Electric Question

[pgrin]

I just moved into a new house and all of the electric outlets are 3 prong. How can I confirm that the ground is truely grounded? With a volt meter, test light, stick my tongue in?

Thanks in advance,

P

[Crossy]

Quick and easy way is with a voltmeter, it won't however tell you how good your ground is, for that you need specialist kit

You should see:-

220V Live - Neutral

220V Live - Ground

0V Neutral - Ground (up to about 10V is acceptable, you'll rarely see 0V).

Do you have an ELCB / RCD / RCCB / GFI / Safe-T-Cut? If not I suggest you get one installed, it will improve safety significantly.

You also should have a MEN link in your consumer unit (it links ground to incoming neutral).

Have a look here :- http://www.crossy.co.uk/wiring/ for some useful information (including what an MEN link is), post here if you have further queries.

[chownah]

Crossy,

Does your method actually show that the ground wire is grounded? Wouldn't you get the same results if the ground and neutral wires were connected together at some place and neither was grounded? Wouldn't it be better to visually inspect for a ground rod and a wire connecting the ground rod to etc.etc.?

Chownah

[bcross2001]

Quick and easy way is with a voltmeter, it won't however tell you how good your ground is, for that you need specialist kit

You should see:-

220V Live - Neutral

220V Live - Ground

0V Neutral - Ground (up to about 10V is acceptable, you'll rarely see 0V).

Do you have an ELCB / RCD / RCCB / GFI / Safe-T-Cut? If not I suggest you get one installed, it will improve safety significantly.

You also should have a MEN link in your consumer unit (it links ground to incoming neutral).

Have a look here :- http://www.crossy.co.uk/wiring/ for some useful information (including what an MEN link is), post here if you have further queries.

Crossy

We are having a new home built and I have given the contractor your drawing for the MEM installation - how can I be sure (how do I test) that all the ground wires are connected and that the installation conforms to your drawing?

B Cross

[lingling]

Quick and easy way is with a voltmeter, it won't however tell you how good your ground is, for that you need specialist kit

Voltmeter and a light bulb is all you need. Hook up the bulb between live and ground and then measure the voltage diff between neutral and ground and ohm's law will tell you the rest. No need for any "specialist kit". And make sure everyone is keeping their hands off supposedly grounded equipment throughout the house/installation while you are doing this, just in case the ground is not grounded.

You should see:-

220V Live - Neutral

220V Live - Ground

0V Neutral - Ground (up to about 10V is acceptable, you'll rarely see 0V).

Do you have an ELCB / RCD / RCCB / GFI / Safe-T-Cut? If not I suggest you get one installed, it will improve safety significantly.

You also should have a MEN link in your consumer unit (it links ground to incoming neutral).

If you have a MEN link and can see a 10V diff between neutral and ground, something is wrong. A few millivolts, not more than that if you have a MEN link.

Anyway, why do they still do the MEN link thing here? Most western [european] countries abandoned that years ago. Any particular reason to continue doing it here (bad grounding at the village transformer, spikes, ghosts, ...?), or is it just because of outdated regulations and best practices?

[Crossy]

Quick and easy way is with a voltmeter, it won't however tell you how good your ground is, for that you need specialist kit

Voltmeter and a light bulb is all you need. Hook up the bulb between live and ground and then measure the voltage diff between neutral and ground and ohm's law will tell you the rest. No need for any "specialist kit". And make sure everyone is keeping their hands off supposedly grounded equipment throughout the house/installation while you are doing this, just in case the ground is not grounded. Fine, that will happily drop the ELCB, still won't tell you if your ground is good though

You should see:-

220V Live - Neutral

220V Live - Ground

0V Neutral - Ground (up to about 10V is acceptable, you'll rarely see 0V).

Do you have an ELCB / RCD / RCCB / GFI / Safe-T-Cut? If not I suggest you get one installed, it will improve safety significantly.

You also should have a MEN link in your consumer unit (it links ground to incoming neutral).

If you have a MEN link and can see a 10V diff between neutral and ground, something is wrong. A few millivolts, not more than that if you have a MEN link. Very true, but we're not necessarily assuming a MEN system as yet are we. You need to do all the voltage measurements first, that will give you a good idea that you actually have a ground, then (if you have no ELCB) you can get your bulb out.

Anyway, why do they still do the MEN link thing here? Most western [european] countries abandoned that years ago. Any particular reason to continue doing it here (bad grounding at the village transformer, spikes, ghosts, ...?), or is it just because of outdated regulations and best practices? Hmmm, MEN (or PME as it's known in Europe) is certainly not an outmoded system, in fact it is the preferred system for DOMESTIC installations, industrial and data centre installations are a different kettle of fish mind. Download the IEE regs 17th edition (released for public comment) from the IEE site.

Why is it that every time a qualified sparks says ANYTHING on this board about grounding all the closet electricians and self confessed rice farmers pop out of the woodwork and start questioning his judgement?? I don't advise people how to grow rice.

Bugger it, go and kill yourselves I don't give a flying fart!!!!

Edited May 15, 2007 by Crossy

[Crossy]

OK less Chang (actually Kingfisher, I'm stuck in Delhi) equals more lucid answers

Crossy,

Does your method actually show that the ground wire is grounded? Wouldn't you get the same results if the ground and neutral wires were connected together at some place and neither was grounded? Wouldn't it be better to visually inspect for a ground rod and a wire connecting the ground rod to etc.etc.?

Chownah

Absolutely, a visual is always a good idea, but it's never wise to rely solely on looking at things if you have some basic test gear

You are correct in your assertion that connecting neutral and ground at some point will give the same result (in fact this is an acceptable installation in some countries including certain installation types in the UK) although the neutral is always grounded at the Tx.

Edited May 16, 2007 by Crossy

[Crossy]

We are having a new home built and I have given the contractor your drawing for the MEM installation - how can I be sure (how do I test) that all the ground wires are connected and that the installation conforms to your drawing?

The voltmeter test at each outlet will demonstate that the grounds at least go somewhere approximating to earth.

You can visually inspect for the MEN link and the presence of a ground spike. It's also worth counting the connections to the ground bar, should be the same as the number of breakers plus the MEN link and connection to the ground spike.

Disconnect the MEN link (power off first and insulate the bare end, can't be too careful) and repeat the voltmeter test to give some confidence that the ground spike is connected and at least somewhat functional.

[Naam]

Why is it that every time a qualified sparks says ANYTHING on this board about grounding all the closet electricians and self confessed rice farmers pop out of the woodwork and start questioning his judgement?? I don't advise people how to grow rice.

easy crossy, easy...

[Crossy]

Why is it that every time a qualified sparks says ANYTHING on this board about grounding all the closet electricians and self confessed rice farmers pop out of the woodwork and start questioning his judgement?? I don't advise people how to grow rice.

easy crossy, easy...

:) No worries Doc, Kingfisher powered post, I'm (more) sober now

[astral]

IMHO it was a deserved response...............

Crossy has proved his credentials time and again in this forum.

No action needed, if fact it gave me a good laugh.

[lingling]

Fine, that will happily drop the ELCB, still won't tell you if your ground is good though

Disable or bypass the ELCB and disconnect the MEN first. All locally made ones have an override switch, and a superstar electrician such as yourself should be able to bypass it without frying yourself or need any "specialist kit".

Why is it that every time a qualified sparks says ANYTHING on this board about grounding all the closet electricians and self confessed rice farmers pop out of the woodwork and start questioning his judgement?? I don't advise people how to grow rice.

Why is it that electricians think that a couple of years of training on how to install wall outlets without frying themselves and installing domestic electrical systems turn them into qualified engineers? I am not a rice farmer.

My colleague who is certified to do and supervise installations for up to 400kV in all EU countries just told me that he hasn't seen a MEN link in any new installation in Europe in the last 30 or so years, but that Britain may be an exception as brits have difficulties adapting to new things. He also told me that in some countries it would be downright illegal to install one, and in some it would simply blow a fuse. I asked a simple question if there is some special reason to have one here - if you don't know the answer it is ok to just say that you don't have a clue without resorting to being an a-hole.

You can continue here if you don't know or understand ohm's law:

http://en.wikipedia.org/wiki/Ohm's_law

Edited May 16, 2007 by lingling

[elkangorito]

Just a few words....

Disable or bypass the ELCB and disconnect the MEN first. All locally made ones have an override switch, and a superstar electrician such as yourself should be able to bypass it without frying yourself or need any "specialist kit".

There is no need to touch the MEN link unless it needs repair or upgrading. The Earth Loop Impedance should be tested prior to installation energisation therefore rendering all this 'disconnecting' redundant.

Why is it that electricians think that a couple of years of training on how to install wall outlets without frying themselves and installing domestic electrical systems turn them into qualified engineers? I am not a rice farmer.

The actual training for an Australian electrician is 3 years college & 4 years 'hands on' experience. Even after this, it still takes another 2 to 4 years to be any good. Also, it all depends upon where one did his/her apprenticeship & also what he/she did after the apprenticeship.

My colleague who is certified to do and supervise installations for up to 400kV in all EU countries just told me that he hasn't seen a MEN link in any new installation in Europe in the last 30 or so years, but that Britain may be an exception as brits have difficulties adapting to new things. He also told me that in some countries it would be downright illegal to install one, and in some it would simply blow a fuse. I asked a simple question if there is some special reason to have one here - if you don't know the answer it is ok to just say that you don't have a clue without resorting to being an a-hole.

Obviously you know nothing about electrical distribution systems. The TT system (as used in Australia & Thailand) prescribes the use of an MEN link. Other systems do not as it could be dangerous (as you say).

You can continue here if you don't know or understand ohm's law:

http://en.wikipedia.org/wiki/Ohm's_law

I wouldn't trust anything off wikipedia.

Well, since you seem to have the energy to waste on half-baked answers, I'll leave it up to you & the others. If all goes well, nobody will die or get injured from the inherently dangerous comments made by the closet electricians. It appears that proven procedures & rules don't apply to closet electricians.

Have fun.

[Crossy]

Fine, that will happily drop the ELCB, still won't tell you if your ground is good though

Disable or bypass the ELCB and disconnect the MEN first. All locally made ones have an override switch, and a superstar electrician such as yourself should be able to bypass it without frying yourself or need any "specialist kit". Well, as you surmise, I am more than capable of disabling the ELCB, HOWEVER the OP is not, if he was he wouldn't be asking how to check his grounding. I don't like the adjustable ELCB units because they CAN be disabled, I would never recommend their use particularly as there are better smaller units available that will fit directly into your consumer unit.

Why is it that every time a qualified sparks says ANYTHING on this board about grounding all the closet electricians and self confessed rice farmers pop out of the woodwork and start questioning his judgement?? I don't advise people how to grow rice.

Why is it that electricians think that a couple of years of training on how to install wall outlets without frying themselves and installing domestic electrical systems turn them into qualified engineers? I am not a rice farmer. The 'Rice Farmer' quip was not aimed at you (you are the 'closet electrician'), I do apologise if you didn't read the full text particularly the 'self confessed' bit. BTW as a 25 year member of the IEE (recently re-branded as the IET, IMHO a bad move on the institute's part) with an engineering charter and Batchelors degree in Electrical and Electronc Engineering I think I do qualify as an 'Engineer'.

My colleague who is certified to do and supervise installations for up to 400kV in all EU countries just told me that he hasn't seen a MEN link in any new installation in Europe in the last 30 or so years, but that Britain may be an exception as brits have difficulties adapting to new things. He also told me that in some countries it would be downright illegal to install one, and in some it would simply blow a fuse. Ok, your collegue will also know that the protection of HV distribution systems (which mainly don't have a neutral anyway) is a totally different kettle of fish to the protection of LV systems. I agree that in 'some' European countries the use of MEN is prohibited although they do use very similar systems that have Neutral and Earth sharing the same conductor (called the PEN) from the sub-station (which of course, eliminates the need for a MEN link as N & E are actually the same wire anyway).

I asked a simple question if there is some special reason to have one here - if you don't know the answer it is ok to just say that you don't have a clue without resorting to being an a-hole. To answer your question (sorry I didn't before). The Thai regulations such as they are, require the use of the MEN system, since we are in Thailand we should respect that. It's also true that many parts of the country are only just getting to grips with having grounding, let alone MEN. Not sure where my anus comes into the equation

You can continue here if you don't know or understand ohm's law:

http://en.wikipedia.org/wiki/Ohm's_law Never believe what Wiki has to say although in this case I think it's reasonable.

Edited May 17, 2007 by Crossy

[chownah]

I just moved into a new house and all of the electric outlets are 3 prong. How can I confirm that the ground is truely grounded? With a volt meter, test light, stick my tongue in?

Thanks in advance,

P

Pgrin,

I'm reasonably sure that you really don't want to sort through all of the mud slinging going on here so I'll try to give you my view directly.

It is my view that the only way you can be completely sure that an outlet is TRULY grounded is to trace the ground wire from the outlet back to the ground rod. If you can do this then you can be sure that the outlet is truly grounded....but....you can not be sure of the quality of the ground. The ground rod installation might be in dirt which does not make a very good contact with the ground rod or the dirt itself might not be a very good conductor of electricity so a seemingly good ground rod might not provide adequate grounding. An installed ground rod can be tested but it is not as simple as one might imagine at least from what I have read in other threads in this forum.

It is my view that testing an outlet in any way using testing equipment to compare voltage readings can not guarantee that an outlet is TRULY grounded although the procudure that Crossy described can make you reasonably sure that it is grounded....and as he pointed out, making sure that your grounding system is performing adequately is another problem altogether.

By the way, I am the rice farmer.

Chownah

[Crossy]

Pgrin,

I'm reasonably sure that you really don't want to sort through all of the mud slinging going on here so I'll try to give you my view directly.

...

...

By the way, I am the rice farmer.

Chownah

Shouldn't it be buffalo-dung slinging Chownah? I'm amazed you lasted nearly two days before biting at the 'rice farmer' bait.

I wouldn't class our exchanges as mud slinging, much more civilised than that (IIRC you've never questioned my integrity and definately not called me an a-hole). Certainly my tete-a-tete's with your good self do stimulate the old grey cells if only to find some suitable retort to the latest 'question'.

Yes, trace the wires and measure the voltages (helps if you can't see the wires), but as you so rightly imply an absolute verification requires specialist equipment together with the knowledge of how to use it and that just 'aint gonna happen.

And most importantly, fit a good ELCB!!!

Peace

Edited May 17, 2007 by Crossy

[chownah]

I'm amazed you lasted nearly two days before biting at the 'rice farmer' bait.

It is rice season now so I don't have time to get outraged as regularly as I have in the past. Most of the grounding issues I have now are how to get it plowed and mixed with water into a muddy mess since this is what rice likes to be planted into.

Chownah

[Naam]

The actual training for an Australian electrician is 3 years college & 4 years 'hands on' experience. Even after this, it still takes another 2 to 4 years to be any good.

hmmm... three years college is the basis in Oz to become an electrician? what's the definition of "college" in Australia pray tell?

[lingling]

To answer your question (sorry I didn't before). The Thai regulations such as they are, require the use of the MEN system, since we are in Thailand we should respect that. It's also true that many parts of the country are only just getting to grips with having grounding, let alone MEN. Not sure where my anus comes into the equation

Great answer, thanks. Sorry for me blowing a fuse at first, but you did get me boiling for a minute or so. You have my respect now.

Btw, off topic, but do you by any chance know of any local company that carries surge arresters that will fit on a din rail? I can't find them anywhere...

[Crossy]

To answer your question (sorry I didn't before). The Thai regulations such as they are, require the use of the MEN system, since we are in Thailand we should respect that. It's also true that many parts of the country are only just getting to grips with having grounding, let alone MEN. Not sure where my anus comes into the equation

Great answer, thanks. Sorry for me blowing a fuse at first, but you did get me boiling for a minute or so. You have my respect now.

Btw, off topic, but do you by any chance know of any local company that carries surge arresters that will fit on a din rail? I can't find them anywhere...

Apology accepted, no worries. It's sometimes extremely difficult to know who's what on an anonymous forum not helped by the odd Chang or five, respect both ways Even the rice farmer comes up with sensible (although sometimes antagonistic) observations

No solid lead on the surge arrestors though, no point looking in Homepro or anywhere like that (can't even get 3 core TPS there). Try giving these chaps a call http://www.schneider-electric.co.th/ they stock Square-D, Telemecanique, Clipsal and Merlin Gerin kit. The e-catalog certainly contains something like you want (search on 'surge') but it's not clear whether they're kept in-stock in Thailand.

Edited May 17, 2007 by Crossy

[blue eyes]

You have been given much good advice and a little,shall we different advice.One thing that I would like to add is the ground rod it self.This happened in the USA.When I had my electric redone after a rebuild of our home, there was to be a second ground rod installed as per the new updated code.The rods are to be 8 foot long each.After they had been driven into the ground I noticed a 2 foot peice of rod laying off to the side in the scrap pile.I asked the electrition about this and he said that the one rod he could not get it pounded into the ground anymore so he just cut it off. If I had not seen this I and the code inspecter would have never known.Moral of this story....Learn as much as you can about what you hire other people to do and watch as much as you can.Oh listen to crossy.

[huahin]

Quick and easy way is with a voltmeter, it won't however tell you how good your ground is, for that you need specialist kit

You should see:-

220V Live - Neutral

220V Live - Ground

0V Neutral - Ground (up to about 10V is acceptable, you'll rarely see 0V).

Do you have an ELCB / RCD / RCCB / GFI / Safe-T-Cut? If not I suggest you get one installed, it will improve safety significantly.

You also should have a MEN link in your consumer unit (it links ground to incoming neutral).

Have a look here :- http://www.crossy.co.uk/wiring/ for some useful information (including what an MEN link is), post here if you have further queries.

G'day again, I'm going to build a house at the end of the year, and I have been reading (as much as I can) the forum on various aspects of hous biulding. I'm not a builder or an electricion, so what are ELCB / RCD / RCCB / GFI / Safe-T-Cut? and what does each do, where do I find (shops) these things and how does one tell the builder/elect. that these are required.

Regards and thanks for the answers (more questions will no doubt follow)

[Crossy]

G'day again, I'm going to build a house at the end of the year, and I have been reading (as much as I can) the forum on various aspects of hous biulding. I'm not a builder or an electricion, so what are ELCB / RCD / RCCB / GFI / Safe-T-Cut? and what does each do, where do I find (shops) these things and how does one tell the builder/elect. that these are required.

Regards and thanks for the answers (more questions will no doubt follow)

Have a good poke around on the link referenced above http://www.crossy.co.uk/wiring simple dicussions of ELCB etc (look down the Grounding and Protection link) and some diagrams of how to wire up your home (your electrician should be able to understand and get the necessary bits from his wholesaler).

Edited May 24, 2007 by Crossy

[huahin]

Thanks for that Crossy, there seems to be so much information it's mind bogling.

[suanprig]

Ok. with all that said can anyone recommend an electrician in Chiang Mai that can attach this stuff to my house.?? [email protected]

[Mid]

The actual training for an Australian electrician is 3 years college & 4 years 'hands on' experience. Even after this, it still takes another 2 to 4 years to be any good.

hmmm... three years college is the basis in Oz to become an electrician? what's the definition of "college" in Australia pray tell?

tertiary