3 Phase Electricity

[Beardog]

If we switch from single phase to 3 phase what all would be affected? I think certain appliances need to be three phase wired. Any sparkies in TV that can help me understand the difference?

Thanks again!!!!!!!!!!!!

[Crossy]

If you're currently on single-phase a switch to 3-phase won't affect your appliances, single-phase appliances derive their power between a phase and neutral.

In your case you would simply treat your modified supply as if it was three single-phase supplies, you'll need a new 3-phase consumer unit / distribution board.

[Beardog]

If you're currently on single-phase a switch to 3-phase won't affect your appliances, single-phase appliances derive their power between a phase and neutral.

In your case you would simply treat your modified supply as if it was three single-phase supplies, you'll need a new 3-phase consumer unit / distribution board.

Thanks Crossy I thought it would be a lot more expensive of a change if my neighbor decides to switch the power to 3 phase.

[Crossy]

Actually, even if on 3-phase from new, it's wise to have single-phase appliances. Loss of one phase will simply kill 30% of your load, whereas if you have 3-phase appliances and lose a phase you could (will) suffer damage

Why would what your neighbour does affect your supply? Unless of course, your current single-phase supply is marginal.

[bankruatsteve]

What appliances are there that can handle 3-phase? (other than mg, ac, and industrial ovens - which most of us would never need).

[Beardog]

His girl decided it would be groovy to build 3-4 rentals on the property. The Sattahib Naval base oversees our district in Bang Saray & we were told we would have to pay as a commercial business & upgrade to 3 phase if more than 4 houses were put on property. We have 2 or one almost being built next to the spare house. I don't think the guest house plan will fly as the original intention was we were looking for(1) set a couple to take buy the land. Chanote not transferred yet due to 1/3 payment in & 3rds 2/3rds) not paid. I was just preparing for a possibility of a power change. I doubt after next week there will be more than 2 houses built as my agreement with Sattahib. Besides It is Colin's girl trying to change things up without his nor our blessings.

I would rather keep the single as it works great & is already super adequate with a 30/100 service & almost no on one the line from the transformer.

[Naam]

What appliances are there that can handle 3-phase? (other than mg, ac, and industrial ovens - which most of us would never need).

in Germany it was mandatory that every gadget that draws more than 1.5 kWh, e.g. washer, dryer, oven, cooking range, aircons had to be three-phase.

[Khonwan]

What appliances are there that can handle 3-phase? (other than mg, ac, and industrial ovens - which most of us would never need).

I run a 9.4kVA welding unit, 12kW shower, and a 3hp motor for a high-pressure sprayer on three-phase (reason: my transformer is 1 mile from my house; 50mm² cables).

[Beardog]

And that is exactly why I inquired. I thought the oven, dryer if you have & pumps needed to be three phase. Now I know!

[lopburi3]

That post was for Germany. This is Thailand and not a part of Germany and three phase is not required. You would likely have a hard time even finding three phase consumer appliances here.

[Crossy]

Just to clarify for the OP.

Since your current 30/100 supply is more than adequate you need do nothing if your neighbour decides to get 3-phase run to his place.

[Naam]

That post was for Germany. This is Thailand and not a part of Germany and three phase is not required. You would likely have a hard time even finding three phase consumer appliances here.

you can get aircons 36k btu as single and three-phase. 48k btu and higher capacity are all three-phase.

[lopburi3]

And you know as well as I that they are not considered normal consumer items here.

[chrgrims]

6 months ago i changed to 3 phase. didnt have to change any appliances, ac or anything else.

[Naam]

6 months ago i changed to 3 phase. didnt have to change any appliances, ac or anything else.

of course not because a three-phase connection consists of three single phases and you are using them "singly". the other way round does not work in case you have some three-phase appliances.

[Beardog]

Thanks for all the responses. I now understand how the 3 phase system works. I love learning!

Nice to know I won't have to upgrade if they decide to go ahead & go on 3 phase.

[chrgrims]

6 months ago i changed to 3 phase. didnt have to change any appliances, ac or anything else.

of course not because a three-phase connection consists of three single phases and you are using them "singly". the other way round does not work in case you have some three-phase appliances.

wish i could change u to 3phase, any change would be an improvement.

[Artisi]

Of course this discussion beggers the question- what is so good about a 3 phase supply in a domestic situation, considering the majority of the worlds house that have electricity connected are single phase.

[Crossy]

Of course this discussion beggers the question- what is so good about a 3 phase supply in a domestic situation, considering the majority of the worlds house that have electricity connected are single phase.

We are not in the majority of the world

The biggest readily available single-phase supply in Thailand is a 15/45 maximum current draw 45 Amps (a bigger 30/100 supply is available in some areas but does not guarantee much http://www.thaivisa.com/forum/Advice-t355261.html). 45A at 220V is about 10kW.

A farang home with say 4 aircons, water heater and water pump will take a 15/45 to its limit, add an electric stove and oven...... The only solution if a 30/100 is not available, 3-phase.

In some rural areas the biggest supply available is a 5/15, for anything bigger than a shed 3-phase at 5/15 will at least get you the equivalent of a 15/45 single-phase.

[longball53098]

Crossy is so correct here.

When we were planning and now built the new house I was faced with this dilema. The local PEA supply in our development was either a single phase of 15(45) or if more demand than 3 phases of the 15(45).My house electrical plans called for at least 3 AC units one of which was 36,000 btu this unit is not installed yet and will require 3 phase power and a water heater for both the kitchen and multi point for the 2 bathrooms plus the usual plugs and lights and pumps. Add a pool system in the future and you quickly have a maximum demand that is approaching 100 amps. The single phase 45 amp service would not meet the demand and needs. Only option is to bring in the 3 phases of 15(45) which essentially triples my supply current. I do not have any devices that require actual 3 phase but I can now distribute from my consumer panel to the entire house and garden up to 150 amps if needed. Balancing the load across the 3 phases is needed. We live in a different environment here as compared to my home in the USA. There we could routinely get 200 to 300 amps from the electric utility and they were happy to provide it. Here you do not get what you want but what the area can suppy.

[katabeachbum]

Crossy is so correct here.

When we were planning and now built the new house I was faced with this dilema. The local PEA supply in our development was either a single phase of 15(45) or if more demand than 3 phases of the 15(45).My house electrical plans called for at least 3 AC units one of which was 36,000 btu this unit is not installed yet and will require 3 phase power and a water heater for both the kitchen and multi point for the 2 bathrooms plus the usual plugs and lights and pumps. Add a pool system in the future and you quickly have a maximum demand that is approaching 100 amps. The single phase 45 amp service would not meet the demand and needs. Only option is to bring in the 3 phases of 15(45) which essentially triples my supply current. I do not have any devices that require actual 3 phase but I can now distribute from my consumer panel to the entire house and garden up to 150 amps if needed. Balancing the load across the 3 phases is needed. We live in a different environment here as compared to my home in the USA. There we could routinely get 200 to 300 amps from the electric utility and they were happy to provide it. Here you do not get what you want but what the area can suppy.

another solution would be to reduce maximum demand by replacing 3 waterheaters each needing probably 3500 watt or more, with one boilertank and hotwaterpipes needing only 2200 watt.

30/100 amp meters onephase seem to be available in most suburb and town areas

[longball53098]

Crossy is so correct here.

When we were planning and now built the new house I was faced with this dilema. The local PEA supply in our development was either a single phase of 15(45) or if more demand than 3 phases of the 15(45).My house electrical plans called for at least 3 AC units one of which was 36,000 btu this unit is not installed yet and will require 3 phase power and a water heater for both the kitchen and multi point for the 2 bathrooms plus the usual plugs and lights and pumps. Add a pool system in the future and you quickly have a maximum demand that is approaching 100 amps. The single phase 45 amp service would not meet the demand and needs. Only option is to bring in the 3 phases of 15(45) which essentially triples my supply current. I do not have any devices that require actual 3 phase but I can now distribute from my consumer panel to the entire house and garden up to 150 amps if needed. Balancing the load across the 3 phases is needed. We live in a different environment here as compared to my home in the USA. There we could routinely get 200 to 300 amps from the electric utility and they were happy to provide it. Here you do not get what you want but what the area can supply.

another solution would be to reduce maximum demand by replacing 3 water heaters each needing probably 3500 watt or more, with one boiler tank and hot water pipes needing only 2200 watt.

30/100 amp meters one phase seem to be available in most suburb and town areas

No 30/100 here in our place/area. 15/45 is max.

I don't have 3 water heaters. Only two, one of which is very high current draw Stiebel unit. I did not want to heat water all day every day in a boiler and use very little hot water plus the added expense of the copper piping all over the place. Why pay to heat water that is not used. If I still lived in the US where supply water is very cold in the northern states and a person uses may gallons of hot water I would have done things differently I'm sure

Actually, I only posted this info to say that sometimes 3 phase is needed. Most folks do not have actual 3 phase equipment in the home except possibly for the bigger AC units. But most folks have many whiz bang gadgets that quickly eat up the available amps from a single phase.

Edited April 13, 2010 by longball53098

[Naam]

Of course this discussion beggers the question- what is so good about a 3 phase supply in a domestic situation, considering the majority of the worlds house that have electricity connected are single phase.

the majority of homes built after 1970 in central Europe have a three-phase supply installed. standard in Germany is 3x60amps which -unlike Thailand- is the maximum per phase even for starting currents. you draw more and the fuse pops. only the electrical supply company can change the fuse which is located in a sealed box (you break the seal and try to replace the fuse, you are in big trouble with the law).

then there are homes in Thailand (like mine) with 19 (nineteen) aircon units, pool pump, irrigation pump, pond filter pump, waterfall pump, deepwell pump, house water supply pumps and a variety of other electric appliances which -if all gadgets run in sync- would draw in excess of 150 amps and if they'd start in sync most probably >500 amps.

[katabeachbum]

Crossy is so correct here.

When we were planning and now built the new house I was faced with this dilema. The local PEA supply in our development was either a single phase of 15(45) or if more demand than 3 phases of the 15(45).My house electrical plans called for at least 3 AC units one of which was 36,000 btu this unit is not installed yet and will require 3 phase power and a water heater for both the kitchen and multi point for the 2 bathrooms plus the usual plugs and lights and pumps. Add a pool system in the future and you quickly have a maximum demand that is approaching 100 amps. The single phase 45 amp service would not meet the demand and needs. Only option is to bring in the 3 phases of 15(45) which essentially triples my supply current. I do not have any devices that require actual 3 phase but I can now distribute from my consumer panel to the entire house and garden up to 150 amps if needed. Balancing the load across the 3 phases is needed. We live in a different environment here as compared to my home in the USA. There we could routinely get 200 to 300 amps from the electric utility and they were happy to provide it. Here you do not get what you want but what the area can supply.

another solution would be to reduce maximum demand by replacing 3 water heaters each needing probably 3500 watt or more, with one boiler tank and hot water pipes needing only 2200 watt.

30/100 amp meters one phase seem to be available in most suburb and town areas

No 30/100 here in our place/area. 15/45 is max.

I don't have 3 water heaters. Only two, one of which is very high current draw Stiebel unit. I did not want to heat water all day every day in a boiler and use very little hot water plus the added expense of the copper piping all over the place. Why pay to heat water that is not used. If I still lived in the US where supply water is very cold in the northern states and a person uses may gallons of hot water I would have done things differently I'm sure

Actually, I only posted this info to say that sometimes 3 phase is needed. Most folks do not have actual 3 phase equipment in the home except possibly for the bigger AC units. But most folks have many whiz bang gadgets that quickly eat up the available amps from a single phase.

it was just my input on how to manage without 30/100 onephase or 15/45 threephase 4 wire.

In one of my properties I have a 200 litres boiler tank on the roof with 2 x 1100w heater. I conected a meter for some weeks to see how much electricity it draws, and it was very little.

30 C temp on water in, hotwater set at 80 C and tank in 25-38 C airtemp all year around, makes it very cheap hotwater. so cheap a solar heating unit would not be costeffective at any point if lifetime is less than 20 years

In another home I have 3 x 3500w heaters, and I am sure they need more electricity in a year.

copperpipes are not needed for hotwater. ppr works fine for 50-80 years and is almost as easy to install as pvc

[Crossy]

In one of my properties I have a 200 litres boiler tank on the roof with 2 x 1100w heater. I conected a meter for some weeks to see how much electricity it draws, and it was very little.

30 C temp on water in, hotwater set at 80 C and tank in 25-38 C airtemp all year around, makes it very cheap hotwater. so cheap a solar heating unit would not be costeffective at any point if lifetime is less than 20 years

In another home I have 3 x 3500w heaters, and I am sure they need more electricity in a year.

Interestingly, the US Department of Energy reckons that tankless on-demand water heaters are more energy efficient than tank heaters, http://www.energysavers.gov/your_home/wate...m/mytopic=12820

For homes that use 41 gallons or less of hot water daily, demand water heaters can be 24%–34% more energy efficient than conventional storage tank water heaters. They can be 8%–14% more energy efficient for homes that use a lot of hot water—around 86 gallons per day. You can achieve even greater energy savings of 27%–50% if you install a demand water heater at each hot water outlet.

The physics says that, all other things being equal, the only difference in energy consumption is the power used to make up the losses in a tank heater, with good insulation that should be minimal.

[longball53098]

Sorry I just added my post as this topic is about 3 phase and single phase and the need for one or the other. Hot water supply and pipes and cost are a whole other topic. We all make our choices with the info we get from whatever sources we choose to use.

[katabeachbum]

In one of my properties I have a 200 litres boiler tank on the roof with 2 x 1100w heater. I conected a meter for some weeks to see how much electricity it draws, and it was very little.

30 C temp on water in, hotwater set at 80 C and tank in 25-38 C airtemp all year around, makes it very cheap hotwater. so cheap a solar heating unit would not be costeffective at any point if lifetime is less than 20 years

In another home I have 3 x 3500w heaters, and I am sure they need more electricity in a year.

Interestingly, the US Department of Energy reckons that tankless on-demand water heaters are more energy efficient than tank heaters, http://www.energysavers.gov/your_home/wate...m/mytopic=12820

For homes that use 41 gallons or less of hot water daily, demand water heaters can be 24%–34% more energy efficient than conventional storage tank water heaters. They can be 8%–14% more energy efficient for homes that use a lot of hot water—around 86 gallons per day. You can achieve even greater energy savings of 27%–50% if you install a demand water heater at each hot water outlet.

depends on climate, insulation of tank and insulation of hotwaterpipes

as sayd, in LOS, average 30 C on cold water in and tank in airtemp 25-35C

Little energy to heat water, little to keep it hot

[Naam]

The physics says that, all other things being equal, the only difference in energy consumption is the power used to make up the losses in a tank heater, with good insulation that should be minimal.

not to forget the length of pipe from boiler to usage. when the slab of my last home in Florida was poured i was abroad. but a neighbour made photos of the water pipes to be embedded in the concrete. none of the hot water pipes were insulated! result: when i wanted to have a shower i switched on the hot water, poked my nose, went for a pee, undressed and then the water temperature was about right

[katabeachbum]

The physics says that, all other things being equal, the only difference in energy consumption is the power used to make up the losses in a tank heater, with good insulation that should be minimal.

not to forget the length of pipe from boiler to usage. when the slab of my last home in Florida was poured i was abroad. but a neighbour made photos of the water pipes to be embedded in the concrete. none of the hot water pipes were insulated! result: when i wanted to have a shower i switched on the hot water, poked my nose, went for a pee, undressed and then the water temperature was about right

and your slab was hot

[Crossy]

Sorry I just added my post as this topic is about 3 phase and single phase and the need for one or the other. Hot water supply and pipes and cost are a whole other topic. We all make our choices with the info we get from whatever sources we choose to use.

Yup, we've whizzed off-topic. That said, I think we've exhausted the "To 3-phase or not to 3-phase that is the question" discussion