Single To 3 Phase

[offset]

After having a problem with low voltage the PEA have offered to change my single phase supply to 3 phase and I was wondering how much it would cost to change the house wiring to suit 3 phase

[gotlost]

House wiring should not need to be upgraded but your service panel will need to be changed over for 3 Phase. This cost plus labor.

[shadiadi]

Cost me about 30,000 to upgrade my meter and about another 20,000 to upgrade my main breaker box but tht was Phuket so the 20,000 might be cheaper in other provinces. Unless you have some heavy duty machinery requiring 3 phase motors 2 phase should suffice.

If you are using 3 phase machinery in your house I would advise rewiring standard wiring will get to hot and start a fire To rewire my place cost an extra 15,000 on top of what is mentioned above.

Edited May 26, 2010 by shadiadi

[gotlost]

Cost me about 30,000 to upgrade my meter and about another 20,000 to upgrade my main breaker box but tht was Phuket so the 20,000 might be cheaper in other provinces. Unless you have some heavy duty machinery requiring 3 phase motors 2 phase should suffice.

The cost is OK but I tend to thank that if you are having low voltage on single phase you'll also have it on 3 phase.

[shadiadi]

There is no need to rewire the whole house only the wiring to the sockets that use 3 phase machinery. No domestic appliances I know of require 3 phase maybe 2 phase. I know 1 phase isn't good for some shower units just probably need to phase and some bigger breaker fuses like 50amp+

[offset]

Thanks for the replies so far I have been through the low voltage in an earlier thread when the PEA came to check out the problem with everything on not including the water pump which is about 10 amp the supply voltage drooped from 215v to 157v it was the PEA that suggested that 3 phase would solve the problem I would guess that 3 phase is an industrial supply and there would be a better control on supply voltage

[PhilHarries]

No domestic appliances I know of require 3 phase maybe 2 phase.

No.

Three phase systems, with a single center-tapped transformer giving two live conductors, is a common distribution scheme for residential and small commercial buildings in North America. This arrangement is sometimes incorrectly referred to as "two phase". A similar method is used for a different reason on construction sites in the UK. Small power tools and lighting are supposed to be supplied by a local center-tapped transformer with a voltage of 55 V between each power conductor and earth. This significantly reduces the risk of electric shock in the event that one of the live conductors becomes exposed through an equipment fault whilst still allowing a reasonable voltage of 110 V between the two conductors for running the tools.

[InterestedObserver]

It's all about distance from the supply transformer, wire material and size, and load per phase. With a 3-phase supply the individual single phase household loads can be evenly divided among the three phases resulting in a lower overall voltage drop. The house distribution panel and main breaker will need to be changed along with the meter.

[stgrhe]

It's all about distance from the supply transformer, wire material and size, and load per phase. With a 3-phase supply the individual single phase household loads can be evenly divided among the three phases resulting in a lower overall voltage drop. The house distribution panel and main breaker will need to be changed along with the meter.

That is true, but it will be very difficult, if not impossible, to balance the load over the three phases without a complete circuit redesign. Having said that, if the OP can live with an unbalanced distribution fine.

[kamalabob2]

I have a suggestion for the O.P. He should consider going in person with a good translator to the office of the P.E.A. and have an engineer of the P.E.A. put in writing what they are suggesting. It should cost nothing for an engineer and supervisor of the P.E.A. to come to your property, perform some tests and look at what equipment in terms of a breaker box you already have installed. They MIGHT be suggesting you buy your own 3 phase transformer. Our home has no 3 phase appliances, no 3 phase a/c units, but a reputable electrical contractor installed a 3 phase transformer (which actually has a host of associated equipment installed) near our PEA electrical meter. This was for a new home building project with quite a few a/c units, ceiling lights and many grounded electrical sockets installed.

If the P.E.A. technical staff put what they think you need in WRITING, they can also give you a price bid for the items OUTSIDE your home the P.E.A. often instlales. You can also obtain a written bid from a reputable electrical contractor for the same items perhaps at a lower cost. You still would pay some "service upgrade refundable deposits on your new P.E.A. meter" directly to the P.E.A. if you use a private contractor or the P.E.A. Many "meter and new service" fees are posted on the wall of your local P.E.A. office. The headquarters of the P.E.A. in Bangkok has staff you can phone who UNDERSTAND and speak English for further clarification or to confirm a price quote from your local P.E.A.

Good luck.

[InterestedObserver]

It's all about distance from the supply transformer, wire material and size, and load per phase. With a 3-phase supply the individual single phase household loads can be evenly divided among the three phases resulting in a lower overall voltage drop. The house distribution panel and main breaker will need to be changed along with the meter.

That is true, but it will be very difficult, if not impossible, to balance the load over the three phases without a complete circuit redesign. Having said that, if the OP can live with an unbalanced distribution fine.

What the OP can't live with is the 157 volts, and that was without his 10 amp water pump running.

[offset]

I have a suggestion for the O.P. He should consider going in person with a good translator to the office of the P.E.A. and have an engineer of the P.E.A. put in writing what they are suggesting. It should cost nothing for an engineer and supervisor of the P.E.A. to come to your property, perform some tests and look at what equipment in terms of a breaker box you already have installed. They MIGHT be suggesting you buy your own 3 phase transformer. Our home has no 3 phase appliances, no 3 phase a/c units, but a reputable electrical contractor installed a 3 phase transformer (which actually has a host of associated equipment installed) near our PEA electrical meter. This was for a new home building project with quite a few a/c units, ceiling lights and many grounded electrical sockets installed.

If the P.E.A. technical staff put what they think you need in WRITING, they can also give you a price bid for the items OUTSIDE your home the P.E.A. often instlales. You can also obtain a written bid from a reputable electrical contractor for the same items perhaps at a lower cost. You still would pay some "service upgrade refundable deposits on your new P.E.A. meter" directly to the P.E.A. if you use a private contractor or the P.E.A. Many "meter and new service" fees are posted on the wall of your local P.E.A. office. The headquarters of the P.E.A. in Bangkok has staff you can phone who UNDERSTAND and speak English for further clarification or to confirm a price quote from your local P.E.A.

Good luck.

I have already had the main manager to my house and have a letter and a quote the problem is that the letter is in Thai and although my lady speaks fairly good English she find it difficult to translate the technical details

[InterestedObserver]

They MIGHT be suggesting you buy your own 3 phase transformer.

Then it may be better (cheaper) to buy a single phase transformer, set on your property, and avoid rewiring the house. The problem is the distribution system, a properly sized transformer will easily support a 2-3% voltage drop at the transformer. This assumes that the 25kv primary system is up to the task.

Edited May 28, 2010 by InterestedObserver

[Forkinhades]

It is quite easy to divide your house into 3 phases, just try to balance as best you can. If you tell here what you have, I am sure somebody will give you answer as to where you put each circuit (on what phase). You do need to balance the 3 phases, as you will have a neutral, which will in effect offload any inbalance. You only need to fully balance when you do NOT have a neutral.