New House build electrical supply

[d0om4gloom]

Hello, its been a long time since i was on the forum after moving back to UK in 2010.  However light is at the end of the tunnel, i am building a house in Chiangmai and have reached the electrical stage.  Im looking for advice:

 

In UK the domestic electrical supply is typically 100amp single phase and the earth is literally a pipe in the ground.  It might be lost in translation but the builder has said i need 3 cables into the house because we need multi-phase supply.  I dont understand, is that what he really means ?   It a 4 bed, 5 aircon with western kichen appliances house

 

What about the size of supply, 100amp single phase domestic supply in UK has 25mm cables (typically),  what does thailand do ?

 

Then theres a really old supply into the plot which was sub-divided from next door.  The main pole is next door and the existing cables come across the road to their pole then drop down to our sub-division.  Builder says we need our own pole.  I dont see it, the neighbors pole is just 1 meter from our boundary.  The neighbour doesnt care, do we really need our own pole ?

 

Last, on the lighting I am used to using GU10 connectors with mains voltage on LED bulbs.   Thailand seems to use MR16,  we can get hold of GU10 so i’m more inclined to go with them.  However, if they fit MR16, isnt that 12v DC ?  What do they normally do, fit a transformer at every single light fitting ?  We have 80 of them so if I need 80 transformers then GU10 is definately cheaper and i can get the bulbs easily as well.  What recommendation does anyone have and the reasoning ?

 

Hoping you can help me 

Thankyou

[Crossy]

Actually your UK supply is far more likely to be fused at 60 or 80A with TNS or TNC-S earthing even if the supply is overheads.

 

Anyway, to Thailand.

 

Unless you are in a major conurbation the largest common supply is a 15/45 meter which would be on a 50A breaker (about 11kW total). Some areas can get 30/100 (100A) meters but they are not common in rural locations.

 

If your prospective load is over that then 3-phase 15/45 is the way forwards (33kW total). 3-phase requires 4 wires from the street. Personally, even if the load was within the single-phase limits I would go 3-phase (we didn't, hindsight is 20-20) as the most common supply failure is loss of 1 phase (it always seems to be the one we are on of course), with a 3-phase supply you still have 2/3 of your stuff working.

 

The minimum size of the supply conductors is determined by the supply authority, PEA would expect 10mm² on a 15/45 meter. But unless you have a very short run volt-drop would mean larger cables are needed.

 

Similarly the authority will decide if you need a pole for the meter, it matters not what "next door have", you do what they say or you don't get a supply. 

 

If you post a list of your intended appliances (aircon, water heaters, kitchen) we can do a rough and ready prospective load guesstimate. Any pool, man-cave, hobby shed?

 

There's some useful info in this thread, but do verify with the local supply authority.

 

 

For your lighting etc. Rule No-1 would be to use what you can get locally. 220V LEDs are readily available in various formats, but if you want to go LV then group the fittings and give each group a transformer.

 

This PEA document is handy to give to your sparks 

Groundwire Mk2 book-Manual.pdf

[Blue Muton]

cue @Crossy........

[Blue Muton]

6 minutes ago, Crossy said:

Actually your UK supply is far more likely to be fused at 60 or 80A with TNS or TNC-S earthing even if the supply is overheads...............

 

 

 

55

 

You were just too quick on the draw for me!

[d0om4gloom]

Oh wow thankyou for that information, i can see its very different and now understand the builders comments.  I really appreciate the reply

[d0om4gloom]

Oh i should have said we are in central Chiangmai.  I saw something from electricity company about 100amp supply but now i realise that doesnt mean its available to us.  All starts to make sense

[bankruatsteve]

Hopefully, your "electrician" can give you a design (power points, lighting, switches, circuits, etc.).  If so, you could post that for critique if you want.  If he can't, you might want to look for someone who can.

[DUNROAMIN]

9 hours ago, d0om4gloom said:

Hello, its been a long time since i was on the forum after moving back to UK in 2010.  However light is at the end of the tunnel, i am building a house in Chiangmai and have reached the electrical stage.  Im looking for advice:

 

In UK the domestic electrical supply is typically 100amp single phase and the earth is literally a pipe in the ground.  It might be lost in translation but the builder has said i need 3 cables into the house because we need multi-phase supply.  I dont understand, is that what he really means ?   It a 4 bed, 5 aircon with western kichen appliances house

 

What about the size of supply, 100amp single phase domestic supply in UK has 25mm cables (typically),  what does thailand do ?

 

Then theres a really old supply into the plot which was sub-divided from next door.  The main pole is next door and the existing cables come across the road to their pole then drop down to our sub-division.  Builder says we need our own pole.  I dont see it, the neighbors pole is just 1 meter from our boundary.  The neighbour doesnt care, do we really need our own pole ?

 

Last, on the lighting I am used to using GU10 connectors with mains voltage on LED bulbs.   Thailand seems to use MR16,  we can get hold of GU10 so i’m more inclined to go with them.  However, if they fit MR16, isnt that 12v DC ?  What do they normally do, fit a transformer at every single light fitting ?  We have 80 of them so if I need 80 transformers then GU10 is definately cheaper and i can get the bulbs easily as well.  What recommendation does anyone have and the reasoning ?

 

Hoping you can help me 

Thankyou

Most important here, make sure your electrician is qualified to do the work, alot of back yard boys here.

[Crossy]

8 hours ago, d0om4gloom said:

Oh wow thankyou for that information, i can see its very different and now understand the builders comments.  I really appreciate the reply

 

It's why we have this forum, loads of local knowledge here, ask any questions you like (even "stupid" ones).

 

It's important to understand that the supply infrastucture is much less rigid here than "back home". 

 

We have a 15/45 meter so theoretically we should be able to draw 45A and stay within the +-10% spec. In reality the source impedance (measured) is around 0.5 ohms so at 45A that's a drop of 22.5V, already marginal for a 220V supply, but when the other village loads have already pulled the supply down to 200V or so ...

 

The "standard" PEA response to complaints is "you have electric, no problem".

[Maybole]

Check the number of sockets offered, most thai house have only a few , hence the ubiquitous used of trailing extensions. When I built our new house 3 years ago I specified at least 4 double sockets in each room and 6 in the kitchen. Our electrician was surprised and at first was reluctant to put in so many. He had to have his mouth stopped with gold.

[sometimewoodworker]

10 hours ago, Maybole said:

Check the number of sockets offered, most thai house have only a few , hence the ubiquitous used of trailing extensions. When I built our new house 3 years ago I specified at least 4 double sockets in each room and 6 in the kitchen. Our electrician was surprised and at first was reluctant to put in so many. He had to have his mouth stopped with gold.

So you were very economical with the numbers 

part of 1 wall in our living-room kitchen 

including a cute random kitty 

[Crossy]

2 hours ago, sometimewoodworker said:

part of 1 wall in our living-room kitchen 

 

There are none in the rest of the house, sparks was economising on cable

[gunderhill]

I  would also add surge protection over under  voltage - lightning protection.

[sometimewoodworker]

3 hours ago, Crossy said:

 

There are none in the rest of the house, sparks was economising on cable

You must be correct and the others (over 100) are all powered by his imagination ???? 

Edited February 27, 2021 by sometimewoodworker

[jimmym40]

Sent you a PM.     Maybe you didn't get/notice it.