Electric Wiring

[ianpants69]

Hello all,

perhaps someone can help ....

I am fitting a water heater and the condo already has the wiring and fuse installed for it so i just have to connect it.

I have two white wires and one black... am I safe to assume that the white wire is earth as they don't seem to differentiate between live and neutral?

This is not the green/blue/brown I am familiar with... can anyone help?

[slimdog]

Water heaters can be very dangerous if wired up wrong. DONT ASSUME ANYTHING. If you are not 100% sure get an electrician to install or at least verify the wiring before you switch on.

Ideally water heaters should run through a elcb (earth leakage circuit breaker), and ground to earth.

[lopburi3]

It is not safe to assume anything as you should have a green ground wire in any color code. Probably one of the white wires is ground but I would not bet on it. Have a good electrician take care of it. You could trace back to fuse (breaker?) and meter it out but cheaper and safer to have someone else do it. Whatever you find make sure they put a real ground on it. And if it is a wall type heater it should have an elcb built in so be sure to check it every few weeks.

[Jockstar]

In OZ and NZ. White can be live. I think also here in LOs. Tell me is it a 240v water heater or 415v? Dont asume anything is earth in LOS. They dont seem to use an earth very often. My guess(i'm an electrician) is that its a 415v water heater.. Usually you have 3 phases( UK red, yellow blue) (Oz Red, white blue) but to get 415v you really only need 2 phases. Hence why the the 2 whites might be your supply. The black is your neutral. One way to find out is. Seperate the wires and make sure they touch nothing. Get a volt tester pen.cheap here. Put the power on and touch the pen to the stripped core. If it lights then it is live. But i am an electrician and for me this is easy to figure out. If in doubt get someone who knows what they are doing. If your heater you are installing is 240v then just connect the spare white into a connector block and tape it up. Connect the last 2 cores white/live black/neutral. Hope this helps. If you need anymore info then just shout

[andy50]

hi jockstar, here in the uk the colours have recently changed! instead of red yellow blue , its now black grey and brown for 3 phase . confusing or what!!

[Jockstar]

hi jockstar, here in the uk the colours have recently changed! instead of red yellow blue , its now black grey and brown for 3 phase . confusing or what!!

Since when?

[Firefoxx]

Get the condo manager/engineer/fixitguy to take a look. Or...

If you don't have a multimeter, find any small appliance, like a desk fan, have it switched on and unplugged, and touch two wires at a time to its wall prongs. That way you'll find out which one is line and neutral. It's quick and dirty, but it gets the job done. Just be careful not to touch the wires together (or to touch them).

I don't think a condo would have a 3 phase line.

[paulfr]

Get the condo manager/engineer/fixitguy to take a look.  Or...

If you don't have a multimeter, find any small appliance, like a desk fan, have it switched on and unplugged, and touch two wires at a time to its wall prongs.  That way you'll find out which one is line and neutral.  It's quick and dirty, but it gets the job done.  Just be careful not to touch the wires together (or to touch them).

I don't think a condo would have a 3 phase line.

<{POST_SNAPBACK}>

Be careful here with this test !!

If the appliance is 220v and the feed is 415v, even a short duration could short out the windings as I doubt they are overdesigned to handle 2x voltage.

[[You can put a resisitor in series but it would need to be about R= [ (415-220)/current to heater ] in value. Too much of a nuisance to deal with.]]

Get a pro to help you.

[billd766]

Hello all,

perhaps someone can help ....

I am fitting a water heater and the condo already has the wiring and fuse installed for it so i just have to connect it.

I have two white wires and one black... am I safe to assume that the white wire is earth as they don't seem to differentiate between live and neutral?

This is not the green/blue/brown I am familiar with... can anyone help?

<{POST_SNAPBACK}>

If you don't know or you are not sure

DON'T THINK ABOUT INSTALLING IT!!!!!!!

You can get somebody to do it for a low price (is your life worth only 500 baht or less?)

as that is what you will pay and even if it is 1,000 baht do it the safe way.

[Pink Mist]

soapdodgers are so bland, red white and blue would be their colours of choice i would have thought.

The white wire in Oz is usually the switched wire Jockstar

[Jockstar]

soapdodgers are so bland, red white and blue would be their colours of choice i would have thought.

The white wire in Oz is usually the switched wire Jockstar

Which is live?If switched. Are you an electrician bronco? If you have a 415v supply. You will find that its blue, white and red.(in OZ) So white is LIVE. To the Op, any joy mate. Post back.

[Crossy]

I'm with the others in saying 'if you don't know how to find the live wire don't connect anything'.

Get your condo. odd-job to do it. It is not worth risking getting fried.

[Crossy]

hi jockstar, here in the uk the colours have recently changed! instead of red yellow blue , its now black grey and brown for 3 phase . confusing or what!!

Since when?

Since July last year

Look here:

http://www.gravitystorm.co.uk/shine/archiv...-cable-colours/

[Gary A]

It's not at all likely that you will find three phase wiring here in Thailand except in a factory. They usually use a black wire that is the hot one and the white is the neutral. 95% of the time you will not have a ground wire. In the case of a hot-water shower heater the ground is normally required to make the built in ground fault work. That will usually be another white wire. What makes it interesting is that this is not always the case. You will need a simple screw driver tester with the little light in it. The hot wire will glow bright and sometimes the common will also give a light but it will be dim. The ground wire will be totally dead. TIT!

Edited March 29, 2005 by Gary A

[lopburi3]

GFI/ELCB never needs a ground wire to operate. It does not reference or use ground period. It works on a difference between neutral and hot wires.

A shower needs a ground wire for the same reason anything that may become hot needs it - there is electric prior to the built in ELCB that if shorted to the case you want to lead directly to ground and thus blow the breaker before you touch it. It should be a green wire here. And for further safety I would advise another ELCB upstream.

You should not see any voltage on a neutral wire (light bulb on tester) if the neutral is properly grounded at entrance panel. Of course this is often not done here but to see it on a normal testers would take really good eyesight (even the hot is often hard to see in bright light).

[andy50]

hi jockstar, here in the uk the colours have recently changed! instead of red yellow blue , its now black grey and brown for 3 phase . confusing or what!!

<{POST_SNAPBACK}>

Since when?

<{POST_SNAPBACK}>

hi jockstar my computers been down,so im late repying,the new colours came into use last year about decembertime,its meant to match the colours in europe

even the pvc insulation that the cables use are now toxic free and non-flammable!

[Gary A]

I was getting shocked off my computer case. I reversed the plug thus changed the polarity and still get a light with my cheap little screwdriver tester when I touch the case. I was told the white common was SUPPOSED to be grounded at the pole. Obviously mine is NOT. The point being is that if you are in any position to do it you should make sure you have a separate ground. It's interesting that the ground wire I insisted on for my shower is red. LOL!

[Crossy]

I was getting shocked off my computer case. I reversed the plug thus changed the polarity and still get a light with my cheap little screwdriver tester when I touch the case. I was told the white common was SUPPOSED to be grounded at the pole. Obviously mine is NOT. The point being is that if you are in any position to do it you should make sure you have a separate ground. It's interesting that the ground wire I insisted on for my shower is red. LOL!

The reason you are getting a tickle off the computer case is not that the polarity is wrong or that the neutral is not grounded (actually an ungrounded neutral will mean you DON'T get a shock). Computers all have a mains inlet filter, these MUST be correctly grounded or the case will float at around 115 volts, not going to be lethal but rather unpleasant. Check the ground in your wall socket and make sure you have proper 3 pole connecting cables and dist. boards.

Or, the Thai way, "don't touch the case"

DC

[Gary A]

The ground in my wall socket? What's that? I live in Thailand. That 3rd ground wire costs money so we save that money here. I still see aluminum wire for sale here and many houses are wired with aluminum wire. I did buy a ground stake and when I get enough ambition to drive it in the ground I will ground my computer case. I have to wear my rubber flip flops if I want to touch the computer case now.

I was getting shocked off my computer case. I reversed the plug thus changed the polarity and still get a light with my cheap little screwdriver tester when I touch the case. I was told the white common was SUPPOSED to be grounded at the pole. Obviously mine is NOT. The point being is that if you are in any position to do it you should make sure you have a separate ground. It's interesting that the ground wire I insisted on for my shower is red. LOL!

<{POST_SNAPBACK}>

The reason you are getting a tickle off the computer case is not that the polarity is wrong or that the neutral is not grounded (actually an ungrounded neutral will mean you DON'T get a shock). Computers all have a mains inlet filter, these MUST be correctly grounded or the case will float at around 115 volts, not going to be lethal but rather unpleasant. Check the ground in your wall socket and make sure you have proper 3 pole connecting cables and dist. boards.

Or, the Thai way, "don't touch the case"

DC

<{POST_SNAPBACK}>

[buadhai]

Staying for a while in a Moo Baan here in Korat. The electric poles seem to have four wires, but only two go to each house.

Is it correct that one of those is hot and the other neutral?

In my house there is an old fashioned wiring board consisting of a main fuse and three circuit breakers.

We want to put an air con in one of the bedrooms, but the family says we have to have a new meter installed. It seems we will need more than a meter. Probably a new breaker panel and, perhaps, bigger drop lines.

As far as I can see, there are no ground (earth) lines anywhere in the house.

Anything I should watch out for in having the service and breaker panel upgraded?

(I built and wired my last house myself, but things seem sufficiently mysterious here that I plan to have this done by a pro....)

TIA

[lopburi3]

Things are pretty much the same as the 120 volt US system but at 230v so you do not need multi phase power lines to home for electric range/dryer and such - two wires in will do ya.

The two wires coming in will be one phase 230v power at 50hz. Your house is normal not having a ground wire as it is only recently that they have become common. You probably now have what is labeled a 5 amp electric meter (will have 5-15 written in it). This is really too small to be running much air con but you might get by with a small unit in bedroom without a change. Next step up is the 15 amp service (15-45 amps) which is enough to power multi air conditioners and a normal US style house and will probably also require a new line to house from meter and to feed. That is probably what you should be looking at. With that you will probably need to replace your main fuse to a larger one and I would highly recommend installing a Safe-T-Cut type breaker/ECLB GFI at this time as it will help protect you at a very small price. If you not adverse to spending a small amount for added protection and convenience you might consider rewire of house so that ground wire can be installed and probably wire size be increased (they tend to buy small for save money). Work and wire is not really all that expensive and you might arrange a reduction in rent from owner.

Electric panels and breakers are available here like in US so if you upgrade I would go with them rather than the single breakers of old that are often used here.

[buadhai]

Thanks so much lopburi. Pretty much what I assumed, but nice to have it confirmed. I will have the meter and lines upgraded and add a breaker box and Safe-T-Cut. I saw both at Home Pro for not that much money. Since this is just a temporary stay, I probably won't have the whole house rewired, but I think grounding the new circuits is a good idea.

Your help is much appreciated.

[Crossy]

The ground in my wall socket? What's that? I live in Thailand.  That 3rd ground wire costs money so we save that money here. I still see aluminum wire for sale here and many houses are wired with aluminum wire. I did buy a ground stake and when I get enough ambition to drive it in the ground I will ground my computer case. I have to wear my rubber flip flops if I want to touch the computer case now. 

I was getting shocked off my computer case. I reversed the plug thus changed the polarity and still get a light with my cheap little screwdriver tester when I touch the case. I was told the white common was SUPPOSED to be grounded at the pole. Obviously mine is NOT. The point being is that if you are in any position to do it you should make sure you have a separate ground. It's interesting that the ground wire I insisted on for my shower is red. LOL!

The reason you are getting a tickle off the computer case is not that the polarity is wrong or that the neutral is not grounded (actually an ungrounded neutral will mean you DON'T get a shock). Computers all have a mains inlet filter, these MUST be correctly grounded or the case will float at around 115 volts, not going to be lethal but rather unpleasant. Check the ground in your wall socket and make sure you have proper 3 pole connecting cables and dist. boards.

Or, the Thai way, "don't touch the case"

DC

We have 3 pole sockets in our condo. (Pathum Thani), amazingly the grounds are actually wired, even more amazing is that the ground wire is grounded (actually to the iron water pipe).

[andy50]

hi crossy, when you say that the earth wire is connected to an iron water pipe--does this pipe go underground?or is it within the flat?

in other words,is it the main water supply pipe coming into your flat?or is the main water supply pipe made of plastic?if it is ,then the connecting of an earth wire to any metal pipes within the flat would be usless and very dangerous

you must get an earth stake/rod and hammer it into the ground ,then use that as your main earthing point,(not so easy in a condo!)

but if the iron pipe you refer to is the main suppy pipe and goes underground with no plastic pipe joined in between, it is probably ok to use for earthing, as any fault current can be conducted away into the ground thus tripping the circuit breaker on the faulty circuit cheers-- andy (approved electrician 16th ed )

Edited April 11, 2005 by andy50

[lopburi3]

If you have any doubts as to having ground attached to something useful multi meters are very cheap these days and can be quite useful for battery testing in daily use. Lotus and other stores will have them in wall packs in the hardware section.

Use highest AC voltage setting (some will have a switch to select AC/DC as well as range for various type tests) and carefully put leads into socket - should read about 230v across hot/neutral and the same from the hot side to ground. If you get zero or a lower reading from hot side to ground it is not a good connection or not a good ground. If you are all thumbs have someone else do it; but as long as you are careful it is not very dangerous.

A very bad practice here is to sell outlet strips that appear to have a ground but in fact do not. Key is to look for a three prong plug when you buy (probably with an adapter to two pins included). Buy that type and get rid of the adapter.

[alex100]

If you need any advice on any aspect of DIY look at the following web site. www.screwfixdirect.com there is a forum where you can ask questions of any trade and answers will be given by tradesmen.

[brianbrain]

I'm with the others in saying 'if you don't know how to find the live wire don't connect anything'.

Get your condo. odd-job to do it. It is not worth risking getting fried.

<{POST_SNAPBACK}>

Getting the odd-job man to do it seems like a certain death to me!

[Ijustwannateach]

I was getting shocked off my computer case. I reversed the plug thus changed the polarity and still get a light with my cheap little screwdriver tester when I touch the case. I was told the white common was SUPPOSED to be grounded at the pole. Obviously mine is NOT. The point being is that if you are in any position to do it you should make sure you have a separate ground. It's interesting that the ground wire I insisted on for my shower is red. LOL!

<{POST_SNAPBACK}>

The reason you are getting a tickle off the computer case is not that the polarity is wrong or that the neutral is not grounded (actually an ungrounded neutral will mean you DON'T get a shock). Computers all have a mains inlet filter, these MUST be correctly grounded or the case will float at around 115 volts, not going to be lethal but rather unpleasant. Check the ground in your wall socket and make sure you have proper 3 pole connecting cables and dist. boards.

Or, the Thai way, "don't touch the case"

DC

<{POST_SNAPBACK}>

I've been wondering what to do about this myself. I have a 'tickly' computer case, and after doing a bit of research on the Internet find that the voltage which can damage computer memory and other components is actually less than what is detectable by your bare hands- in other words, if you case is ticklish, probably your computer is already in the process of being damaged by the inappropriately high charge. Is my only choice to ask the condo to fix the problem or move out?

"Steven"

[andy50]

If you have any doubts as to having ground attached to something useful multi meters are very cheap these days and can be quite useful for battery testing in daily use.  Lotus and other stores will have them in wall packs in the hardware section.

Use highest AC voltage setting (some will have a switch to select AC/DC as well as range for various type tests) and carefully put leads into socket - should read about 230v across hot/neutral and the same from the hot side to ground.  If you get zero or a lower reading from hot side to ground it is not a good connection or not a good ground.  If you are all thumbs have someone else do it; but as long as you are careful it is not very dangerous.

A very bad practice here is to sell outlet strips that appear to have a ground but in fact do not.  Key is to look for a three prong plug when you buy (probably with an adapter to two pins included).  Buy that type and get rid of the adapter.

<{POST_SNAPBACK}>

hi lopburi,the only prob is the rccd trips when u do that!(unless u bypass it)

[lopburi3]

If you have any doubts as to having ground attached to something useful multi meters are very cheap these days and can be quite useful for battery testing in daily use.  Lotus and other stores will have them in wall packs in the hardware section.

Use highest AC voltage setting (some will have a switch to select AC/DC as well as range for various type tests) and carefully put leads into socket - should read about 230v across hot/neutral and the same from the hot side to ground.  If you get zero or a lower reading from hot side to ground it is not a good connection or not a good ground.  If you are all thumbs have someone else do it; but as long as you are careful it is not very dangerous.

A very bad practice here is to sell outlet strips that appear to have a ground but in fact do not.  Key is to look for a three prong plug when you buy (probably with an adapter to two pins included).  Buy that type and get rid of the adapter.

<{POST_SNAPBACK}>

hi lopburi,the only prob is the rccd trips when u do that!(unless u bypass it)

<{POST_SNAPBACK}>

Then you must have a defective meter as you should not draw enough current to trip the RCCD with a solid state meter in the volts position. Does not trip for me.