How Can I Find Out How My Property Is Earthed?

[naughtybadfurrimunki]

Hi guys,

I need to find out how my house is earthed. I need to find where the earth rod is and find out its impedance.

Nearly every time my wife or I touch the washing machine we get a minor electric shock. Additionally, I have a lot of very expensive audio equipment and am planning to set up a recording studio in one of the spare bedrooms, but there's no way I'm going to do this unless the property has a MEN earthing system to protect my gear.

If I find the property is not earthed by a MEN system can it be upgraded? If so, does anyone know what kind of money I'd be looking at to get it done? Would it be a huge job? Could a Thai electrician be trusted to do such a job? Would a Thai electrician even know what a MEN earthing system is?

BTW...The plug sockets in the house are all 3 pin. I guess I should unscrew one and see if the earth is actually connected but how do I find out if it's connected at the other end? Also, where do I go from there? I have no electrical knowledge except I know how to wire a UK plug! I'm just a music / hi-fi guy who wants to give as much protection as possible to expensive equipment and household appliances.

Sorry if this has already been covered, I'm busily working my way through all the related threads and have been reading Crossy's excellent guide but as yet I haven't found the info I'm looking for.

I guess the bottom line is this: If my house isn't earthed using a MEN system and can't be upgraded to one I'll be moving out asap!

Many thanks for any input. Any guidance is, as always, greatly appreciated.

[Crossy]

A few quick thoughts.

Yes, pop the outlets off (power off) and check if there is a green wire going somewhere.

Inside the distribution board you should find a bar with all the green wires plus another going to your ground stake.

There may be a link between ground and neutral (MEN link).

To do anything more you'll need at least some test gear (a multimeter) and some idea how to use it.

What sort of plug is on the washing machine? Getting tickles certainly suggests that it's not grounded, but if it's got a Schuko plug and that's inserted without an adaptor then there's no surprises.

If you wish post clear photos of the distribution board with the lid off so others can interpret what you've got

Even if grounding and MEN isn't implemented, it's not a huge job to sort things out but it would have been nice if it was done from new.

[aussiebebe]

You can use the Thailand Yellow pages to source an electrician who will have to visit your property to inspect and advise. I wouldn't advise you to unscrew any electrical sockets to 'check' and the 'shocks' from the washing machine is impossible to speculate; faulty appliances?

[Aromaz]

It is almost guaranteed that your house is NOT earthed at all.

Most likely you will not even find an earth wire in the wiring system.

Sometimes (seldom) it is there but only leads to main board; no earthing.

The fact that you do get shocks - more obvious your house is not earthed.

You can get electrician to do it; or you can do it yourself.

Presently staying in my 6th house in Thailand - this one I build. Previous five - no earthing.

[bankruatsteve]

Well, as Crossy explained, the earthing check is fairly simple. But, whether it has/has not probably doesn't matter. Why? B/C in Thailand almost NOTHING in terms of local produced appliances or other electrical equipment comes with 3-prong plug. And, if it does, there's a good chance nothing is even connected to the ground plug. (like most extension blocks sold here). Most refrigerators, washing machines, water systems, etc. come with their own little green wire that you're supposed to hook up to a ground. So, if you do have proper gounding, you could hook that into the outllet connecting to the ground in that. Otherwise, you need to choose one of the methods discussed in this forum to ad nausiam.

[wpcoe]

Yes, pop the outlets off (power off) and check if there is a green wire going somewhere.

Inside the distribution board you should find a bar with all the green wires plus another going to your ground stake.

Don't be shocked (pun intended) if the ground wire isn't green. The three ground wires in my rented townhouse (one each for two shower water heaters, and one on the water pump) are all have white sheathing. Standards would be nice, but this is Thailand, after all.

[naughtybadfurrimunki]

A few quick thoughts.

Yes, pop the outlets off (power off) and check if there is a green wire going somewhere.

Inside the distribution board you should find a bar with all the green wires plus another going to your ground stake.

There may be a link between ground and neutral (MEN link).

To do anything more you'll need at least some test gear (a multimeter) and some idea how to use it.

What sort of plug is on the washing machine? Getting tickles certainly suggests that it's not grounded, but if it's got a Schuko plug and that's inserted without an adaptor then there's no surprises.

If you wish post clear photos of the distribution board with the lid off so others can interpret what you've got

Even if grounding and MEN isn't implemented, it's not a huge job to sort things out but it would have been nice if it was done from new.

thanks for the input Crossy, will post photo over the weekend

[electau]

First you should consider obtaining the services of an competent electrical contractor.

They will or should carry out tests on the earthing system

1. Visual check of main earth and connections.

2. Visual check MEN or TT at main neutral link.

3. Main Earth continuity check using a continuity tester. ( max 0.5ohms)

4. Continuity check of all final sub circuit PE conductors

5. Check earth bonding ( continuous metallic water piping that enters the ground).

Other tests.

1. Insulation tests

2. Correct connection tests

3 Polarity tests.

4. Verification of impedance (earth fault loop impedance) on socket outlets not protected by an RCD (MEN system only) This can be carried out using an ohmmeter or by a suitable instrument designed to measure low impedance values.

5. Operation of all RCDs (time/current--ms/30mA.) This test is done last of all.

The max resistance from any part of the earthing system to the main earth connection in practice should not exceed 1.0 ohm.

(Based on the requirements of AS3000).

Edited April 22, 2011 by electau

[PlastikbinLina]

Providing a satisfactory ground requires someone with the proper training and equipment. Having a rod stuck into the soil outside (or inside) your home doesn't mean you have an effective Earth. For example if the surrounding soil is sand it will be completely useless. If it is a floculent soil e.g. a clay type, its resistivity will change with the seasons. Wet= excellent Dry= poor. The soil resistivity needs first to be tested with a galvanometer connected to three rods, spaced apart according to the depth the tester wishes to check the soil resistance. The resistance tested could indicate that you need more than one rod attached to each other either vertically or horizontal. Horizontal in the ground where rocky soils are found. With regard to earthing standards this country is not Robinson Crusoe. Even in Western countries most electricians have little or no knowledge of proper Earthing methods. Many tradesman just piss on the earth surrounding the ER before leaving the scene hoping things will work out. But in the field of telecommunications and power where proper earthing is critical then you can guarantee the soil resistivity is tested and appropriate action taken to design and maintain the wanted (constant) resistance. Home earthing resistance is usually acceptable at 10 ohms or less.

Edited April 22, 2011 by seht1912

[electau]

Providing a satisfactory ground requires someone with the proper training and equipment. Having a rod stuck into the soil outside (or inside) your home doesn't mean you have an effective Earth. For example if the surrounding soil is sand it will be completely useless. If it is a floculent soil e.g. a clay type, its resistivity will change with the seasons. Wet= excellent Dry= poor. The soil resistivity needs first to be tested with a galvanometer connected to three rods, spaced apart according to the depth the tester wishes to check the soil resistance. The resistance tested could indicate that you need more than one rod attached to each other either vertically or horizontal. Horizontal in the ground where rocky soils are found. With regard to earthing standards this country is not Robinson Crusoe. Even in Western countries most electricians have little or no knowledge of proper Earthing methods. Many tradesman just piss on the earth surrounding the ER before leaving the scene hoping things will work out. But in the field of telecommunications and power where proper earthing is critical then you can guarantee the soil resistivity is tested and appropriate action taken to design and maintain the wanted (constant) resistance. Home earthing resistance is usually acceptable at 10 ohms or less.

A satisfactory earthing system is one that complies with a recognised standard. Example. AS/NZ,BS or IEC.

The minimum is regarded as a 12.7mm copperclad steel electrode driven at least 1.2 metres along with a ME conductor 4sqmm minimum, including earth bonding and PE conductors.

For example. Under AS3000 the resistance of the electrode to the surrounding soil is not required to be tested as the area in contact with the soil is regarded as sufficient and MEN system is mandatory. (However if the TT system is used earth resistance measurements may be required. A typical value for a single electrode is in the order of 70 to 100 ohms). With a TT system RCDs must be used for earth fault protection.

To state that electricians in Western countries do not understand earthing is not true. It is you that does not understand the training and licencing, mandatory testing and the legal obligation requirements for electricians.

　

[PlastikbinLina]

Providing a satisfactory ground requires someone with the proper training and equipment. Having a rod stuck into the soil outside (or inside) your home doesn't mean you have an effective Earth. For example if the surrounding soil is sand it will be completely useless. If it is a floculent soil e.g. a clay type, its resistivity will change with the seasons. Wet= excellent Dry= poor. The soil resistivity needs first to be tested with a galvanometer connected to three rods, spaced apart according to the depth the tester wishes to check the soil resistance. The resistance tested could indicate that you need more than one rod attached to each other either vertically or horizontal. Horizontal in the ground where rocky soils are found. With regard to earthing standards this country is not Robinson Crusoe. Even in Western countries most electricians have little or no knowledge of proper Earthing methods. Many tradesman just piss on the earth surrounding the ER before leaving the scene hoping things will work out. But in the field of telecommunications and power where proper earthing is critical then you can guarantee the soil resistivity is tested and appropriate action taken to design and maintain the wanted (constant) resistance. Home earthing resistance is usually acceptable at 10 ohms or less.

A satisfactory earthing system is one that complies with a recognised standard. Example. AS/NZ,BS or IEC.

The minimum is regarded as a 12.7mm copperclad steel electrode driven at least 1.2 metres along with a ME conductor 4sqmm minimum, including earth bonding and PE conductors.

For example. Under AS3000 the resistance of the electrode to the surrounding soil is not required to be tested as the area in contact with the soil is regarded as sufficient and MEN system is mandatory. (However if the TT system is used earth resistance measurements may be required. A typical value for a single electrode is in the order of 70 to 100 ohms). With a TT system RCDs must be used for earth fault protection.

To state that electricians in Western countries do not understand earthing is not true. It is you that does not understand the training and licencing, mandatory testing and the legal obligation requirements for electricians.

　

[PlastikbinLina]

I gave a simple answer to a simple request and for general knowledge only. I am sure your reply quoting different standards would not help anyone without experience in this field who wants to get power protection. In summary. It sounds as though you are an offended electrician because of my remarks about competancy in Western countries. I have over 50 years in this field and I'm not about to spar with you on technical matters. Go and have a cold beer and get over it.

[Aromaz]

When one comes to Thailand he/she should leave their home at home; do not expect Thailand to be the same as your home. Asia is Asia - it is a wonderful part of the world and wonderful people. It is NOT the same as your home country. If you do not like things here - the go back to where you came from. I am sure your standards there are high, qualified, excellent - and costly. There you call the electrician (and accept he is qualified else you have authorities to complain to) or the plumber and do accept his status means he has qualifications.

In Asia it does not work that way. Try to complain about an incompetent electrician or plumber .

If you want Thailand to be the same as your home country - better go back to your worderful home. What are you doing here?

Unfortunately the standards of education and Electricians in Thailand (Asia) most likely does not compare with that of your home country. Unfortunately it is also up to oneself to ensure your own living conditions and safety standards are of higher quality. Unfortunately if you rely on Local Electricians - you will find the lack of Earth wires, very silly and messy main board wiring and above all; absolutely no understanding of Earth Rods. Fortunately all soil in Pattaya region is clay like, usually damp to wet at less than 1 meter, thus no need to be very concerned about high educational testing. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office"

On the other hand; the earth is so 'dirty' with electrical currents from neighbours sometimes I wonder if and earth wire is really of safety value.

I found the very interesting issue when I helped various friends. Slamming (or mostly even hand push) a 2.5 meter earth rod into the soil and "Fluke" that to Neutral of main supply I get up to 94 VAC depending on location and time of day. About three years ago I even had 'Single Wire' 32W fluorescent tubes all my land - and posted Video to that effect on YouTube.

VIVA to those who discovered it is up to themselves to DIY their own lives in Asia including Thailand - and doing to efferts to learn how to do it before they foolishly start doing.

Edited April 22, 2011 by Aromaz

[naughtybadfurrimunki]

It seems the tone of this thread has taken a turn for the worst over the past couple of days. Oh well, not to worry... business as usual on Thaivisa. Thanks for all the responses anyway guys.

All info is useful and I'd appreciate a visit from any of you with such in-depth knowledge!

As originally suggested by Crossy, I've taken photos of the distribution board and had a poke around behind one of the wall sockets in the living room, hope the images help (I apologise for the shitty image quality), please see below.

I also had a look outside and as far as I can tell the washing machine, water pump and oven/hob are not earthed properly. The guy who came and did the outside wiring has utilised the neutral as the earth.

The washing machine is a top of the line Siemens (made in Germany not Thailand). It's fitted with a 3-pronged plug so one would assume it has an earth connector in the plug. The oven is also Siemens, however it has a green/yellow wire at the back that should be connected to an earth.

This is something I was sent regarding why I need an MEN system:

"If your intent is to ensure that you have clean electricity supplying your apparatus, ensure that your home earthing system is correct & that you also have an MEN link in your main distribution board. This link connects the main neutral to the main earth conductor. By doing so, you can greatly clean your power. In Thailand, this is not generally done which is very dangerous & also allows the neutral conductor to have a floating voltage present (usually associated with harmonics etc). This floating voltage can (and generally does) shorten the life of electronic equipment."

As I stated in my original post I have a lot of very high value studio equipment; protection is paramount to ensure its longivety. I'll also be employing power stabilizer(s) something like this to give added protection.

Thanks again for any further info, much appreciated.

Edited April 24, 2011 by naughtybadfurrimunki

[Crossy]

OK. The good news is that you seem to have a standard Thai implementation of MEN, feeding the neutral through the ground bar seems to be the way it's done here. Whilst electrically identical to providing an actual link between N and E it does make it difficult to perform installation tests that need the link removing, seems the Thai way is to perform the DIN standard 'bang' test

Hopefully the slightly thinner black wire on the ground bar goes off to your ground stake wherever it's located. If you can't find it and verify its integrity there is no reason whatever why you should not add a second stake where you can verify it's ok.

Those taped joints behind the outlet are also, sadly, Thai standard. I would get yourself some wire nuts and re-do all the ones you can get at.

[electau]

From your photographs of the main switchboard it would appear that the main neutral terminates on the earth bar instead of the main neutral link and the neutral then goes to the main switch (MCB).

The neutral link appears to be adjacent to the main switch.

There appears to be no main earth conductor (which should terminate at an earth electrode external to the building). It should be green or green /yellow, minimum 4sqmm.

You have a neutral - earth link but no main earth.(?) If you had an open circuit neutral your earthing system would rise to full line voltage. Earthing the neutral means to connect to an electrode. If you can not verify the main earth install a new one to an electrode.

The main earthing conductor runs from the main earth bar.

If you have sensitive electronic equipment it would be advisable to install a surge protection device.

The correct way to install an MEN is

1. Neutral to the main neutral link.

2. Main earth from the main earth bar to electrode.

3. MEN link from the neutral link to the earth bar.

The MEN link can then be removed for test purposes.

You should have an PE at every point of utilisation, eg socket outlets, aircon,etc and they should run back to the earth bar in the switchboard.

[Crossy]

Agree ^^^ Electau, except:-

I see a black wire that looks like it may be the main earth electrode just to the right of the neutral connections.

As I noted in my last post, what has been done is the normal Thai connection for MEN / TN-C-S it's how all the government house plans show being connected (no I don't like it either).

EDIT. Just to demonstrate, this is part of the wiring diagram from one of the government house plans.

[electau]

One would agree with you Crossy.

1. The black wire which you seem to think may be the main earth should be green or green /yellow as black is a phase colour.

2. The neutral should be clearly identified by white sleeving at each end.

From the PEA drawing the earths are connected to the main neutral link which makes polarity testing and all testing very difficult as the earths and neutrals must be electrically separated. A separate earth bar could easily be fitted.

What made me doubt than there was a main earth was the fact that a subcircuit neutral was found to be used as a protective earth, in other words the electrician may have understood that bonding only was required.

[Nawtier]

How many beers would it cost to get this info in English ??.....preferably Aussie english....and even better outback aussie lingo ??

We are getting shocks from severalmitems in the house currently....waiting on &lt;deleted&gt; owner to do something..

[powderpuff]

Where are you staying?

[Nawtier]

Where are you staying?

who me ??

[electau]

How many beers would it cost to get this info in English ??.....preferably Aussie english....and even better outback aussie lingo ??

We are getting shocks from severalmitems in the house currently....waiting on &lt;deleted&gt; owner to do something..

How severe are the electric shocks that you are receiving? From what you say it would appear that you have no earthing or poor earthing.

[Nawtier]

Not enough to throw you against the wall....have had that before.....just unpleasant low level electric fence type shocks.

Had them from computer, electric small oven, TV if you touch the rear where the screws are and the DVD thus far.

The SafetyCut is not working and waiting on owner to have it replaced....been promising to do it over last few weeks.....there is an issue of distance between him and us...but regardless.

[powderpuff]

Where are you staying?

who me ??

OP

[powderpuff]

How many beers would it cost to get this info in English ??.....preferably Aussie english....and even better outback aussie lingo ??

We are getting shocks from severalmitems in the house currently....waiting on &lt;deleted&gt; owner to do something..

Where do you live?

[electau]

Not enough to throw you against the wall....have had that before.....just unpleasant low level electric fence type shocks.

Had them from computer, electric small oven, TV if you touch the rear where the screws are and the DVD thus far.

The SafetyCut is not working and waiting on owner to have it replaced....been promising to do it over last few weeks.....there is an issue of distance between him and us...but regardless.

Your installation has poor earthing or no earthing also.Have you tested the RCD at the test button? this will test the operation of the device. If this does not work replace the unit.

Edited April 26, 2011 by electau

[Nawtier]

PP.......2 hours NE of BKK

Electi......how to fix to make safe and sure ?? ...rented house, not mine...

[kaorop]

I had to run a wire down the outside of my apartment 4 floors down! heavy gauge wire, stainless steel tube about 1/2 meter in wet soil wire hose clamped tight. did try it on some gal steel water pipe but it didnt work bit rough and ready but it was necessary and wasn't going to happen by the landlords. No shocks now

[electau]

PP.......2 hours NE of BKK

Electi......how to fix to make safe and sure ?? ...rented house, not mine...

If you have no earthing system or none of your electrical equipment is bonded to earth touch voltages like this will always be a problem. The voltages themselves are at safe levels, ie less than 50VAC. You need to get your earthing fixed first.

[bankruatsteve]

PP.......2 hours NE of BKK

Electi......how to fix to make safe and sure ?? ...rented house, not mine...

If you have no earthing system or none of your electrical equipment is bonded to earth touch voltages like this will always be a problem. The voltages themselves are at safe levels, ie less than 50VAC. You need to get your earthing fixed first.

Good advice as usual. BUT - if the appliance doesn't provide a grounding connection (and most of those the OP mentioned usually do not if from Thailand) then whether the earthing system is good or not really doesn't matter unless you manually ground everything. I have also found that giving those things a good vaccum can help to get rid of the shocks as dust and cobwebs can carry enough juice to feel it.