3 Phase Cheaper Monthly Than Single Phase?

[dave111223]

Note that I have very little electrical knowledge.

I currently live in a 3 room condo and use about 1000units of electricity (costs about 4000THB per month)

I'm having a house built this year and it will be much bigger than the condo so i was concerned about a crazy electric bill. However I was talking to my aunt-in-law who has a 4 story house (7 airconditioners) but only uses about 1,100 units per month!

She has 3 phase electric setup and a 30amp meter. Our house that we are building will only be single phase. And our condo is currently using a 15amp meter.

So some questions:

1) Does 3 phase actually use less units of electricity?

2) Does the meter amp size affect the units used? (For example i've heard that if you have a 15amp meter and use over a certain about of power it does not accurately measure the units, and spins too fast)

3) Is there anything else i should consider about single phase vs. 3 phase? Or meter etc..?

[InterestedObserver]

1. NO

2. NO

3. Ask PEA where you are building your house what service size they can supply in the way of electrical capacity, both single and three phase. Compare that with your anticipated total demand.

Are you certain that somebody else has not tapped into your condo electric meter, 1000 units per month is a lot for a three room condo unless you run your air conditioning all the time. You are also paying a high rate per unit of electricity.

Edited January 1, 2012 by InterestedObserver

[dave111223]

Hmm, i'm fairly certain that no one is using our meter because we had the meter installed when we bought the condo, so someone would have had to hook into it at a later date, and the meter is visible from our door. Wheel on the meter seems to stop/almost stop when turning off most appliances.

We run 2 airconditioners at night. 2 computers most of the day, fridge, TVs etc..

Can you please explain further for this: "You are also paying a high rate per unit of electricity." When i looked at my aunts bills she was paying the same unit rates as on our bill?

Is there a way to get a lower rate?

[Naam]

Can you please explain further for this: "You are also paying a high rate per unit of electricity." When i looked at my aunts bills she was paying the same unit rates as on our bill?

your aunt has airconditioners but she does not use them. as simple as that.

[Crossy]

You are also paying a high rate per unit of electricity.

??? About 3.5 - 4 Baht a unit is the MEA / PEA rate once all the surcharges and taxes have been applied.

Agree, 1000 units a month seems excessive but much depends upon the temperature he's got those A/C units set to, you don't get Arctic conditions for nothing.

To answer the OPs questions.

1. No.

2. No, but serious overload will cause meters to mis-read, you can bet they won't read low.

3. Do a basic maximum demand calculation then talk to MEA / PEA about the supply they can provide to meet your needs.

[eriksen]

HELP PLEASE

you will laugh but this situation is true!!

A few of us have houses, and many have apartments.. all going through a meter and then subdivided by the owner..

AND CHARGED AT AROUND 7.5 THB/unit..... how does that rock you? we estimate the cost at 3.5THB unit...

and for you that don't think in the math world... the biggest invoice has been over 8000 THB for one month.. and others in a 2 bed condo over 12000 THB/month... for only 2 people...

so we simply want our own goverment meters... how to do?

the local phuket town official simply says there are not slot left on the local transformer.. yeah right... (new transformer more than 100 000 THB) is he getting paid off? what do you think? (we would love to see him fires/charged/go to jail,

we need to go higher... you cant tell me if a thai made a house they would say this..

anyone have any knowlage in this field would be GREATLY APPRECIATED..

[Crossy]

Eriksen, nobody is laughing here, overcharging for power and water by landlords is endemic, we're lucky in that our condo has a PEA meter so there's no additional charge.

If you do the maths PEA rate comes out at slightly less than 4 Baht a unit.

Sadly I don't think there's much you can do about it other than move or ask your landlord to consider a reduction, and we all know where that will get you

Unlike the UK there is no regulation limiting the rate that a landlord can charge for power, he can of course also limit whether he allows you or PEA to provide government power bypassing his nice little earner.

[InterestedObserver]

I live in a condo in Pattaya, run the aircon 12 hours per day, and the condo/PEA bill comes in at around 3.5 baht per kWh.

[monty]

Electrics are charged at a sliding rate, i.e. the first few units are free, the next block at a low price until you use enough to hit the highest rate.

Resulting in heavy users getting a higher cost/unit.

3 phase or single does not change consumption, nor price.

They do however have TOU meters, where cost during peak times is a bit higher ( 5 B/unit, weekdays 9 am till 10 pm), but signifficantly lower at the off peak times, under 2 B/unit.

Used to be available only to customers on HV i.e. own transformer, but I think it's now easier to get...

Depending on your usage profile this could mean substantial savings.

Posted with Thaivisa App http://apps.thaivisa.com

[bankruatsteve]

Anybody know how 3-phase meters handle unbalanced loads? ie: would it take the highest using phase x 3?

Edited January 7, 2012 by bankruatsteve

[InterestedObserver]

Anybody know how 3-phase meters handle unbalanced loads? ie: would it take the highest using phase x 3?

A 3-phase, 4-wire kWh meter measures total energy in all three phases, not a X3 calculation, just as long as it conforms with Blondel's Theorem.

Edited January 7, 2012 by InterestedObserver

[edgarfriendly]

Electrics are charged at a sliding rate, i.e. the first few units are free, the next block at a low price until you use enough to hit the highest rate.

Resulting in heavy users getting a higher cost/unit.

3 phase or single does not change consumption, nor price.

They do however have TOU meters, where cost during peak times is a bit higher ( 5 B/unit, weekdays 9 am till 10 pm), but signifficantly lower at the off peak times, under 2 B/unit.

Used to be available only to customers on HV i.e. own transformer, but I think it's now easier to get...

Depending on your usage profile this could mean substantial savings.

Posted with Thaivisa App http://apps.thaivisa.com

Electrics are charged at a sliding rate, i.e. the first few units are free, the next block at a low price until you use enough to hit the highest rate.

Resulting in heavy users getting a higher cost/unit.

3 phase or single does not change consumption, nor price.

They do however have TOU meters, where cost during peak times is a bit higher ( 5 B/unit, weekdays 9 am till 10 pm), but signifficantly lower at the off peak times, under 2 B/unit.

Used to be available only to customers on HV i.e. own transformer, but I think it's now easier to get...

Depending on your usage profile this could mean substantial savings.

Posted with Thaivisa App http://apps.thaivisa.com

Interesting !!

Does anyone have any further info regarding these TOU meters?

my bill is currently around B9000 p/m much less if AC is off.

but as i only use it at night i'd really get a benefit off the cheaper rates.

[electau]

The answer is NO.

Eg.

Consumption eg of 18kWh per day on a single phase supply with a single phase meter is the same as on a three phase supply with a three phase meter.

If you want to reduce your consumption costs you should consider a different tariff but one doubts if this is available in Thailand for residential consumers.

[Khonwan]

I have three phase and own transformer. I cannot recall the exact figures now but analysed it 2 or 3 years ago: my unit cost is lower than the average unit cost that will be paid by most expats on single phase but my standing charge is more expensive than theirs. From memory, I would have to be paying around Bt15,000 per month before my energy cost would work out cheaper than a similar single phase bill of that amount, i.e. at that amount, my average cost of units inclusive all charges would be cheaper than single phase. This, of course, ignores the initial costs of the transformer, etc.

[electau]

I have three phase and own transformer. I cannot recall the exact figures now but analysed it 2 or 3 years ago: my unit cost is lower than the average unit cost that will be paid by most expats on single phase but my standing charge is more expensive than theirs. From memory, I would have to be paying around Bt15,000 per month before my energy cost would work out cheaper than a similar single phase bill of that amount, i.e. at that amount, my average cost of units inclusive all charges would be cheaper than single phase. This, of course, ignores the initial costs of the transformer, etc.

What is your cost per kWh ? You are on a different tarriff structure and not on a residential rate. You may have a max demand charge. You state that you own the transformer, one thinks that you paid for the capital cost and it is the property of the PEA along with the metering.

If you want to reduce your electricity consumption set your airconditoners to 25C and use the only when required. Have an audit carried out on your electricity useage.

[Khonwan]

Electau, I’m on schedule2.1.1; rates: http://www.pea.co.th/rates/Rate2011.pdf. My transformer, their meter. I don’t want to reduce my consumption. I have no air-conditioners; I designed my house with 5-meter high ceilings. My monthly bill is usually for around Bt3,300. My comment above about having to pay around Bt15,000 per month to achieve a cheaper total cost per unit was based on my poor memory (as mentioned) and was probably inaccurate. I’ve prepared a new spreadsheet calculator based on the current rates as sourced above. These rates show that at 913 units, my total cost per unit starts to become cheaper than the normal single-phase tariff; this ignores the initial capital outlay.

The attached calculator can be used by all who are using single-phase 220V directly billed by PEA/MEA (the vast majority of electricity users in Thailand), and also people such as myself who have installed their own transformers (supplied from high voltage of 22-33kV) putting out 230/400V.

Khonwan's Electricity Bill Calculator.xls

[electau]

Khonwan #16.

Your average daily consumption is 30 kWh. That is very high for a residential installation with no airconditioning.

[Khonwan]

Electau, I agree but I have no reason to suspect that it is incorrect. Electricity theft is ruled out since my entire 1-mile+ long installation is very remote from anyone else. I’ve ruled out leakage by testing. I have 6 medium to large TV’s often on at the same time; 7 satellite decoders; PC; medium fridge-freezer; large chest freezer; 2 water coolers; many fans but usually no more than 4 operating at the same time; and energy-saving lights consuming around 200W in total for 4-5 hours in the evenings; 12kW and 13kW shower heaters; rice cooker; 350w well-pump operating often; laundry washer, on cold water; plus very occasional or short duration use of air-compressor, welder, tractor battery-charger, 3hp pump, 2hp pump, vacuum cleaner, microwave oven, water heater for drinks, toaster, and electrical DIY tools. It all adds up.

[electau]

Electau, I agree but I have no reason to suspect that it is incorrect. Electricity theft is ruled out since my entire 1-mile+ long installation is very remote from anyone else. I’ve ruled out leakage by testing. I have 6 medium to large TV’s often on at the same time; 7 satellite decoders; PC; medium fridge-freezer; large chest freezer; 2 water coolers; many fans but usually no more than 4 operating at the same time; and energy-saving lights consuming around 200W in total for 4-5 hours in the evenings; 12kW and 13kW shower heaters; rice cooker; 350w well-pump operating often; laundry washer, on cold water; plus very occasional or short duration use of air-compressor, welder, tractor battery-charger, 3hp pump, 2hp pump, vacuum cleaner, microwave oven, water heater for drinks, toaster, and electrical DIY tools. It all adds up.

Yes, your load explains why your consumption is high per day, and that is without airconditioning.