So, be very careful and pedantic when doing your circuit breaker stuff.

You are very wrong.
A nearby earth problem in a neighbours house will not affect you.
The earthing is supplied by the house installation.
The power line does have an earth wire but it is earthed at your house and all other houses to earth a lightning strike.



Sent from my iPhone using Thailand Forum - Thaivisa mobile app

[Crossy]

Thailand is mostly TN-C-S with MEN, this is the same as the system in Australia.

 

Even if you have a 2-pin home the neutral will be grounded, possibly only at the transformer, but it will should be at or near earth potential.

 

In Thailand's case the N-PE (Protective Earth) connection is made inside the distribution board.

 

Look here for more detail https://en.wikipedia.org/wiki/Earthing_system

 

[melvinmelvin]

4 hours ago, aussie11950 said:

You are very wrong.
A nearby earth problem in a neighbours house will not affect you.
The earthing is supplied by the house installation.
The power line does have an earth wire but it is earthed at your house and all other houses to earth a lightning strike.



Sent from my iPhone using Thailand Forum - Thaivisa mobile app

 

Well, what kind I say. Guess I join Burger King and say "Have it your way".

 

The house I stay in and the house to the left of me and the house to the right of me have no earth.

No earth by the main switches/fuses. No earth supplied with the main supply cable, No earth in/by/of the pole

that supplies me and a few houses around.

 

May be some earthing close to the transformer, dunno.

 

Regarding earth problems at the neighbours popping up in my house:

I have years of personal and practical experience with this happening.

Not from Thailand. But in a 230V power distribution system with local grounding.

In a time when most piping was done with cast iron pipes rather than "plastic", which means ample

conductivity to bath rooms and kitchens.

 

 

[Trumpish]

An update for anyone so inclined...

 

I sorted the computer room earthing out today. I discovered the problem. Apparently, last year, when we had someone in to do some painting. He removed the outer plate of the plugpoint, and while he was at it, he removed the earth wire and just left in waving in the wind. And while the was at it, he put the second plugpoint assembly back in upside-down. Tosser. Painting done, plate back on, Bob's your uncle, all set.

 

No wonder I didn't have any earth line to the earth stake outside? New earth cable in plug-point, attach to existing stake, Test. All good. Perfect readings and connectivity all round. Job done. And while I was at it I tested the RCD on the circuit-breaker panel upstairs. All good.

 

But the air in our house today was considerably blue.

 

I am sincerely thankful for all the help I had. Thanks all. I know more about it now.

 

[lokocama]

Quote

The forums get this question constantly.

 

Wikipedia: Switched-Mode Power Supplies -- commonly used to power computers and electronic devices.

 

Due to regulations concerning EMI/RFI radiation, many SMPS contain EMI/RFI filtering at the input stage before the bridge rectifier consisting of capacitors and inductors. Two capacitors are connected in series with the Live and Neutral rails with the Earth connection in between the two capacitors. This forms a capacitive divider that energizes the common rail at half mains voltage. Its high impedance current source can provide a tingling or a 'bite' to the operator or can be exploited to light an Earth Fault LED. However, this current may cause nuisance tripping on the most sensitive residual-current devices.

 

 

Thank you for all the information, I know more now