Electrical 3 Phase House Questions

[carlyai]

I've inherited a 3 phase 15(45) meter from my brother in law's old rice mill that is no more. I have read all the forum pages about electrics and Crossy's pages too. Thanks very much. I am building a house outside Kuchinarai and am up to the electrical installation stage. Reading what has been written before I have come up with a plan for the consumer unit, cabling etc for the house. The 3 phases will feed a main 100A 3 pole breaker. The red, blue and yellow phases will feed separate 63A breaker, 63A RCD and then 10 other breakers ranging from 32A to 16A. I have tried to apply the correct formulas to get the correct rated cables and breakers.

i had to make a quick trip back to Pattaya for some skin checks and put into practice something that Crossy said. I had an electrician put a correct SafteyCut in out house and upgrade the earths and some cable sizes. Lucky we did as the electrician drilled through a live wire with his metal drill and sweaty hand on the wall with the ensuing 'pop' and brown smell and the safetycut working 'clack'. One thankful electrician, and unsued house owner.

While talking to the electrian I went over my plan and we did some more load phase current calculations and he said my loads were not balanced enough. He also said that electricians would try and wire the house in sections, ie the living room, kitchen, tv room and second bedroom etc.

I am back in Kuchinarari and trying to balance the phase loads and change the wiring plans to separate the house in sections like suggested. So my questions are: as I am not using three phase equipment or motors, why can't I look at my three phases as 3 different houses (like I can see the houses in the street are hooked to a single phase, but the 3 phases are used), so the red, yellow and blue phases can be 3 separate identities but in the one house? i will try and get the phases balanced, but if I end up with say a maximum demand on the red phase of 72A and the yellow of 60A and the blue 65A is that OK?

[gamini]

How many air conditioners have you got? 3 or more you would need three phase

[NeverSure]

Good lord. Buy a proper meter and panel. They aren't expensive. You can get into all kinds of trouble and headaches.

I don't know if the conventional 220 in Thailand is double phase or 2x single phase (as it is in America) but you have so many different electrical things to run that need standard voltage that you need to start out right.

Is there actually 3 phase power to your home site? If so, you need to get the electric company to fix that.

[NeverSure]

Double post, sorry.

Edited April 22, 2014 by NeverSure

[ubonjoe]

I think this needs be to moved to the electrical forum

Nothing specific for Isaan in topic.

[DJH77]

Thre Phase power in Australia is 415 volts. Three Phase in Thailand is simply 3 x 220 volt lines from the transformer to your switch board. The house must be wired so that each of the 3 lines carries around 33% of the load. If not your electricity bill will be higher according to the electricity company. This way when the local power goes off you may only loose 1 phase which cuts the power to that section of the house on that particular line and the other 2 still function. At least thats how it works at my place. Each electrical circuit or run in the house goes to a maximum of 8 low voltage lights and back to the Breaker for that circuit at the switch board. My house has 250 lights and 70 double power points, plus 6 Aircon units. These are run to 3 seperate switchboards with approx 70 individual breakers for the entire house. If 1 breaker trips, which may happen once a year, only that 1 run of lights goes off, not one third of the house. I'm a Plumber, Not an electrician and never do anything electrical apart from change the occasional globe. In the case of the globes, i still have about 50% of the origional globes still going after 10 years, i put this down to a constant and even rate of power to the circuits thus eliminating surges which blow the globes.

[Crossy]

Duplicate thread, let's keep everything in one place, here http://www.thaivisa.com/forum/topic/720675-electrical-three-phase-house-wiring/