New House Wiring in Vietnam

[Mfatic]

Hello. First post, but for a friend who has tried to sign up but has been waiting for a week for a confirmatory email. We assume because he is signing up from abroad.

Anyway, to the question.

He is about to embark on building a new house in Vietnam, where he lives and works.
Currently, the plugs in Vietnam are just two pin, with no earth.
He wants to instruct the electrician to use three pin plugs and to wire in an earth.
He thinks he will struggle to obtain the plugs in Vietnam, bur he can source these from Europe.
The round pins also fit in the usual Vietnam plugs. They accept 2 pin flat or round pins.
He thinks he will also struggle to instruct the electrician with what he wants, but his wife is Vietnamese and is bi-lingual, so hopefully they can get around that problem.

My own education from over 50 years ago suggests that if the supply is not earthed at source, then a local earth can be dangerous.

From my own research, I think that the supply is earthed at source to the neutral, but I am not able to verify this.
As far as we can determine, no earth wire is supplied with the supply. (at all existing installations examined, no earth wire exists with the supply)

Is he being sensible in wiring in an earth to each plug, and should he connect this to an earth rod inserted in the ground?
Or is it possible to insist on an earth wire to be supplied with a new supply, (it is a new supply)?

Thanks for any help or suggestions.

 

[EFLImpudence]

Obviously I know nothing about Viet Nam's electrics.

He is about to embark on building a new house in Vietnam, where he lives and works.
Currently, the plugs in Vietnam are just two pin, with no earth.
He wants to instruct the electrician to use three pin plugs and to wire in an earth.
He thinks he will struggle to obtain the plugs in Vietnam, bur he can source these from Europe.
The round pins also fit in the usual Vietnam plugs. They accept 2 pin flat or round pins.
He thinks he will also struggle to instruct the electrician with what he wants, but his wife is Vietnamese and is bi-lingual, so hopefully they can get around that problem.

A quick search says all of these are used in Viet Nam.

The centre ones come with earth connections as well but I suppose you may have to source them from Europe as well.

And these which accept more than one type of plug but not the earthed C type.

My own education from over 50 years ago suggests that if the supply is not earthed at source, then a local earth can be dangerous.

Well, it depends what you mean by dangerous.
If you cannot use the supply for an earth, then you can only use a properly installed ground electrode (rod) and will have to use Residual Current Devices for Automatic Disconnection of Supply in the event of a fault to earth - what we call a TT installation.
You will, presumably use RCDs anyway these days.

From my own research, I think that the supply is earthed at source to the neutral, but I am not able to verify this.

If by source you mean at the incoming supply to the premises then you will be alright and it will be what we call a TN-C-S supply.
Earth Combined from the transformer and Separate in the installation.

As far as we can determine, no earth wire is supplied with the supply. (at all existing installations examined, no earth wire exists with the supply)

No, it won't be.

Is he being sensible in wiring in an earth to each plug,

I think you really mean each socket - no point having earthed plugs and appliances if the sockets aren't earthed.
As for sensible - I suppose so if there are metal appliances in the building.
Earthing is not a good thing in itself; it is a necessary safety mechanism where needed.

and should he connect this to an earth rod inserted in the ground?

Not if it is allowed to connect to the Neutral supply.

Or is it possible to insist on an earth wire to be supplied with a new supply, (it is a new supply)?

You cannot insist on it in the UK but if you supply the cable they will connect it when installed - just a short bit so you can connect to others.

 

[Mfatic]

Thanks for that.
To summarise, use RCD's,
provide an earth to each socket, switch and light fitting,
keep this earth separate from the Neutral (and Live obviously!) throughout the installation,
connect this earth to an earth rod inserted into the ground.

Does that about cover it?

You are correct that two pin round and flat can be used.
As far as I am aware, three pin plugs are not used or available and he would have to source the sockets and plugs from elsewhere.
As far as I am aware, these are the only ones used
View attachment 164384

 

[EFLImpudence]

Thanks for that.
To summarise, use RCD's,
provide an earth to each socket, switch and light fitting,
keep this earth separate from the Neutral (and Live obviously!) throughout the installation,
connect this earth to an earth rod inserted into the ground.

If they don't let you use the supply Neutral to connect to. There's no point having a rod if they do.

You are correct that two pin round and flat can be used.
As far as I am aware, three pin plugs are not used or available and he would have to source the sockets and plugs from elsewhere.
As far as I am aware, these are the only ones used
View attachment 164384

The socket in that picture is earthed but only the appropriate plugs will fit, including the C type I presume - BUT the earthed C type will not connect the earth connection.

Note the earth connections top and bottom.

The flat plug for appliances that are not earthed.