Domestic Electrical Wiring

[elkangorito]

Due to the large amount of people posting questions etc about the electrical wiring of their abode (house), I have decided to post some information that may be helpful. The information was totally created by myself & I am happy to answer any questions.

I have also recently requested information from the Thai Electrical Mechanical Contractors Association with regard to possible 'wiring rules' that may exist in Thailand. I'll keep people informed of any response from them.

The below attachment illustrates a domestic electrical system. I have based it upon the NZ/AS 3000:2000 Wiring Rules (Australia). I hope it is easy for laymen to understand. My ultimate hope is that it will help to put an end to the numerous posts in different forum topics. For example, people who have problems with sensitive equipment (computers, stereos etc) generally will not associate their problem with that of an electrical nature. Since this could be the case, I thought it a good idea to begin this post.

[Morden]

Thanks for taking the trouble to post the diagram, elkangorito. A picture speaks a thousand words!

[elkangorito]

Thanks for taking the trouble to post the diagram, elkangorito. A picture speaks a thousand words!

My pleasure Morden. I plan to add other info such as cable selection, maximum demand calculation, circuit breaker selection etc etc etc. I'll try to do this on a weekly basis.

[Crossy]

Spot on mate

Only one comment, maybe we should have a 'posh' version of the consumer unit (distribution board) with ELCB protection for portable appliances but without ELCB for lighting and 'essential supply' (fridge, freezer etc.).

EDIT Mods, we should get this thread pinned, such an important subject, I'll vouch for elkangorito being a qualified and competant electrician. Ignore what he says at your peril!!

[elkangorito]

Spot on mate

Only one comment, maybe we should have a 'posh' version of the consumer unit (distribution board) with ELCB protection for portable appliances but without ELCB for lighting and 'essential supply' (fridge, freezer etc.).

Hi Crossy.

By all means mate I would certainly welcome your input on this topic. I agree that lighting circuits do not necessarily need to be ELCB protected but I have recommended (in the attachment) that a maximum of half of the lighting circuits be ELCB protected, should the consumer wish to do so.

Of course, the attachment only displays standard circuit breakers but obviously these can be exchanged for ELCB's as required.

If it's ok with you, I'd like you to give me a second opinion before I post info. I'll do this by PM if ok with you. 2 heads are better than one.

Whadoya reckon?

[bcross2001]

Spot on mate

Only one comment, maybe we should have a 'posh' version of the consumer unit (distribution board) with ELCB protection for portable appliances but without ELCB for lighting and 'essential supply' (fridge, freezer etc.).

EDIT Mods, we should get this thread pinned, such an important subject, I'll vouch for elkangorito being a qualified and competant electrician. Ignore what he says at your peril!!

Hey Guy's - This could not have come at a better time - we are about to start construction on a new home - please keep it coming - can you address the difference between a standard circuit breaker and an ELCB?

I also have purchased from the U S a commercial lighting protection circuit - I feel this is an excellent first line of protection in this enviroment.

thanks again and keep it comin

Barry

[elkangorito]

Spot on mate

Only one comment, maybe we should have a 'posh' version of the consumer unit (distribution board) with ELCB protection for portable appliances but without ELCB for lighting and 'essential supply' (fridge, freezer etc.).

EDIT Mods, we should get this thread pinned, such an important subject, I'll vouch for elkangorito being a qualified and competant electrician. Ignore what he says at your peril!!

Hey Guy's - This could not have come at a better time - we are about to start construction on a new home - please keep it coming - can you address the difference between a standard circuit breaker and an ELCB?

I also have purchased from the U S a commercial lighting protection circuit - I feel this is an excellent first line of protection in this enviroment.

thanks again and keep it comin

Barry

Hi Barry.

Can you please provide more details about this "commercial lighting protection cuicuit"? Why do you feel that it is an "excellent first line of protection in this enviroment"?

I/we will be addressing the issues you speak of (ELCB's), in the near future (maybe later this week if I can get my bum into gear).

[robint]

Electrical wiring is one of many pet hates in the los. thai wiring at the user level is completely incompetent and unsafe judged against europeean stands - i wont even beging to mention on how many accounts but its a national disgrace.

the flang can best protect his domestic residence by installing an RCD safety breaker (earlier called an ELCB and also named a GFI in the states. Its around 1500 baht in homepro and can be part of proper distribution board (as made by Square D, one of the better makes)

It is an invaluable protection for your family BUT

be aware

a) Much of thai electrical goods is very shoddy electrically which means that you will get earth leaks in time - a rice cooker is a typical example - sometimes lethal. so this may result in nuisance trips or intermittant trips.

Most existing witring will be 2 wire and the RCD is an essential protection, but a 3 wire Euro pattern system is preferable (available in homepro and typically seen on PC peripherals. but this needs a proper earth rod installed in the ground. this may increase the number of nuisance trips.

c) If you use an earth rod, dont put it anywhere near an aerail mast as a lightening strike may blow your safety breaker without you knowing. this happened to me on my shower heater and the safety trip no longer worked - and I DIDNT KNOW i was unprotected.

d) RCDS are essential for electric showers (usually built in to the unit) and also for any equipment to be used outside in the yard. To be really safe you should use a step down transformer 200/110 and 110 volts machinery but its diifficlt to find here.

e) PC power supplies are notoriously leaky and shocking so you may not be able to use this via you RCD cisrcuit. You will have to provide a separate supply and its own earth rod - as i do.

Still alive but I know of some who are not.

[elkangorito]

Thanks for your post Robin but there some things that you said that need to addressed. My comments are in red.

Electrical wiring is one of many pet hates in the los. thai wiring at the user level is completely incompetent and unsafe judged against europeean stands - i wont even beging to mention on how many accounts but its a national disgrace. I fully agree.

the flang can best protect his domestic residence by installing an RCD safety breaker (earlier called an ELCB and also named a GFI in the states. Its around 1500 baht in homepro and can be part of proper distribution board (as made by Square D, one of the better makes). This is not entirely true. The BEST & FOREMOST form of protection is a correctly earthed MEN system employed at the installation. Earth Leakage Protection devices are electronic & are therefore, apt to fail. To put your life TOTALLY in the hands of one of these devices is foolishness.

It is an invaluable ADDED protection for your family BUT

be aware

a) Much of thai electrical goods is very shoddy electrically which means that you will get earth leaks in time - a rice cooker is a typical example - sometimes lethal. so this may result in nuisance trips or intermittant trips. A proper earthing system & an MEN link will fix this provided the appliance is adequately earthed.

Most existing witring will be 2 wire and the RCD is an essential protection, but a 3 wire Euro pattern system is preferable (available in homepro and typically seen on PC peripherals. but this needs a proper earth rod installed in the ground. this may increase the number of nuisance trips. The addition of Earth rods do not cause nuisance trips...unless equipment is faulty. In such a case, the fault is easily detected & the device is repaired/replaced.

c) If you use an earth rod, dont put it anywhere near an aerail mast as a lightening strike may blow your safety breaker without you knowing. this happened to me on my shower heater and the safety trip no longer worked - and I DIDNT KNOW i was unprotected. There is absolutely no evidence to say that earth rods attract lightning. On the other hand, a lack of earth rods will increase the risk of death should lightning strike an installation. After a lightning strike (secondary or primary), the user is advised to have all electrical protection tested for correct operation. The safest option is to replace all protection devices. This is rarely done as it is not generally necessary unless a direct strike has destroyed equipment.

d) RCDS are essential for electric showers (usually built in to the unit) and also for any equipment to be used outside in the yard. To be really safe you should use a step down transformer 200/110 and 110 volts machinery but its diifficlt to find here. If you indicate the use of a 'stepdown transformer', be sure to know what you are talking about. The technically safe 'low' voltage is any voltage less than 32 volts RMS. Contrary to popular belief, 110v is as dangerous as 220v.

e) PC power supplies are notoriously leaky and shocking so you may not be able to use this via you RCD cisrcuit. You will have to provide a separate supply and its own earth rod - as i do. Many appliances are 'leaky & shocking' because an appropriate earthing system is not used together with an appropriate MEN link. Again, the installation of an appropriate earthing system & an MEN link will resolve these problems. There is no such thing as a 'non leaky' appliance. For this reason, the MEN system together with appropriate earthing was introduced.

Still alive but I know of some who are not. If you continually trust your RCD's, you may not be alive much longer.

[lopburi3]

Elkangorito has strong views on RCD and I do not agree with him on that point. RCD's save lives and that is why they are required in the US to be installed in danger areas such as bath and pool. In Thailand, where you often are barefoot on cement floors and suspect wiring I would consider that anywhere is dangerous. For that reason I highly recommend them. When, and if, you can install a three wire, grounded system by all means do so. You should have both. But with or without; the RCD can provide protection to a high level.

[Crossy]

Elkangorito has strong views on RCD and I do not agree with him on that point. RCD's save lives and that is why they are required in the US to be installed in danger areas such as bath and pool. In Thailand, where you often are barefoot on cement floors and suspect wiring I would consider that anywhere is dangerous. For that reason I highly recommend them. When, and if, you can install a three wire, grounded system by all means do so. You should have both. But with or without; the RCD can provide protection to a high level.

I do agree.

I would NEVER install a domestic system WITHOUT and ELCB covering the appliance outlets and water heaters. The use of an ELCB together with a correctly implemented MEN system will yield an arrangement where it should be pretty well impossible to get a dangerous shock. This is the arrangement as used in the UK and Oz (I believe the US is moving towards MEN systems, but this is complicated by the use of split-phase supplies for 110 and 220V).

I stress the correctly implemented as it would seem that many rural supplies don't ground the neutral at multiple points (only at the transformer) reducing the efficiency of the MEN system and possibly introducing a hazard under certain fault conditions. If this is the case I would NOT recommend the use of a MEN link (this is one point where I disagree with elkangorito).

[elkangorito]

Elkangorito has strong views on RCD and I do not agree with him on that point. RCD's save lives and that is why they are required in the US to be installed in danger areas such as bath and pool. In Thailand, where you often are barefoot on cement floors and suspect wiring I would consider that anywhere is dangerous. For that reason I highly recommend them. When, and if, you can install a three wire, grounded system by all means do so. You should have both. But with or without; the RCD can provide protection to a high level.

I do not dispute you Lop BUT the root of the problem is to address the REAL issue...THE EARTHING SYSTEM. To simply rely upon RCD's to 'save' lives is to rely upon electronic devices that CAN & DO fail. The MEN system of wiring is 'hard wired' & therefore has a greatly reduced likelyhood of failure, compared to that of electronic devices.

If one is truly concerned about electrical safety, then one will not opt for the 'band-aid' to a bad electrical installation. There is only 1 real solution for the truly safety conscious...INSTALL AN M.E.N. SYSTEM. The secondary protection will be the RCD's, which work very well under these conditions. This is a 'two fold' solution to a very misunderstood problem. If one can't afford this, by all means install RCD's in the meantime whilst saving to properly correct the REAL problem of inadequate earthing & a lack of an MEN link.

Those who insist that an RCD is all that is needed to sustain a 'safe' electrical household should think again...especially if the device fails & somebody dies, which is NOT unlikely. At least, with an MEN system, all correctly earthed appliances will be greatly safer. Since the Thai government do not seem to be interested in this subject, all I can advise is that ALL appliances be correctly earthed via an appropriate earthing system. This forum will certainly advise upon how such a thing can easily be achieved...if one is truly concerned with electrical safety.

[Crossy]

I think we should recommend the 'belt and braces' system.

ELCB, local ground spike AND an MEN link (subject to the multiple earthed neutral caveat).

Can't believe we could get much safer.

[bcross2001]

Thanks for your post Robin but there some things that you said that need to addressed. My comments are in red.

Electrical wiring is one of many pet hates in the los. thai wiring at the user level is completely incompetent and unsafe judged against europeean stands - i wont even beging to mention on how many accounts but its a national disgrace. I fully agree.

the flang can best protect his domestic residence by installing an RCD safety breaker (earlier called an ELCB and also named a GFI in the states. Its around 1500 baht in homepro and can be part of proper distribution board (as made by Square D, one of the better makes). This is not entirely true. The BEST & FOREMOST form of protection is a correctly earthed MEN system employed at the installation. Earth Leakage Protection devices are electronic & are therefore, apt to fail. To put your life TOTALLY in the hands of one of these devices is foolishness.

It is an invaluable ADDED protection for your family BUT

be aware

a) Much of thai electrical goods is very shoddy electrically which means that you will get earth leaks in time - a rice cooker is a typical example - sometimes lethal. so this may result in nuisance trips or intermittant trips. A proper earthing system & an MEN link will fix this provided the appliance is adequately earthed.

Most existing witring will be 2 wire and the RCD is an essential protection, but a 3 wire Euro pattern system is preferable (available in homepro and typically seen on PC peripherals. but this needs a proper earth rod installed in the ground. this may increase the number of nuisance trips. The addition of Earth rods do not cause nuisance trips...unless equipment is faulty. In such a case, the fault is easily detected & the device is repaired/replaced.

c) If you use an earth rod, dont put it anywhere near an aerail mast as a lightening strike may blow your safety breaker without you knowing. this happened to me on my shower heater and the safety trip no longer worked - and I DIDNT KNOW i was unprotected. There is absolutely no evidence to say that earth rods attract lightning. On the other hand, a lack of earth rods will increase the risk of death should lightning strike an installation. After a lightning strike (secondary or primary), the user is advised to have all electrical protection tested for correct operation. The safest option is to replace all protection devices. This is rarely done as it is not generally necessary unless a direct strike has destroyed equipment.

d) RCDS are essential for electric showers (usually built in to the unit) and also for any equipment to be used outside in the yard. To be really safe you should use a step down transformer 200/110 and 110 volts machinery but its diifficlt to find here. If you indicate the use of a 'stepdown transformer', be sure to know what you are talking about. The technically safe 'low' voltage is any voltage less than 32 volts RMS. Contrary to popular belief, 110v is as dangerous as 220v.

e) PC power supplies are notoriously leaky and shocking so you may not be able to use this via you RCD cisrcuit. You will have to provide a separate supply and its own earth rod - as i do. Many appliances are 'leaky & shocking' because an appropriate earthing system is not used together with an appropriate MEN link. Again, the installation of an appropriate earthing system & an MEN link will resolve these problems. There is no such thing as a 'non leaky' appliance. For this reason, the MEN system together with appropriate earthing was introduced.

Still alive but I know of some who are not. If you continually trust your RCD's, you may not be alive much longer.

Hello again from Barry

The surge protection system you enquired about is:

Tesco - http://www.tesco-online.com/products/se/TES240R.htm - 240 VAC Surge Arrester for residential and light industrial usage. Installed at wattmeter, service entry, or weatherhead, safety clamps and dissipates lightning induced safely AC line high voltage current impulses going to a residence.

In the discussion above keep in mind - if you increase voltage you lower current - and voltage doesn't kill you - its the current.

Barry

[bcross2001]

Spot on mate

Only one comment, maybe we should have a 'posh' version of the consumer unit (distribution board) with ELCB protection for portable appliances but without ELCB for lighting and 'essential supply' (fridge, freezer etc.).

EDIT Mods, we should get this thread pinned, such an important subject, I'll vouch for elkangorito being a qualified and competant electrician. Ignore what he says at your peril!!

Hey Guy's - This could not have come at a better time - we are about to start construction on a new home - please keep it coming - can you address the difference between a standard circuit breaker and an ELCB?

I also have purchased from the U S a commercial lighting protection circuit - I feel this is an excellent first line of protection in this enviroment.

thanks again and keep it comin

Barry

Hi Barry.

Can you please provide more details about this "commercial lighting protection cuicuit"? Why do you feel that it is an "excellent first line of protection in this enviroment"?

I/we will be addressing the issues you speak of (ELCB's), in the near future (maybe later this week if I can get my bum into gear).

In follow up to your question regards lighting protection - this unit is installed at the WattMeter.

I'm following your input regards home wiring systems - and feel with the proper home system in place and a Tesco unit out on the pole - I'd be in pretty good shape.

Barry

[Crossy]

Tesco - http://www.tesco-online.com/products/se/TES240R.htm - 240 VAC Surge Arrester for residential and light industrial usage. Installed at wattmeter, service entry, or weatherhead, safety clamps and dissipates lightning induced safely AC line high voltage current impulses going to a residence.

I'd be wary of using this device in Thailand.

Because we don't use the 110/220V split phase system I'm not certain that it would correctly clamp without the centre tap being connected. Without the actual diagram of the device I can't be certain though, maybe a mail to the manufacturer would be in order.

It certainly won't introduce a hazard, I'm more concerned about destroying the device and removing the protection that you think you have.

Also remember you won't be able to install it on the hot side of your main isolator (provided by the supply company).

EDIT. BTW, I still believe that this thread should be pinned, if only to keep all discussions on electrical safety in one location.

[bcross2001]

Tesco - http://www.tesco-online.com/products/se/TES240R.htm - 240 VAC Surge Arrester for residential and light industrial usage. Installed at wattmeter, service entry, or weatherhead, safety clamps and dissipates lightning induced safely AC line high voltage current impulses going to a residence.

I'd be wary of using this device in Thailand.

Because we don't use the 110/220V split phase system I'm not certain that it would correctly clamp without the centre tap being connected. Without the actual diagram of the device I can't be certain though, maybe a mail to the manufacturer would be in order.

It certainly won't introduce a hazard, I'm more concerned about destroying the device and removing the protection that you think you have.

Also remember you won't be able to install it on the hot side of your main isolator (provided by the supply company).

EDIT. BTW, I still believe that this thread should be pinned, if only to keep all discussions on electrical safety in one location.

I'll do that (get a diagram) I'm sure something can be worked out.

I'll also second the "pinned"

[elkangorito]

Elkangorito has strong views on RCD and I do not agree with him on that point. RCD's save lives and that is why they are required in the US to be installed in danger areas such as bath and pool. In Thailand, where you often are barefoot on cement floors and suspect wiring I would consider that anywhere is dangerous. For that reason I highly recommend them. When, and if, you can install a three wire, grounded system by all means do so. You should have both. But with or without; the RCD can provide protection to a high level.

I do agree.

I would NEVER install a domestic system WITHOUT and ELCB covering the appliance outlets and water heaters. The use of an ELCB together with a correctly implemented MEN system will yield an arrangement where it should be pretty well impossible to get a dangerous shock. This is the arrangement as used in the UK and Oz (I believe the US is moving towards MEN systems, but this is complicated by the use of split-phase supplies for 110 and 220V).

I stress the correctly implemented as it would seem that many rural supplies don't ground the neutral at multiple points (only at the transformer) reducing the efficiency of the MEN system and possibly introducing a hazard under certain fault conditions. If this is the case I would NOT recommend the use of a MEN link (this is one point where I disagree with elkangorito).

I see where you're coming from Crossy but I think it is still better to have an MEN system in any case. Afterall, earthing appliances without an MEN link being installed, would be a similar issue as to what you suggest. The only difference would be that the appliance has a reduced chance of creating a fault current large enough to trip the protective device as compared to no chance at all (no MEN link). In Thailand, Distribution Transformers are 'sometimes' earthed at the star point. This generally indicates that an 'earth return path', disregarding the impedance of such, still exists. Consequently, to NOT have an MEN link will simply reduce the chances of the protective device tripping in the case of a fault (increased impedance). Not forgetting that an MEN link utilises 2 return current paths whereas an earth electrode only 'hopes' that one current path is available & the imedance is low enough to allow protective devices to operate. An MEN system doubles your chances of safety & will not endanger the lives of anybody since high voltage transformers are usually 'star/delta connected (the star point is earthed only). Consequently, there is little chance of a high voltage feed being presented onto a lower voltage earthing system. Also, unless an SWER system is used (haven't seen one in Thailand yet although they may exist), there is no need to worry about mixing high voltage earths with low voltage earths.

It is obvious that Thailand needs to 'clean up their act' regarding earth fault impedances BUT the country does employ an MEN based system, which will (one way or another) help to trip protective devices should an MEN link be employed. Besides, an MEN link will do no harm providing the installation has only 1 Main Earth.

At the end of the day, I maintain that an MEN link in a Thai installation, will add to the electrical safety of your home. I don't believe that it can be, in any way, dangerous.

Sorry Dave...I guess we'll have to agree about disagreeing. Nonetheless, 2 heads are better than one.

[lopburi3]

Tesco - http://www.tesco-online.com/products/se/TES240R.htm - 240 VAC Surge Arrester for residential and light industrial usage. Installed at wattmeter, service entry, or weatherhead, safety clamps and dissipates lightning induced safely AC line high voltage current impulses going to a residence.

I'd be wary of using this device in Thailand.

Because we don't use the 110/220V split phase system I'm not certain that it would correctly clamp without the centre tap being connected. Without the actual diagram of the device I can't be certain though, maybe a mail to the manufacturer would be in order.

It certainly won't introduce a hazard, I'm more concerned about destroying the device and removing the protection that you think you have.

Also remember you won't be able to install it on the hot side of your main isolator (provided by the supply company).

EDIT. BTW, I still believe that this thread should be pinned, if only to keep all discussions on electrical safety in one location.

I'll do that (get a diagram) I'm sure something can be worked out.

I'll also second the "pinned"

You can not use that unit in Thailand. It is designed for 110v electric supply - the 240v rating on it is for two legs of 110v as they use in the US. Thailand use single phase 230v and that is nothing like what is used in the US. Dump it before you have problems. It will not work.

[Crossy]

Sorry Dave...I guess we'll have to agree about disagreeing. Nonetheless, 2 heads are better than one.

No problem Rob

I've got an IEE discussion paper somewhere that details the pros and cons of MEN / PME, I'll try to locate it, trouble is, it's hard copy, could be anywhere

The chief concern is the effect of an open circuit neutral, it is 'possible' that without an ELCB and with a crumby/no local earth that the appliance metalwork could approach phase voltage (pulled up by being connected to the, now floating, neutral). A truly multiple earthed neutral would limit the effect (many parallel paths to ground).

[elkangorito]

Tesco - http://www.tesco-online.com/products/se/TES240R.htm - 240 VAC Surge Arrester for residential and light industrial usage. Installed at wattmeter, service entry, or weatherhead, safety clamps and dissipates lightning induced safely AC line high voltage current impulses going to a residence.

I'd be wary of using this device in Thailand.

Because we don't use the 110/220V split phase system I'm not certain that it would correctly clamp without the centre tap being connected. Without the actual diagram of the device I can't be certain though, maybe a mail to the manufacturer would be in order.

It certainly won't introduce a hazard, I'm more concerned about destroying the device and removing the protection that you think you have.

Also remember you won't be able to install it on the hot side of your main isolator (provided by the supply company).

EDIT. BTW, I still believe that this thread should be pinned, if only to keep all discussions on electrical safety in one location.

I'll do that (get a diagram) I'm sure something can be worked out.

I'll also second the "pinned"

You can not use that unit in Thailand. It is designed for 110v electric supply - the 240v rating on it is for two legs of 110v as they use in the US. Thailand use single phase 230v and that is nothing like what is used in the US. Dump it before you have problems. It will not work.

I agree Lop. There are no clamping times (8/20 microseconds per unit fault current) & it does not state single phase characteristics. Do not buy this thing unless you have more money than sense.

[lopburi3]

Bcross2001: If you want such a unit believe you should look at the TES 208SE

But meters here are normally mounted on electric pole and do not believe Electric Company would be happy to see that attached to it - and it would probably be removed/destroyed if they do.

[elkangorito]

The next electrical advice installment is about 'Circuit types & quantities'. See the attached file.

Sorry Dave. As you know, haven't figured out how to add attachments to PM's yet although I have sent a message to the forum help.

[Crossy]

You can not use that unit in Thailand. It is designed for 110v electric supply - the 240v rating on it is for two legs of 110v as they use in the US. Thailand use single phase 230v and that is nothing like what is used in the US. Dump it before you have problems. It will not work.

I agree Lop. There are no clamping times (8/20 microseconds per unit fault current) & it does not state single phase characteristics. Do not buy this thing unless you have more money than sense.

This has to be a first, the three of us agreeing 100% on something :)

[elkangorito]

You can not use that unit in Thailand. It is designed for 110v electric supply - the 240v rating on it is for two legs of 110v as they use in the US. Thailand use single phase 230v and that is nothing like what is used in the US. Dump it before you have problems. It will not work.

I agree Lop. There are no clamping times (8/20 microseconds per unit fault current) & it does not state single phase characteristics. Do not buy this thing unless you have more money than sense.

This has to be a first, the three of us agreeing 100% on something

I guess it is a FIRST

Dave, is this you? --->

[Crossy]

The next electrical advice installment is about 'Circuit types & quantities'. See the attached file.

Sorry Dave. As you know, haven't figured out how to add attachments to PM's yet although I have sent a message to the forum help.

Just to drop in a small spanner

Our (rented) place is wired using the US codes of :-

Black - Hot/Live/Phase,

White - Neutral,

Green - Ground/earth.

Might be prudent to add this code to the document as an (allowable?) option.

EDIT:- Hey Rob, I 'aint no cowboy, heaven only knows why this smilie is called 'Dave' this is me

[elkangorito]

Sorry Dave...I guess we'll have to agree about disagreeing. Nonetheless, 2 heads are better than one.

No problem Rob

I've got an IEE discussion paper somewhere that details the pros and cons of MEN / PME, I'll try to locate it, trouble is, it's hard copy, could be anywhere

The chief concern is the effect of an open circuit neutral, it is 'possible' that without an ELCB and with a crumby/no local earth that the appliance metalwork could approach phase voltage (pulled up by being connected to the, now floating, neutral). A truly multiple earthed neutral would limit the effect (many parallel paths to ground).

Agreed Crossy (god!!! We must stop this 'agreeing'!!!)

But under conditions of a broken neutral (not an installation's neutral but a 'grid' neutral), many installations will suffer an unusually high voltage. Such voltages, as a result of a broken neutral, normaly destroy equipment.

Nonetheless, an RCD will help to protect the domestic installation (if the electronics survive the higher voltage created by the broken neutral). Bear in mind that the 'electronics' get their supply from the line side connection. What happens to this device if the supply voltage doubles?

[Crossy]

Nonetheless, an RCD will help to protect the domestic installation (if the electronics survive the higher voltage created by the broken neutral). Bear in mind that the 'electronics' get their supply from the line side connection. What happens to this device if the supply voltage doubles?

None of the RCD/ELCB/RCCB specs seem to define an overvoltage limit.

Since the electronics is very low power I would expect it to be reasonably protected, if it does fry the 'regular' testing (pushing the test button) will find it.

OK everybody, lets all go and push our ELCB 'Test' buttons now :)

Dark in here, isn't it??

[elkangorito]

The next electrical advice installment is about 'Circuit types & quantities'. See the attached file.

Sorry Dave. As you know, haven't figured out how to add attachments to PM's yet although I have sent a message to the forum help.

Just to drop in a small spanner

Our (rented) place is wired using the US codes of :-

Black - Hot/Live/Phase,

White - Neutral,

Green - Ground/earth.

Might be prudent to add this code to the document as an (allowable?) option.

EDIT:- Hey Rob, I 'aint no cowboy, heaven only knows why this smilie is called 'Dave' this is me

Hi (Crossy) . I couldn't help myself...sorry.

I am loathe to confuse a well entrenched standard...that is, RED is danger (active, positive[DC]) & black is neutral. It may be advisory to inform people of 'current' wiring colour codes but eventually, these colour codes will fall into Eurpean standards. Because of the MEN system being introduced into Thailand, the colour codes will soon follow suit as follows;

Active colours - brown (single phase), red, blue, yellow & white.

Neutral colours - black, blue (single phase).

Earth - green, green with yellow stripe.

These are the colours used in Australia, which has adopted the IEC/ISO codes.

[lopburi3]

Back to disagreement. The color code that has been used here is black/hot, grey/neutral, green/ground and that is the only type of wire you are likely to find for sale in my experience. Just being able to obtain three conductor wire was a real problem up until very recently. When we start saying black is neutral it becomes a real danger as in just about every house in Thailand it is hot.