Earthing an unearthed (old) condo

[TVBKK2020]

In an old condominium in Bangkok, each unit (address) has only 2-pin electrical sockets. 

The in-house engineers state that they can change these sockets to be 3-pin ones.

When asked, the engineers state that as part of the job, there will indeed be "wires" connected to the earth connectors of the new sockets.

 

How likely is it that on completion of the conversion from 2-pin to 3-pin sockets, which is for only one unit in the condo, that the unit in question will actually be properly earthed?

 

[bankruatsteve]

How likely is it?  If you can't answer, it's not likely anyone else can either.  The obvious way to check is to see if the ground/earth bar in the CU is bonded to earth via cable to a stake in the ground or, more likely, Ufer grounded to the structural steel.  Have the spark explain what he did.  Then the ground wires going to the sockets should also be connected to the same bar.  

[Crossy]

The single most difficult task is going to be getting that 3rd wire into the existing containment and back to the board. Getting an actual ground is likely to be peanuts in comparison.

 

Whatever you do don't let them connect the E to the N in the back of the outlet, no matter what they say it is not "the same". It's called TNC and there's a reason that it's not permitted within an installation by any set of regulations that I'm aware of. If it's part of the supply network it's a different animal.

 

[millymoopoo]

23 hours ago, TVBKK2020 said:

How likely is it that on completion of the conversion from 2-pin to 3-pin sockets, which is for only one unit in the condo, that the unit in question will actually be properly earthed?

 In Thailand, with Thai electricians/handymen I would say 1% chance likely..!

Instruct them to install all earth wires to an earth spike next to a permanently wet area, like a well or soak and also install an ELCB (earth safety switch).
Then go check your switchboard to see the safety switch is indeed installed, then take a piece of wire bared at both ends, insert one end first into the earth pin position on the new socket and the other into one of the the two normal pin positions, switch the power point on, if nothing happens, switch off, insert wire into the other normal pin position, switch on, again if nothing happens there is no earth.
If there is an earth the aforementioned action will trigger the safety switch.

[The Theory]

On 10/12/2020 at 10:36 AM, TVBKK2020 said:

How likely is it that on completion of the conversion from 2-pin to 3-pin sockets, which is for only one unit in the condo, that the unit in question will actually be properly earthed?

My guess is:

There is no Ground wire, the 3rd pin is connected to "Neutral". 
 

[Harveyboy]

22 hours ago, Crossy said:

The single most difficult task is going to be getting that 3rd wire into the existing containment and back to the board. Getting an actual ground is likely to be peanuts in comparison.

 

Whatever you do don't let them connect the E to the N in the back of the outlet, no matter what they say it is not "the same". It's called TNC and there's a reason that it's not permitted within an installation by any set of regulations that I'm aware of. If it's part of the supply network it's a different animal.

 

had this prob at my no earth any where new 3 pin sockets but no earth wire  got a company in waste if money still hot shocked from most   appliances...Re wire to be safe ..just saying from experience

[ross163103]

Best to get a reputable western electrician if you can find one, even if you have to pay more for it. In my experience the Thai electricians just don't have the skills involved for this type work. I know there are some qualified Thais out there but very hard to find. There are too many "Pee Somchais" that will tell you they know what to do......but don't. With some construction jobs this wouldn't matter but with electricity it could cost you your life.

[xtrnuno41]

NON, ask them, you to show it is going to an ground bar connected with a ground rod.

You have something now with 3 pins? Thats why you changed to 3 pin socket?

Well your fridge should have also a 3 pin. Does it? You do have it? Then also you could have ground already.

Make it safer for your self and change your breakers in the box for RCBO's , just every group with their own RCBO or just

a general rcbo for all. 30mA differential  switching.

 

[TVBKK2020]

Thank you very much everybody here for your replies to my post.

I was planning on buying that condo but I just "pulled the plug" on it.

The wiring/earth issue was just one of many which compounded to result in a no-deal.

 

[impulse]

Asking the sparkies, because I'm not up on Thai/220V home wiring codes...

 

Is this a good thing to have in Thailand, or a waste of time and money?

 

https://www.amazon.com/Advanced-Automatic-Electric-Polarity-Detector/dp/B07L4QVFQQ

[Crossy]

12 hours ago, impulse said:

Asking the sparkies, because I'm not up on Thai/220V home wiring codes...

Is this a good thing to have in Thailand, or a waste of time and money?

https://www.amazon.com/Advanced-Automatic-Electric-Polarity-Detector/dp/B07L4QVFQQ

 

Not that one, it's intended for US use, you need a 220V unit with a 30mA earth leakage test. Lazada has them.

 

There's a thread somewhere with links to suitable Lazada units.

 

EDIT These look suitable https://www.lazada.co.th/products/habotest-ht106t-socket-tester-i316566794-s634644284.html