I plan to build a home in CR next year and am confused about the electrical wiring in Thailand.

What I don't understand is the Neutral leg in Thailand. Here in the US, the left prong (larger) is Neutral, the right side (smaller) is hot at 110V. Ground is at the bottom.

When most/many things here are wired for 220V, there are 2 hot legs and a ground. There is no Neutral. (This is the way my water heater is, some baseboard heaters, the clothes dryer, etc.)

I assumed that in Thailand it's the same way as we do 220V here-as described above, but thinking about it, I may be wrong. Are normal household outlets in Thailand (2 prong plus ground) using 2 hots (at 110V each) and a ground or is it one hot at 220V, a Neutral and a ground? I am aware that most outlets in Thailand are only 2 prong, but I'll be building with only grounded outlets.

I plan when I wire the house to have some outlets dedicated to 110V for the things I bring from the States and the rest to be normal Thailand voltage. I will color code everything to not mix it up. Obviously whichever system Thailand uses as I've described above will change how I wire the house.

Thanks in advance for any advice.

Thailand is (mostly) 3-phase 4-wire so you get 220V between N and L (hot).

I would NOT have dedicated 110V outlets unless you can find a way of absolutely preventing swapping of 220v and 110V appliances (put a different plug on 110V units maybe), colour coding is just too easy to forget (or not know).

You will also need a meaty (expensive) 220-110 transformer, better to use a (cheap) converter on each appliance and permanently attach the US plug to the 110V output.

Don't forget Thailand is 50Hz so US devices with motors may run slow and hot even on 110V.

Thanks for the idea. I'm sure you're right that multiple converters permanantly attached to each cord would be far cheaper than wiring the whole house with separate outlets. I think I'll do that.

On the original question, If I understand you correctly, on a typical Thai 3 prong outlet, One prong is 220V hot (at 50hz), one is Neutral and the third is ground. Is that correct?

Thanks again.

On the original question, If I understand you correctly, on a typical Thai 3 prong outlet, One prong is 220V hot (at 50hz), one is Neutral and the third is ground. Is that correct?

Yup, got it

Useful info here http://crossy.co.uk/wiring/index.html

Thanks again for your advice. I checked out the link and found a great deal of information.