Thai Electrical System

[dr_Pat_Pong]

A little knowledge is dangerous. No knowledge at all has to be worse

[Crossy]

A little knowledge is dangerous. No knowledge at all has to be worse

Oh so true ....

[lopburi3]

The toothbrush is probably BER (Beyond Economical Repair) chuck it and get a new one.

((cut))

So having said that, if you buy one of these in the States, make sure you buy extra AA batteries, as the Thai AA batteries have twice the voltage.....

<{POST_SNAPBACK}>

There are people here that may believe you.

[Thetyim]

Sbaker, the OP, has gone a bit quiet.

I wonder if he has been sticking his finger in the socket to check.

Are you still with us, sir ??

[dr_Pat_Pong]

The AA batteries electrocuted him

[JimGant]

There are people here that may believe you. biggrin.gif

You mean................?

[Crossy]

The toothbrush is probably BER (Beyond Economical Repair) chuck it and get a new one.

((cut))

So having said that, if you buy one of these in the States, make sure you buy extra AA batteries, as the Thai AA batteries have twice the voltage.....

There are people here that may believe you.

Just to really confuse the issue. The ARE 3V AA batteries.

They are actually 3V Lithium cells, used to be used in professional radio mikes. Cause enormous problem when some rock band install regular 1.5V AA's and wonder why the mike only works about 3 feet from the receiver. "Yes guv, we put all new batteries in, must be the other box"

It's really not fair to take the pxss out of some poor unfortunate who's fried his toothbrush and pick, some people do really ask for it though

BTW My 'pick' does not have batteries, just a long wooden handle and a steel point for smashing concrete

Edited June 15, 2005 by Crossy

[Greer]

BTW My 'pick' does not have batteries, just a long wooden handle and a steel point for smashing concrete

..yes, but the OPs "pick" was a "water pick"...while yours is only a water pick if you ignore the council pipework plans...

I have to agree with what one other poster said...never heard so much "white mans magic" misinformation before either...

To reiterate, Thailand mains supply is 220V 50Hz AC, while that in the USA is 110V 60Hz AC.

MEN stands for Main Earth Neutral - or at least it did when I went to school studying electrical technology. It is posible that it is used to mean other things in other places, but this is the current meaning in Australia.

A Residual Current Device (circuit breaker) or Earth Leakage breaker, also sometimes called a Core Balance Device measures the current in the Active (the lead that bites) against the current in the Neutral (the one that eventually, outside at the pole, is connected to earth), and if the balance is out by more than a certain amount (sometimes this is a user adjustment on the breaker) then the circuit breaker will trip and disconnect the power.

The assumption is that the circuit is out of balance because the current is flowing to earth via some fault - sometimes the fault is really some poor sod hanging off a faulty device, and the current is passing through him or her to ground, thus unbalancing the supply and return leg of the current sensing system.

A UPS has nothing whatsoever to do with the earthing situation - unless it has an isolation transformer in circuit which isolates both the neutral AND the active circuits from earth. If this is the case, then no current will leak to earth as the earth no longer forms part of the return path for the current, so if you are sitting there with bare feet, you cannot get a shock (or a tingle).

This, by the way, is a most unsafe situation, and you really should not set out to isolate the mains circuitry and supply under most domestic circumstances.

I have had all the power outlets in the home and office fited with 3-pin sockets and wired to a properly installed earth stake in the garden. No more tingles from various electrical devices and I now know the RCD will trip reliably in the event that someone accidentaly touches something they shouldn't.

My advice to the OP would be to get a step down transformer for those low wattage devices such as toothbrushes or other small appliances - if you really MUST keep using them.

It is actually much more satisfactory to simply pack away the 110V gear till you return to the USA, and in the meantime buy local or European 220V products or Australian 240V products.

[Boon Mee]

Thai power neutral is grounded just like "the western world".

Up here in this area the Neutral is not referenced to Earth in fact some of the Thais steal (or think their stealing it) power by opening up the Isolator and bridging a line then tying the other to an Earth stake. This gives them a floating supply of about 110 VAC --- enough to run flourecent lighting and will turn a fan. I installed Dual Pole CCT Breakers and Mains Isolation for this reason.

They are installing RCDs into some new homes up hear but no MEN (Mains Earth Neutral) link as we would normally see.

You must reside in a relatively new housing development.

Best bet is forget 110v equipment

Agreed

How many of you guys are actually Electricians??

Yep...there's only two kinds of Electricians out there - careful ones and dead ones...

[DaveYo]

Glory be!!!!!!!!!!!!!!!!!!!!!!!!!!! Without that step down transformer kiss your items zzzzzzzzzzzzzzzzzzzzzzzzzzzzz goodbye.

Stores that sell electronic speakers or units like receivers have them. Ask for the Siam Neoline Step down Transformers They have many kinds to suit your needs. Example you can get a 3,000 watt step down for under 3,000 Baht. A baht per watt as they say!!!!!

I have them here, and all works fine. Just fried out one of them recently cause I way overloaded it by using a fan from 1960!!!!!!!

Sigh

Daveyo

[DaveYo]

Oh by the way, Thailand homes use only 2 wire system, power and neutral. This means folks that the electrical system is NOT Grounded. Also be careful of their electrical meter boxes outside. Standard is only 5 AMPS. If you use 3 Air Cons all the same time, take a look at your meter and watch it spin like a flying saucer.

Get the 30 or 50 AMP Meter guys or you will have a spiffy fire right into the ceiling of your residence and you will see your lines melt right before your eyes. Installing these meters will give you a sigh of relief cause you will be forced to put in the 3-wire system or they won't bother at all putting in your spiffy meter. Now your system will be Grounded but check it - don't take their word on it.

For gods sakes don't be near water when you plug in your devices or you will be dancing the African Tango!!!!!!!!!!!!!!!!!

Also by the way, these 220 volt lines are pushing over 1 amp all by itself. More than enough to KILL you. Keep in mind--- the volts will not kill you, the AMPS will do it for you. You can have 10 volts or 5 volts but if you have over 1 amp it can definitly make your day cloudy for sure.

Daveyo

[chownah]

Oh by the way, Thailand homes use only 2 wire system, power and neutral.  This means folks that the electrical system is NOT Grounded.  Also be careful of their electrical meter boxes outside.  Standard is only 5 AMPS.  If you use 3 Air Cons all the same time, take a look at your meter and watch it spin like a flying saucer.

Get the 30 or 50 AMP Meter guys or you will have a spiffy fire right into the ceiling of your residence and you will see your lines melt right before your eyes.  Installing these meters will give you a sigh of relief cause you will be forced to put in the 3-wire system or they won't bother at all putting in your spiffy meter.  Now your system will be Grounded but check it - don't take their word on it.

For gods sakes don't be near water when you plug in your devices or you will be dancing the African Tango!!!!!!!!!!!!!!!!!

Also by the way, these 220 volt lines are pushing over 1 amp all by itself.  More than enough to KILL you.  Keep in mind--- the volts will not kill you, the AMPS will do it for you.  You can have 10 volts or 5 volts but if you have over 1 amp it can definitly make your day cloudy for sure. 

Daveyo

<{POST_SNAPBACK}>

In the north there are three options for meters offered for houses; 5, 15, and 30 amp. But you can actually draw more amps with each; the 5 amp can deliver 15 amps, the 15amp can deliver 50 amps, and the 30 amp can deliver 100amps.....don't ask me why but this is what they say at the electric company when you build a new house and you get your electrical service. I got the 30amp which delivers 100amps. It has two wires only. All of the other houses in my neighborhood have two wires only. One of the wires is 'hot', meaning that it has 220 volts on it....and the other one is 'ground'. The 'ground' wire is connected to the top wire on the electrical service pole...the pole out in the street. This top wire is bare...it has no insulation but it does have a wire connected to it that runs down the pole and into the ground....that is why I am 100% sure that it is a ground wire. So...you see...even two wire systems have a ground wire. Some of my electrical system is grounded; the electrical water heater has it and some of the outlets are three wire grounded just in case I should buy some appliance that requires it. These grounding circuits are connected to the ground wire that comes from the meter. The connection is made inside the breaker box. These grounding circuits also are connected to metal rods which are pounded into the ground...one for the water heater which is near the water heater and one for the breaker box which is located near the breaker box. I think when someone says that their service is 'grounded' they mean that some ground wire aside from the 'neutral' wire (remember, the neutral wire is in fact grounded at the electrical pole in the street) is run everywhere and then to a metal rod in the ground at your house.

Also I don't know what you mean when you say,"Also by the way, these 220 volt lines are pushing over 1 amp." Can you explain?

Also, some posts have indicated that in the US they have 110 volt mains supplying the houses. This is true but may mislead. In the US every house (that I've ever seen, but the US is really big so it may not be true everywhere) has 3 wires; two hot wires and one neutral. The neutral is grounded in the street and the grounding system connects to it in the breaker box, and two 110 volt lines that are 180 degrees out of phase. If an appliance is supplied with one hot line and the neutral then the result is 110 volts. If an appliance is supplied with both hot lines then the result is 220 volts. Also note that the electricity supplied is not exactly 110 volts but it is close enough.

[lopburi3]

1. The two wires from the electric meter are hot and neutral (it may look like a ground but it is called a neutral and in some cases could be hot). There is no ground running into your house from the electric pole. That neutral should be at ground potential but if not you can get zapped from it. You DO NOT connect this neutral to your ground connection in terminal box.

2. The electric meters are marked 5 (15A), 15 (45A) or 30 (90A). I have not seen a house will a 5 meter here in Bangkok for many years but for upcountry where homes do not have the need for more than fans and lights suspect it is still the normal service.

3. Neutral should be grounded but your home ground (three wire) is up to you. In all cases I would highly recommend RCCD/GFI protection in addition to a three wire system.

4. You do not require more than the 15 (45A) meter service for most homes. Remember that this is at 220 volts so the energy would be equal to about a 90 amp service in the US.

[chownah]

1.  The two wires from the electric meter are hot and neutral (it may look like a ground but it is called a neutral and in some cases could be hot).  There is no ground running into your house from the electric pole.  That neutral should be at ground potential but if not you can get zapped from it.  You DO NOT connect this neutral to your ground connection in terminal box.

2.  The electric meters are marked 5 (15A), 15 (45A) or 30 (90A).  I have not seen a house will a 5 meter here in Bangkok for many years but for upcountry where homes do not have the need for more than fans and lights suspect it is still the normal service.

3.  Neutral should be grounded but your home ground (three wire) is up to you.  In all cases I would highly recommend RCCD/GFI protection in addition to a three wire system.

4.  You do not require more than the 15 (45A) meter service for most homes.  Remember that this is at 220 volts so the energy would be equal to about a 90 amp service in the US.

<{POST_SNAPBACK}>

You are absolutely correct in saying to not connect the neutral to the ground connection!!! I was absolutely wrong to say to do this. Is there some way I can get the moderator to delete my last post? because I don't want dangerous informatoin to linger here on the forum since this will pose a danger for readers.

And by the way, my meter is rated 30(100) and I have a 100 amp main breaker. This was installed about 3 years ago. Is this some new type?

[lopburi3]

1.  The two wires from the electric meter are hot and neutral (it may look like a ground but it is called a neutral and in some cases could be hot).  There is no ground running into your house from the electric pole.  That neutral should be at ground potential but if not you can get zapped from it.  You DO NOT connect this neutral to your ground connection in terminal box.

2.  The electric meters are marked 5 (15A), 15 (45A) or 30 (90A).  I have not seen a house will a 5 meter here in Bangkok for many years but for upcountry where homes do not have the need for more than fans and lights suspect it is still the normal service.

3.  Neutral should be grounded but your home ground (three wire) is up to you.  In all cases I would highly recommend RCCD/GFI protection in addition to a three wire system.

4.  You do not require more than the 15 (45A) meter service for most homes.  Remember that this is at 220 volts so the energy would be equal to about a 90 amp service in the US.

<{POST_SNAPBACK}>

You are absolutely correct in saying to not connect the neutral to the ground connection!!! I was absolutely wrong to say to do this. Is there some way I can get the moderator to delete my last post? because I don't want dangerous informatoin to linger here on the forum since this will pose a danger for readers.

And by the way, my meter is rated 30(100) and I have a 100 amp main breaker. This was installed about 3 years ago. Is this some new type?

<{POST_SNAPBACK}>

[lopburi3]

I do know the 5 and 15 meters are always labeled three times (15-45) but have not looked at the 30 amp meter so can not be sure - everyone in my mooban has 15 amp service meters. That said we have a 50 amp main breaker on the 15/45 meter so believe there is leeway.

[aviador88]

Oh by the way, Thailand homes use only 2 wire system, power and neutral.  This means folks that the electrical system is NOT Grounded.  Also be careful of their electrical meter boxes outside.  Standard is only 5 AMPS.  If you use 3 Air Cons all the same time, take a look at your meter and watch it spin like a flying saucer.

Get the 30 or 50 AMP Meter guys or you will have a spiffy fire right into the ceiling of your residence and you will see your lines melt right before your eyes.  Installing these meters will give you a sigh of relief cause you will be forced to put in the 3-wire system or they won't bother at all putting in your spiffy meter.  Now your system will be Grounded but check it - don't take their word on it.

For gods sakes don't be near water when you plug in your devices or you will be dancing the African Tango!!!!!!!!!!!!!!!!!

Also by the way, these 220 volt lines are pushing over 1 amp all by itself.  More than enough to KILL you.  Keep in mind--- the volts will not kill you, the AMPS will do it for you.  You can have 10 volts or 5 volts but if you have over 1 amp it can definitly make your day cloudy for sure. 

Daveyo

<{POST_SNAPBACK}>

Keep in mind--- the volts will not kill you, the AMPS will do it for you.  You can have 10 volts or 5 volts but if you have over 1 amp it can definitly make your day cloudy for sure

Not quite correct, IMHO.

An electric welder will have a voltage potential at the output side of about 50 V and anywhere between 200 and 500 Amperes. Tickles a little and no more.

A static discharge on a dry day, touching a doorknob or sliding across the car seat touching the handle can be a million volts but very little current. Annoying, but definitely not deadly. (except to electronic micro circuitry)

It is the combination of voltage and current that kills.

Back in school, we used to take a 1,5 volt flashlight battery, hooked up to the ignition coil of an automobile and dared the teacher to touch it. Well, he did "once" and never again. But we kids had fun sticking the wires onto other students bare arms or legs. Quite a shock, about 35,000 volts but by this time just milli amps, but still not deadly.

[Greer]

Also, some posts have indicated that in the US they have 110 volt mains supplying the houses. This is true but may mislead. In the US every house (that I've ever seen, but the US is really big so it may not be true everywhere) has 3 wires; two hot wires and one neutral. The neutral is grounded in the street and the grounding system connects to it in the breaker box, and two 110 volt lines that are 180 degrees out of phase. If an appliance is supplied with one hot line and the neutral then the result is 110 volts. If an appliance is supplied with both hot lines then the result is 220 volts. Also note that the electricity supplied is not exactly 110 volts but it is close enough.

I suspect that your mention of the three wires and the 220V in the US may really be referring to a multiphase supply.

The mains supply on the street in every country will usually have four wires: three different "actives" known as phases, and a neutral.

The Earth ("Ground" if you prefer) is provided in the house by installing a ground spike usually just outside the wall of the house at some convenient location.

As Lopburi says, the Neutral is also grounded out on the street, so you must not connect it to the ground in the house distribution board.

The three actives are 120 degrees out of phase with each other (3 x 120 = 360 degrees).

In a 220 Volt system as used in Thailand, the 220 volts refers to the voltage between ANY ONE of the Active phases and the Neutral.

The voltage between ANY TWO of the Active Phases will be approximately 318V.

Three phase supply will usually be provided in commercial premises, but not normally in the home, however they do sometimes provide two of the three phases to domestic premises, depending on balancing the load across the three phases along the street, and of course dependent upon the load requirements of the premises itself.

In countries with 110V phase to neutral domestic mains supply, the phase to phase voltage is around 190V.

The correct way to provide an earthed and safe system in your home is to have an electrician (yes - you CAN find real electricians...eventually...) install a proper earth spike outside in the garden. The power outlets and fluorescent light fittings etc are then earthed to this earth spike.

By the way, fitting a higher current meter will not provide a higher current supply to the house. You will have to get the local supply authority to increase the size of the "pole-top" fuse outside on the pole top (obviously!) but they will only do this once they have inspected the house cabling etc to ensure it is safe and that the consumer mains (the cables between the power meter out in the street and the switchboard in your house) are large enough to carry the increased load current that you wish to draw from the supply.

Regarding being shocked or electrocuted - yes, the voltage/current combination is what will get you - just because a circuit CAN supply a huge amount of current doesn't mean it will shock you - it depends on the supply voltage and your body resistance. A 5 volt supply is virtually guaranteed not to have any effect on the average human because the current forced through his or her body by a 5V "pressure" (voltage) will be negligible.

The calculation is based on Ohms Law and works as below:

Current (I in Amps) equals the Voltage (V in Volts) divided by the Resistance (R in Ohms)

As a realistic figure for the skin resistance of a human is often something more than 100,000 ohms, a 5 volt supply across that resistance will result in a current of 50 micro-amps flowing through the victims skin or body.

It is usually accepted that a current of around 21 milliamps is likely to be lethal.

A 220 Volt supply across that same 100,000 ohms skin resistance will force a current of 2.2 milliamps into the victim and result in a definite shock.

Now the nasty bit - THE ABOVE IS AN EXAMPLE TO ILLUSTRATE THE CALCULATION ONLY - Human body resistance varies widely between different people, on different days, depending on temperature, humidity, and a number of other factors, it can also change rapidly once a small current starts to flow - people HAVE been killed by electrocution on as little as a 32 volt supply, so don't go around assuming that you can touch any mains supply with impunity.

You WILL get a shock, and it COULD kill you.

Do get an earth fitted at your home, and also get an earth leakage circuit breaker or Residual Current Device type breaker fitted to protect you and your family - you can buy them, and they save lives - it's worth it.

Be safe!

[lopburi3]

The correct way to provide an earthed and safe system in your home is to have an electrician (yes - you CAN find real electricians...eventually...) install a proper earth spike outside in the garden. The power outlets and fluorescent light fittings etc are then earthed to this earth spike.

To prevent confusion believe this should read visa the ground bus of your breaker panel.

[Pink Mist]

BTW My 'pick' does not have batteries, just a long wooden handle and a steel point for smashing concrete

..yes, but the OPs "pick" was a "water pick"...while yours is only a water pick if you ignore the council pipework plans...

I have to agree with what one other poster said...never heard so much "white mans magic" misinformation before either...

To reiterate, Thailand mains supply is 220V 50Hz AC, while that in the USA is 110V 60Hz AC.

MEN stands for Main Earth Neutral - or at least it did when I went to school studying electrical technology. It is posible that it is used to mean other things in other places, but this is the current meaning in Australia.

A Residual Current Device (circuit breaker) or Earth Leakage breaker, also sometimes called a Core Balance Device measures the current in the Active (the lead that bites) against the current in the Neutral (the one that eventually, outside at the pole, is connected to earth), and if the balance is out by more than a certain amount (sometimes this is a user adjustment on the breaker) then the circuit breaker will trip and disconnect the power.

The assumption is that the circuit is out of balance because the current is flowing to earth via some fault - sometimes the fault is really some poor sod hanging off a faulty device, and the current is passing through him or her to ground, thus unbalancing the supply and return leg of the current sensing system.

A UPS has nothing whatsoever to do with the earthing situation - unless it has an isolation transformer in circuit which isolates both the neutral AND the active circuits from earth. If this is the case, then no current will leak to earth as the earth no longer forms part of the return path for the current, so if you are sitting there with bare feet, you cannot get a shock (or a tingle).

This, by the way, is a most unsafe situation, and you really should not set out to isolate the mains circuitry and supply under most domestic circumstances.

I have had all the power outlets in the home and office fited with 3-pin sockets and wired to a properly installed earth stake in the garden. No more tingles from various electrical devices and I now know the RCD will trip reliably in the event that someone accidentaly touches something they shouldn't.

My advice to the OP would be to get a step down transformer for those low wattage devices such as toothbrushes or other small appliances - if you really MUST keep using them.

It is actually much more satisfactory to simply pack away the 110V gear till you return to the USA, and in the meantime buy local or European 220V products or Australian 240V products.

<{POST_SNAPBACK}>

It doesn't stand for "Main" it stands for "Multiple" don't know how many times I have to repeat myself, check the definitions section in "ASNZ3000"

[dr_Pat_Pong]

Shocking

[chownah]

Also, some posts have indicated that in the US they have 110 volt mains supplying the houses. This is true but may mislead. In the US every house (that I've ever seen, but the US is really big so it may not be true everywhere) has 3 wires; two hot wires and one neutral. The neutral is grounded in the street and the grounding system connects to it in the breaker box, and two 110 volt lines that are 180 degrees out of phase. If an appliance is supplied with one hot line and the neutral then the result is 110 volts. If an appliance is supplied with both hot lines then the result is 220 volts. Also note that the electricity supplied is not exactly 110 volts but it is close enough.

I suspect that your mention of the three wires and the 220V in the US may really be referring to a multiphase supply.

....................................

<{POST_SNAPBACK}>

I was not talking about a multiphase system.....the way I described it is the way it is. I replaced the main panel in my house myself...with no help from anyone. It passed inspection first try....perfect! However I believe I mis-spoke above. I don't think that the grounding system connects to the neutral supply wire. I checked my Thai house's main panel and the two systems are seperate and NOT connected. I'm kind of embarrassed that I would post this error....I guess my memory isn't what it used to be.......but......the house DEFINITELY has three supply wires and DEFINITELY two are 110 volts and one is neutral....and DEFINITELY the voltage measured from one hot to the other hot is 220 volts.....not exactly 220 volts but close enough....actually different supply systems provide slightly different voltages. Some of the outlets are run off of one of the hot wires and some are run off of the other hot wire. The electric stove runs off of the two hot wires and the neutral.

In the US a split phase system has 4 wires....I never go there.

Edited June 17, 2005 by chownah

[lopburi3]

Also, some posts have indicated that in the US they have 110 volt mains supplying the houses. This is true but may mislead. In the US every house (that I've ever seen, but the US is really big so it may not be true everywhere) has 3 wires; two hot wires and one neutral. The neutral is grounded in the street and the grounding system connects to it in the breaker box, and two 110 volt lines that are 180 degrees out of phase. If an appliance is supplied with one hot line and the neutral then the result is 110 volts. If an appliance is supplied with both hot lines then the result is 220 volts. Also note that the electricity supplied is not exactly 110 volts but it is close enough.

I suspect that your mention of the three wires and the 220V in the US may really be referring to a multiphase supply.

....................................

<{POST_SNAPBACK}>

I was not talking about a multiphase system.....the way I described it is the way it is. I replaced the main panel in my house myself...with no help from anyone. It passed inspection first try....perfect! However I believe I mis-spoke above. I don't think that the grounding system connects to the neutral supply wire. I checked my Thai house's main panel and the two systems are seperate and NOT connected. I'm kind of embarrassed that I would post this error....I guess my memory isn't what it used to be.......but......the house DEFINITELY has three supply wires and DEFINITELY two are 110 volts and one is neutral....and DEFINITELY the voltage measured from one hot to the other hot is 220 volts.....not exactly 220 volts but close enough....actually different supply systems provide slightly different voltages. Some of the outlets are run off of one of the hot wires and some are run off of the other hot wire. The electric stove runs off of the two hot wires and the neutral.

In the US a split phase system has 4 wires....I never go there.

<{POST_SNAPBACK}>

Actually the US normally uses 117 or 120 volt supply and the two phase are out 120 degrees (think 360 and 3 phase - each 120). When you use the two hot the total voltage is 208 and that is used for electric stoves and such.

Edited June 17, 2005 by lopburi3

[chownah]

Also, some posts have indicated that in the US they have 110 volt mains supplying the houses. This is true but may mislead. In the US every house (that I've ever seen, but the US is really big so it may not be true everywhere) has 3 wires; two hot wires and one neutral. The neutral is grounded in the street and the grounding system connects to it in the breaker box, and two 110 volt lines that are 180 degrees out of phase. If an appliance is supplied with one hot line and the neutral then the result is 110 volts. If an appliance is supplied with both hot lines then the result is 220 volts. Also note that the electricity supplied is not exactly 110 volts but it is close enough.

I suspect that your mention of the three wires and the 220V in the US may really be referring to a multiphase supply.

....................................

<{POST_SNAPBACK}>

I was not talking about a multiphase system.....the way I described it is the way it is. I replaced the main panel in my house myself...with no help from anyone. It passed inspection first try....perfect! However I believe I mis-spoke above. I don't think that the grounding system connects to the neutral supply wire. I checked my Thai house's main panel and the two systems are seperate and NOT connected. I'm kind of embarrassed that I would post this error....I guess my memory isn't what it used to be.......but......the house DEFINITELY has three supply wires and DEFINITELY two are 110 volts and one is neutral....and DEFINITELY the voltage measured from one hot to the other hot is 220 volts.....not exactly 220 volts but close enough....actually different supply systems provide slightly different voltages. Some of the outlets are run off of one of the hot wires and some are run off of the other hot wire. The electric stove runs off of the two hot wires and the neutral.

In the US a split phase system has 4 wires....I never go there.

<{POST_SNAPBACK}>

Actually the US normally uses 117 or 120 volt supply and the two phase are out 120 degrees (think 360 and 3 phase - each 120). When you use the two hot the total voltage is 208 and that is used for electric stoves and such.

<{POST_SNAPBACK}>

Actually I think you are wrong. I think the two hot lines are 180 degress out of phase. I think that in multi phase systems you count the phase angle as the angle between the hot wires and the neutral doesn't come into play...since the US has two hot wires there is only one phase angle, the one between the two hot wires...and so it is incorrect to talk about multi phase because multi mean more than one and in the US you've only got one phase angle......but since you disagree I think I'll go out on to the internet and see if I can find out what others think.

[lopburi3]

Also, some posts have indicated that in the US they have 110 volt mains supplying the houses. This is true but may mislead. In the US every house (that I've ever seen, but the US is really big so it may not be true everywhere) has 3 wires; two hot wires and one neutral. The neutral is grounded in the street and the grounding system connects to it in the breaker box, and two 110 volt lines that are 180 degrees out of phase. If an appliance is supplied with one hot line and the neutral then the result is 110 volts. If an appliance is supplied with both hot lines then the result is 220 volts. Also note that the electricity supplied is not exactly 110 volts but it is close enough.

I suspect that your mention of the three wires and the 220V in the US may really be referring to a multiphase supply.

....................................

<{POST_SNAPBACK}>

I was not talking about a multiphase system.....the way I described it is the way it is. I replaced the main panel in my house myself...with no help from anyone. It passed inspection first try....perfect! However I believe I mis-spoke above. I don't think that the grounding system connects to the neutral supply wire. I checked my Thai house's main panel and the two systems are seperate and NOT connected. I'm kind of embarrassed that I would post this error....I guess my memory isn't what it used to be.......but......the house DEFINITELY has three supply wires and DEFINITELY two are 110 volts and one is neutral....and DEFINITELY the voltage measured from one hot to the other hot is 220 volts.....not exactly 220 volts but close enough....actually different supply systems provide slightly different voltages. Some of the outlets are run off of one of the hot wires and some are run off of the other hot wire. The electric stove runs off of the two hot wires and the neutral.

In the US a split phase system has 4 wires....I never go there.

<{POST_SNAPBACK}>

Actually the US normally uses 117 or 120 volt supply and the two phase are out 120 degrees (think 360 and 3 phase - each 120). When you use the two hot the total voltage is 208 and that is used for electric stoves and such.

<{POST_SNAPBACK}>

Actually I think you are wrong. I think the two hot lines are 180 degress out of phase. I think that in multi phase systems you count the phase angle as the angle between the hot wires and the neutral doesn't come into play...since the US has two hot wires there is only one phase angle, the one between the two hot wires...and so it is incorrect to talk about multi phase because multi mean more than one and in the US you've only got one phase angle......but since you disagree I think I'll go out on to the internet and see if I can find out what others think.

<{POST_SNAPBACK}>

I will make it easy for you. http://www.nationmaster.com/encyclopedia/T...-electric-power

[chownah]

Also, some posts have indicated that in the US they have 110 volt mains supplying the houses. This is true but may mislead. In the US every house (that I've ever seen, but the US is really big so it may not be true everywhere) has 3 wires; two hot wires and one neutral. The neutral is grounded in the street and the grounding system connects to it in the breaker box, and two 110 volt lines that are 180 degrees out of phase. If an appliance is supplied with one hot line and the neutral then the result is 110 volts. If an appliance is supplied with both hot lines then the result is 220 volts. Also note that the electricity supplied is not exactly 110 volts but it is close enough.

I suspect that your mention of the three wires and the 220V in the US may really be referring to a multiphase supply.

....................................

<{POST_SNAPBACK}>

I was not talking about a multiphase system.....the way I described it is the way it is. I replaced the main panel in my house myself...with no help from anyone. It passed inspection first try....perfect! However I believe I mis-spoke above. I don't think that the grounding system connects to the neutral supply wire. I checked my Thai house's main panel and the two systems are seperate and NOT connected. I'm kind of embarrassed that I would post this error....I guess my memory isn't what it used to be.......but......the house DEFINITELY has three supply wires and DEFINITELY two are 110 volts and one is neutral....and DEFINITELY the voltage measured from one hot to the other hot is 220 volts.....not exactly 220 volts but close enough....actually different supply systems provide slightly different voltages. Some of the outlets are run off of one of the hot wires and some are run off of the other hot wire. The electric stove runs off of the two hot wires and the neutral.

In the US a split phase system has 4 wires....I never go there.

<{POST_SNAPBACK}>

Actually the US normally uses 117 or 120 volt supply and the two phase are out 120 degrees (think 360 and 3 phase - each 120). When you use the two hot the total voltage is 208 and that is used for electric stoves and such.

<{POST_SNAPBACK}>

Actually I think you are wrong. I think the two hot lines are 180 degress out of phase. I think that in multi phase systems you count the phase angle as the angle between the hot wires and the neutral doesn't come into play...since the US has two hot wires there is only one phase angle, the one between the two hot wires...and so it is incorrect to talk about multi phase because multi mean more than one and in the US you've only got one phase angle......but since you disagree I think I'll go out on to the internet and see if I can find out what others think.

<{POST_SNAPBACK}>

I will make it easy for you. http://www.nationmaster.com/encyclopedia/T...-electric-power

<{POST_SNAPBACK}>

Great, I'll check it out. Here's what I found at wikipedia:

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A transformer connected to a 3-wire distribution system has a single phase input (primary) winding. The output (secondary) winding is centre-tapped with a conductor called the neutral on the centre tap, which is normally connected to earth ground. Split phase is most common in countries with a standard phase-neutral voltage of 120V (or thereabouts). in this case, the transformer is rated 120 volts on either side of the centre tap, giving 240 volts between the two ungrounded terminals.

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It doesn't say that this is what the USA has but I think that this is so. Also there seems to be some difference of opinion about what 'split phase' means. My opinion is that split phase originally refered to something different but that the term is now not uncommonly used to describe the above.....but then maybe the definition of split phase that I learned is wrong...don't really know....anyway I'm off to check out the link.....

Cool, I got out and back in time to edit....the link appears to me to be a good description of 3 phase...which uses 4 wires....just like in the USA. The link also says at the bottom, " Most domestic loads are single phase. Generally three phase power either doesn't enter homes at all or where it does it is split out at the main distribution board." I maintain that in the USA the typical service is the single phase. I used to be a candle maker and checked into getting 3 phase power to melt wax...thinking I would save money (probably wouldn't)....and I found out that it costs a fortune to get 3 phase installed...can't remember how much but I'll make a wild guess of over $2000 dollars...and it can only be done this cheaply if the 3 phase is already to the pole in front of your property...you have to pay extra if you have to bring it to your property.

Edited June 17, 2005 by chownah

[Deinnun]

It's different in different countries.

This is how it is in Sweden:

Houses are fed with 3-phase 3x400V (230V between a phase and neutral). Phases are split in the breaker box and distributed evenly within the house. Appliances using 2 or 3 phases are common.

Apartments are fed either single phase 230V or two of the three phases.

The grounding system is quite unique, it is forbidden to have your own ground spike. Instead, the neutral is well grounded at the transformer you are fed from. The breaker box has 5 buses, 3 phases, neutral and ground. The neutral and ground are connected in a single point in the breaker box, thus the grounding relies on the neutral grounding at the transformer. This system works well and the potential on the ground wires are rarely more than a few volts even with severe imbalance between the phases. Appliances relying on neutral being at ground potential are forbidden.

You can have a 5 wire feed if you wish, the neutral and ground are connected at the transformer instead.

The primary of the transformers are usually connected in triangle configuration with no neutral while the secondaries are in star configuration. We use large transformers, here in my area one huge transformer serves 93 houses, each with 3x20A.

I believe there are 3 different systems in US. One where a transformer primary is fed from 2 of the 3 phases and with a 240V centertapped secondary, center tap usually grounded. One where 2 phases are used with 120V hot to neutral and 208V between the two hots. Lastly one with single phase 120V.

Single phase 220V seems to be the norm in Thailand with an unreliable neutral where you don't know how well it is grounded. Connecting the neutral with your own ground spike would not be recommended here. Appliances relying on the neutral being at ground potential should not be used.

Just my 2 of any currency

[cobra]

Hard to believe this is a serious Post but I will answer anyway!

The Thai electrical system is 220 / 240 VAC, the US is 110 VAC.

.. and 50 cycle, which affects time keeping and motor heating ...

FYI: http://users.pandora.be/worldstandards/electricity.htm

[lopburi3]

Wife turned the lights out so was not able to send this until now. See where the US does have what they call a splitphase system which is fed by a single phase of the normal three phase high voltage lines to the primary and the secondary is a center tap of the 240 volt transformer and use this to feed some residential areas so you end up with two 120 volt legs and 240 end to end. Guess being overseas 40 years erases the memory as I never recall anything but 208 volts for home use. Sorry for (my) confusion. Can see why most homes in US are sold with appliances as they have to be wired for either 208 or 240 depending on where used.

At least I learned something. Thanks.

[chownah]

Wife turned the lights out so was not able to send this until now.  See where the US does have what they call a splitphase system which is fed by a single phase of the normal three phase high voltage lines to the primary and the secondary is a center tap of the 240 volt transformer and use this to feed some residential areas so you end up with two 120 volt legs and 240 end to end.  Guess being overseas 40 years erases the memory as I never recall anything but 208 volts for home use.  Sorry for (my) confusion.  Can see why most homes in US are sold with appliances as they have to be wired for either 208 or 240 depending on where used.

At least I learned something.  Thanks.

<{POST_SNAPBACK}>

I don't know what the electricity was 40 years ago but now I think that almost everyone if not everyone has 240 volts at least on the west coast which is the only place where I have experience. When purchasing appliances which use 240 no one even considers if it s 240 or 208 volts. I vaguely remember that many years ago that people in rural places had a different electrical system. Did you live on a farm?