3-Phase Residential Electricity?

[TongueThaied]

First off, please, I am not interested in a bunch of gratuitous global warming or other environmental comments. I am aware of all these considerations. However, I do not like creating bottlenecks nor burning bridges. Nobody knows for sure what the future holds.

I am getting ready to order power for a house I will begin soon. The question is, should I go for 3-phase or stay with the usual single phase? Though I live in a small village, 3-phase is readily available as I will be building right next to the public water supply, which employs pumps driven by 3-phase motors. I hope to have input on this from my favorite electrical guru, Crossy.

Most of you will say, whoa, why the hell would you need, let alone want 3-phase. Here we go. I am building a typical American energy hog style house. It will have an: oven (3,000 W), microwave (1,400 W), refrigerator (2,200 W), dishwasher (2,400 W), hot water washer (2,200 W), clothes dryer (2,250 W), 3 multipoint water heaters (10 KW each), 7 air conditioners (9,000 W, total), etc. There will be a <deleted> lot of electrical outlets, can lights and ceiling fans, as well as a water pump and possibly a pump-driven waterfall. There will be a wood shop. I do not offer this list for purposes of calculating anything, but only for purposes of creating belief when I say the maximum demand is large. How large?

I used Crossy's "Maximum Demand Estimation in a Single Domestic Electrical Installation" (www.crossy.co.uk/wiring/.../Maximum_Demand_Estimation.doc), and came up with a "Maximum Demand" of roughly 166 amps at 220V. (Of course turning everything on at exactly the same time would draw MUCH more).

In addition, I will have a 42 inch exhaust fan that can be ordered in either 220V or 380V. For motors like that, 3-phase is more efficient. Everything else is single phase.

The largest single phase 220V watt hour meter I can find is the Mitsubshi MF-33E(U) 1P2W rated at 50A(150A). I can't even find a single phase meter here that would support 166 amps of continuous draw.

On the other hand, Mitsubishi's MH-36H(E) comes in a 380V 3-phase, 4 wire rated at 30/100A, which can handle up to 172 amps of current split into three 220V single-phase trunks.

Okay, here's the reality: I am NOT really an energy hog. I am building into this house everything I might want. This is it -- the last house I will ever build. I am putting in everything I might want or even need as my wife and I age. I don't like air conditioning and will seldom use it, although if I have guests that like it, I may turn on all seven of them at the same time. Normally, I will probably use the air conditioners only sporadically in the hottest two months, but will turn them on once a month to keep the bearings in good order and to dry out the house air.

I won't use the oven very often. I usually wash clothes with cold water, and I like my baths cold. I will probably continue to hang clothes out to dry. I turn off the lights in a room when I leave it. My wife is of a similar view on all this.

Nonetheless, it is possible that with guests visiting, all the air conditioners might be running, while my wife is baking a cake in the oven, having just started a load of clothes in the washer, while the dryer dries a previous load, with one guest in each bathroom each running hot water, all while I'm out in the shop running lumber through the planer. In other words a "perfect electrical storm" with little odds of occurring, but it could.

With three phase, the lines in would be smaller (easier to handle) and I could run them into a 380V master panel, which would feed the 3-phase fan and three 220V sub-panels. I could have all the appliances on one sub-panel, all the lights, outlets and ceiling fans on another, and the shop on its own. There would never be any bottlenecks -- or perfect storms.

The downside would be greater upfront expense setting it all up. I do not know if there is any extra monthly cost imposed by the electric company for 3-phase.

The fact is, if I had the 150 amp 220V meter, it is doubtful I would ever actually fully tax it.

So, what? Open the door for future hoggish behavior? Or go the conservative route. I only have one chance to get it right. Any opinions about this? Your thoughts would be appreciated.

And for those who still want to bust my balls about energy consumption, first consider that I have been living for three years in a "very Thai" house with a 5(15A) meter, and our electric bill is seldom over 1,000 baht a month.

Mitsibishi Electric Meter.pdf

Mitsibishi Electric Meter 3-phase.pdf

Edited August 19, 2012 by TongueThaied

[TongueThaied]

Error, please delete

Edited August 19, 2012 by TongueThaied

[villagefarang]

I’m not sure what the problem is. Go ahead and go for the three phase. That is what I did.

[kaspercat]

Go with the 3 phase too. I did. It does help when the power goes out. Usually, I find at least some of my rooms still have lights and AC. We seperate out outlets and lights to be on different phases and only the big ac, do I use the 3 phase.

[TongueThaied]

Go with the 3 phase too. I did. It does help when the power goes out. Usually, I find at least some of my rooms still have lights and AC. We seperate out outlets and lights to be on different phases and only the big ac, do I use the 3 phase.

Thanks! I had no idea that the power might go off for only one or two of the lines; I figured all or nothing. With this as the case, one could set up the water pump and some lights for switching from one circuit to another. Ordinarily, I don't care if the power goes off, but in the new house, I'll be dependent on the pump and would hate to be left high and dry in the shower all covered with soap!

Edited August 19, 2012 by TongueThaied

[monty]

Just a remark, it looks from your op that the original house still has to get built.

Fyi, you can only apply for a "proper" meter once you have the house book. Till then you're stuck with a "temporary" meter.

And inquire at the pea, as it is not always a given that the existing overhead lines can support another high amp meter. All depends on what the current load is on the local transformer...

Sent from my GT-I9001 using Thaivisa Connect App

[JeffreyMcCollum]

My 200 amp service was single in my last home with pool Jacuzzi etc.

3 phase here in Thailand is usually done because it is cheeper for the power company to run lower rated equipment and smaller lines. Do as you wish, usually it is told to you by the power authority what you will get. In my 10 years doing electrical work here I find more problems with the 3 phase than the single, and thouse my home is single (however with 2 braker boxes, 1 up stairs and 1 down just to be easier for me)

[Crossy]

PEA will not normally supply more than a 30/100 be that single or 3-phase.

You need to talk to your local office to see what they can do, with such a big load you may end up with having to get your own transformer = $$$

[snarky66]

The wood working shop pretty much sealed the deal for 3 phase power. Enjoy. My Danish neighbor brought all his appliances with him from Denmark & he was stuck wiring up 3 phase. Very satisfactory.

Some of you other folks need to consider buying an emergency generator. If the PEA is unable to fulfill their mandate.

[farang62]

3 Phase is the way to go. not cheaper power wise but more convenient here in Thailand. Remember a Watt is A Watt and that is what the meter measures. The only worrying thing is if you are on the same transformer as the "water Plant" you may experience low voltage and power surges if the power company "primary voltage" varies. This will cause the pumps at the water plant to draw more power and cause power spikes when the motors start and stop.

The best bet would be your own transformer, make sure all 3 phase devices have "Phase Loss Protectors" installed, pool and water pump have low voltage protection installed, refrigerators should have Protectors (protects against starting before the pressures have equalized in the compressor and protect against low and over voltage) on them. I also install Spike Suppressors installed on each phase at the panel. This way your whole house is protected against spikes and surges. The 30/100 amp meter will do fine. I doubt if your power will ever exceed 40 amps per phase, reason not everything runs or starts at the same time, even with a power outage. I suggest you have you electrician install a small plastic box at the Main panel with 3 lights on it indicating each phase, that way you will not go crazy trying to find out problems due to a phase loss. A great trouble shooting tool and requires no meters or access to power panel by inexperienced people.

I also suggest you take a look at at your breaker panel, the color stripes in the edge indicate the phase the breaker is on. Basically they run horizontally 1st row one phase, 2nd row second phase, third row 3rd phase, the next row starts over avian. Comparing the lights with the breaker will tell you which circuits have no power.

It is best the the light colors match the corresponding breakers in the panel.

Last but not least make very sure the breaker panel has a proper circuit directory in English, nothing worse than having to flip breakers off and on to disconnect the power some where in the house. And always check, test and check again the power is off before working on any connection.

Please remember that 3 phase voltage is 380-400 volts from phase to phase, 220 volts phase to Neutral, and make very sure they drive a 1.8 meter 5/8" ground rod that will be connected to your breaker panel ground bar. remember the ground rod and the connection to it Must be visible, don't bury it leave at least 6cm above ground with the ground wire connection viable.

Just my 2 cents wort, these are the basic rules we follow when we do a house and have never had an electrical problem.

On foreign appliances, my advice if there is no service dealer in Thailand don't buy it, waiting 6 months for a part is frustrating to say the least.

Good luck with your new home.

[TongueThaied]

Thanks for all the comments!