Adding an earth to a 15th floor 20 year old condo.

[xylophone]

9 minutes ago, sometimewoodworker said:

Having built here and having looked in on numerous building sites you are wrong the buildings here, as far as rebar and concrete work is concerned  is reasonable. Also that the concrete IS part of the earthing.

 

That misunderstanding demonstrates your total lack of comprehension of the Ufer grounding system. This is common with many British sparkies who will not take the time to understand a different system.

 

I doubt that your suspicion has any grounding in fact.

Well I have also been on quite a few building sites here and have seen some very, very poor practices, so I wouldn't trust them as far as I could throw them.

 

And you might wish to avail yourself of some more information regarding the Ufer system, as follows: –At a recent seminar, one of the attendees asked, “What is a ‘Ufer’ ground?” This is a common question. A “Ufer” ground is slang for what the National Electrical Code (NEC) addresses as a concrete-encased grounding electrode.

Section 250.52(A)(3) clearly specifies what constitutes a concrete-encased electrode. The concrete-encased electrode can be bare, zinc-galvanized, or other steel reinforcing bars or rods of not less than ½ inch in diameter coated in electrically conductive material.

Sure it is a good system if it is installed like it should be, but then again this is Thailand.

 

And my total "lack of comprehension" saw me in good stead working in power generation, overhead lines, oil wells, offshore platforms and domestic installations in many countries, so I'm okay with my "comprehension" thank you.
 

[tifino]

• but always be wary of 

 

[jomtienisgood]

47 minutes ago, OneMoreFarang said:

How to do such test?

I work with electronics and I have a multimeter and other tools. But I have no idea how to check for good earth (on rebar).

Try the Covid PCR test.

[MayPutThai]

50 minutes ago, OneMoreFarang said:

How to do such test?

I work with electronics and I have a multimeter and other tools. But I have no idea how to check for good earth (on rebar).

First of all, I hope that all these hobby electrician never installed in that way what is supposed here.

You need to know that your earth/ground is build always in the house from the neutral. The main grid from outside have 4 cable.

3 phases with the power and one neutral for all.

If the load on all three phases is the same then through the neutral will no current flow. 

What to do is, you can connect the neutral to another bar in your breaker casing. From here the two lines go separate the ground (green or green/yellow is further your ground in your room)

the original neutral has to go together with the phase through a residual current circuit breaker and from behind this you connect the breaker and the neutral bar as it is actually.

https://en.wikipedia.org/wiki/Residual-current_device

If you can find any other ground then you must connect this to the neutral/ground before the RCCB.

Steel water pipe, as many times mentioned here, have no guaranteed ground to the soil and water is no conductor. Only Salt water can be used as a bad conductor. The fire water pipe have, but is absolutely forbidden to connect any to this on good reason.

You can go and use the steel construction at stair case etc and ground this at ground floor with a rod in the soil. Not only in the concrete. It must end some meter in soil.

At your shower heater you should have this usually also installed.

You can find this at the heater if there is a test and reset button somewhere. 

I have seen very often that Thai electrician just put a rod into the soil and connect only the ground here without making the bridge to the neutral. That does not help. You can have then even a static voltage between neutral and ground. But with the bridge you have at least both at the same level.

[MayPutThai]

2 hours ago, paulbrow said:

For what it's worth, the water itself is a fine conductor, pretty much nullifying the plastic pipe, hence the need for a solid ground.

NO, Only Salt Water is an even bad conductor! 

Normal Water has too less minerals to be a salty water.

Never use waterpipe as ground. There is no guarantee.

The water from the water plant is delivered through PVC Pipe too and you don't know where the steel have contact to wet soil.

Even you don't want the steel starting rusting.

[sometimewoodworker]

16 minutes ago, MayPutThai said:

 

I have seen very often that Thai electrician just put a rod into the soil and connect only the ground here without making the bridge to the neutral. That does not help. You can have then even a static voltage between neutral and ground. But with the bridge you have at least both at the same level.

That is bad advice.
 

If you should bridge neutral and earth depends on your supply. Thailand is moving to a TNCS with MEN but not all supplies have been switched so doing that can be a very bad idea. The simple way you can tell is if every third, or so, power pole is earthed. The age of the building gives no information.

 

For a TT supply a good earth rod is correct, with or without a Ufer ground.

[KhaoYai]

On 1/15/2021 at 6:13 AM, Crossy said:

Yeah, that's a shame, I've seen units that take an earth to the board then no further.

I know the OP mentions its a 20 year old condo but that's not exactly the stone age - doesn't sound old at all when you say the year 2000.  Was it legal to not provide an earth at that time?

 

I've seen plenty like this and some where individual circuit earths are connected to the bar but go no further in provincial houses but I would have expected greater compliance in a city condo.

[KhaoYai]

35 minutes ago, MayPutThai said:

If the load on all three phases is the same then through the neutral will no current flow. 

Is your real name Yoda?

 

Sorry, couldn't resist that.

[sometimewoodworker]

1 minute ago, KhaoYai said:

I know the OP mentions its a 20 year old condo but that's not exactly the stone age - doesn't sound old at all when you say the year 2000.  Was it legal to not provide an earth at that time?

You must be new to Thailand if you think that wiring regulations have much meaning. The PEA will often not actually do an inspection, they did not with my house, that is wired correctly,

[sometimewoodworker]

1 minute ago, KhaoYai said:

Is your real name Yoda?

 

Sorry, couldn't resist that.

Probably google translation

[OneMoreFarang]

18 minutes ago, KhaoYai said:

I know the OP mentions its a 20 year old condo but that's not exactly the stone age - doesn't sound old at all when you say the year 2000.  Was it legal to not provide an earth at that time?

Maybe in 2010 I was in the electrical control room from a big "modern" just built shopping center in Bangkok. What I saw was shocking. Lots of main voltage wires hanging over a sharp edge of a steel conduct into the room. There were at least 10 engineers working there and it seems nobody noticed and nobody cared. Amazing Thailand.

[Crossy]

Attention Everyone!

Before making statements such as "you must do XXX" please remember that different parts of the world have differing regulations.

 

The best match for Thailand is probably AS3000 but even that has some significant differences to the Thai regulations.

 

I see we have posts from the UK, various European countries, Oz etc. etc. what your regs say may not agree with what the Thai regs say.

 

Thailand is (mostly) 3-phase, four-wire with 220V phase-neutral  (230V in greater Bangkok), allowable earthing systems being TT, TN-S and TNC-S with MEN the latter being what the latest regulations aspire to (but not necessarily implemented in your area).

 

So if you are going to state "you must", you must also quote the relevant Thai regulation.

 

[xylophone]

52 minutes ago, MayPutThai said:

First of all, I hope that all these hobby electrician never installed in that way what is supposed here.

You need to know that your earth/ground is build always in the house from the neutral. The main grid from outside have 4 cable.

3 phases with the power and one neutral for all.

If the load on all three phases is the same then through the neutral will no current flow. 

What to do is, you can connect the neutral to another bar in your breaker casing. From here the two lines go separate the ground (green or green/yellow is further your ground in your room)

the original neutral has to go together with the phase through a residual current circuit breaker and from behind this you connect the breaker and the neutral bar as it is actually.

https://en.wikipedia.org/wiki/Residual-current_device

If you can find any other ground then you must connect this to the neutral/ground before the RCCB.

Steel water pipe, as many times mentioned here, have no guaranteed ground to the soil and water is no conductor. Only Salt water can be used as a bad conductor. The fire water pipe have, but is absolutely forbidden to connect any to this on good reason.

You can go and use the steel construction at stair case etc and ground this at ground floor with a rod in the soil. Not only in the concrete. It must end some meter in soil.

At your shower heater you should have this usually also installed.

You can find this at the heater if there is a test and reset button somewhere. 

I have seen very often that Thai electrician just put a rod into the soil and connect only the ground here without making the bridge to the neutral. That does not help. You can have then even a static voltage between neutral and ground. But with the bridge you have at least both at the same level.

The problem I have encountered here is that houses are wired in any way whatsoever that the person who wires them decides upon the day!

 

I have seen supposed earth wires taken back to the distribution board and cut off, connected to nothing. I have also seen installations with no earth wire whatsoever and those with no indication of a MEN connection.

 

I've also had an air conditioner fed directly off the power pole outside of the house, without going anywhere near a distribution board, and many more horror stories.

 

And the one to top it all is where the Thai "electrician" said that Thai electricity doesn't need an earth.

 

I have seen a couple of houses wired the old-fashioned TT way and at least there is an earth wire running throughout the house, back to the distribution board and then into the ground. 

 

I think each case could be different, as Thailand doesn't seem to have had the regulatory oversight that other countries have had, however I have seen a couple of houses here wired the old fashion TT way, so at least it's a start, or should I say it's an old-fashioned start!

[Crossy]

You can get the Thai regs here https://eitstandard.com/มาตรฐานการติดตั้งทางไฟ-2/#

 

At 225 Baht it's a bargain compared to our Western regs.

 

[KhaoYai]

48 minutes ago, sometimewoodworker said:

You must be new to Thailand if you think that wiring regulations have much meaning. The PEA will often not actually do an inspection, they did not with my house, that is wired correctly,

Not new to Thailand at all and I know very well what the general attitude to wiring is - that should be apparent from the examples I gave. I was simply asking if it was legal to fail to provide an earth. The reason being that if the regulations at the time did require an earth, the OP would surely have some recourse to the law and might get something done if he brought the matter to the attention of the building owner/management company.

[najomtiensun]

Thanks for all the 'meaty' replies - looks like I have opened a can of worms. The path of least resistance (geddit) is to do nothing and take the shower back to HomePro a solution which is under active consideration. I insisted on buying a relatively expensive Japanese model Rinnai at 6500 baht as I believe they will be built and tested to higher standards than Thai or Chinese models at half the price. If we get a recommended sparks in then my total budget for a verifiable solution will be 5k max. If more will be 'nam yen' for foreseeable... 

[lopburi3]

57 minutes ago, najomtiensun said:

I insisted on buying a relatively expensive Japanese model Rinnai at 6500 baht

Are you sure it is not made here at Rinnai Thailand?  Does the model number get Japanese or Thai hits on Google?  Many water heaters are of Japanese design but made here under a local model number.

 

Is this a multi-point heater?  In that case would not require being in bathroom and you would use a mixer tap?

[najomtiensun]

5 minutes ago, lopburi3 said:

Are you sure it is not made here at Rinnai Thailand?  Does the model number get Japanese or Thai hits on Google?  Many water heaters are of Japanese design but made here under a local model number.

Well spotted it is indeed made in Thailand !

[Crossy]

Since our OP has decided upon a plan of action I'm going to close this on for now.