Question for any qualified electricians living in Isaan

[Trumpish]

I'm improving the electrics in my house (installing earth stakes and lines in a previously live/neutral only wiring setup. I notice that where a local electrician has installed some 3-pin sockets to accommodate an earth line, the live/neutral polarity has been reversed such that polarity (with the socket viewed with the earth connection to the right) is live at the bottom and neutral at the top. From what I've read. the reverse should apply, but I understand that in Thailand, fridges and such that only have 2-pin plugs reverse the polarity if required. either in the safe-T-cut box or in the appliance itself, so it may be a minor thing.

 

Can anyone tell me if I should restore the live neutral polarity such that the live is at the top and neutral at the bottom (again, with the earth connection in the socket being on the right).

 

All help and advice welcome, I'm doing it myself because the work of Thai electricians seems to be to be very inconsistent, and some of what I've seen worries me, and I'm arrogant enough to think I can at least make it safe.

 

ps. I'm using 1-metre earth stakes, which I think ought to be long enough - right or wrong? One safe earth circuit in the house done by a Thai shows <2v leakage and I know that's only a 30cm stake but my one previous effort shows too much leakage ( 50v), with the result I get a few tingles from attached usb equipment..

[ubonjoe]

Since this is not specific for Isaan i am moving this to the electrical forum. Check the pinned topics there and you will find some useful info.

[Crossy]

Leakage is measured in mA not V. What are you actually measuring?

 

The earth rod required by Thai regulations is 2.4m.

 

You should really have the polarity correct although 99.99% of modern appliances care not. How are you verifying the polarity?

 

 

[Trumpish]

57 minutes ago, Crossy said:

Leakage is measured in mA not V. What are you actually measuring?

 

The earth rod required by Thai regulations is 2.4m.

 

You should really have the polarity correct although 99.99% of modern appliances care not. How are you verifying the polarity?

 

 

 

 

Thanks for the reply.

 

I used a multimeter across P/E and N/E. Because the house was originally wired with 2 wires only, I am first doing the rooms with equipment which really needs earthing (mainly computer equipment.In the first room there are 6 earthed plug points. All are showing close to zero voltage across Live/Earth, but the second room is showing about a 50v difference, which I interpret as being a poor earth circuit. I have not tried to measure the amperage, I have just assumed it exists because there is a PD across L/E, which according to others shopuld be <2v or thereabouts.

 

What you say about polarity accords with what I understand, and also experience - all devices I connenct seem to work, although one person told me that incorrect polarity could cause (relatively minor) tingles from the casing of a portable disk drive (it only has 2 pins on the plug) and the cases of some connected devices. I have no way of knowing if this is true or not but I do get minor shocks sometimes from 2-pin USB devices, which I am proposing to fix by attaching a ground wire to the outside of the female USB connector (worked last time I did that). On balance, and unless you advise otherwise, I think that changing the polarity is not a priority.

 

Thoughts/advice welcome.

[Crossy]

L/E should be 220V.

 

N/E should be close to zero, 50V means no earth (floating, capacitive pickup).

 

 

[Trumpish]

18 minutes ago, Crossy said:

L/E should be 220V.

 

N/E should be close to zero, 50V means no earth (floating, capacitive pickup).

 

 

Thanks again Crossy. I should say I have been influenced by this: https:// www.youtube.com/ watch?v=QIdComJj7QU (remove spaces)

In the 1st room, the numbers are (give or take):

 

L/N circa 220v

L/E circa 220v

N/E circa 2v

 

In the second room, where I am thinking of replacing an older earth stake, I am getting:

 

L/N circa 220

L/E circa 170v <--- hence my interpretation of a bad earthing. 'Leakage' may be the wrong term, sorry.

N/E circa 2v

 

This is why I am thinking or replacing the earth circuit in room 2.

 

In both rooms, (one installed by an electrician and one by me, room 2 is the problem, installed by me) the earth stake is short (30 or 50 cm), yet room 1 earths pretty well according to the L/E multimeter reading (close to 220v). I am thinking of replacing room 2 with a 1m stake. Since the rods outside rooms 1 and 2 are the same and yet room to is ineffective, I suspect the ground under the house is too dry outside room 2 so I may install the new rod beyond the patio area which shelters the area from rain).

 

Is the 2.4m an absolute recommendation or to provide lightning coverage? I'm curious as to why stores would sell shorter stakes...

[Crossy]

Room 1 looks ok

 

Room 2 definitely looks like something floating, does the outlet in question actually power an appliance?

 

I doubt dry ground would give those readings, have you checked continuity from the rod to the outlet?

 

Just because the regulations say ...

 

EDIT If you still think it may be dry ground, the watering can is your friend.

 

[Trumpish]

Cheers. The rod from room 2 has been otherwise interfered with (wire and protruding section of the rod have been painted over by a helpful house painter) so I was proposing to insert the 1m rod a few meters away and see if that works better from an adjacent plug panel. If it does improve I will then connect the earths of both panels together. 

 

I have interpreted the voltages to mean that the earth line from room 2 is not providing a good earth. Yet the plugs all power appliances with 2 or 3 pins. I also suspect that the earth reading is what is causing occasional tingles from the USB equipment (usually 2-pin plugs but connected by the USB cable to the main computer, the outer case of which nips me occasionally). I am keen to get proper earthing where I operate the computer ewuipment and UPS (Isaan has quite a lot of power cuts I've noticed). Keen to get it safe and efficient.

 

Do you perchance live in NE? If so, do you happen to know of a decent European or American electrician? I am really hacked off with having to do the painting/decorating and electrical/water work by myself but (not to put too fine a point on it), the local tradesmen aren't really excellent.

 

Not how I envisaged spending my retirement. 

[carlyai]

"Do you perchance live in NE? If so, do you happen to know of a decent European or American electrician".

I know of a good Thai one in Mukdahan. He did most of my 3 phase house, and fixed up a big European house after the falang contractor stuffed some things up.
PM me for details.

But, you seem to be going well 'with a little help from your friends'.

Sent from my SM-J700F using Tapatalk

[Trumpish]

2 hours ago, carlyai said:

"Do you perchance live in NE? If so, do you happen to know of a decent European or American electrician".

I know of a good Thai one in Mukdahan. He did most of my 3 phase house, and fixed up a big European house after the falang contractor stuffed some things up.
PM me for details.

But, you seem to be going well 'with a little help from your friends'.

Sent from my SM-J700F using Tapatalk
 

I think Mukdahan is probably a bit far. But thanks very much for replying, greatly appreciated. Time to soldier on perhaps.

[carlyai]

Can't you connect the room 2 earth to the room 1 earth stake and see what happens?
If all Ok, then make room 1 earth stake the main earth.



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[RichCor]

OP,  are you creating individual earth points?

Does your CU / Breaker Box have a dedicated Earth Ground connection, and what distance. 

[aussie11950]

I would concentrate on getting an earth stake in ground that is not dry. Then connect to other earths.

Don't worry about N/L polarity, all appliances are immune to polarity reversal, just make sure a good earth is connected to the appliances with metal parts.

Microwave, computers fridge etc and your water heater.

Earth should be 2.5mm minimum, and consider installing an ELCB to your panel.

 

 

Sent from my iPhone using Tapatalk

 

[Trumpish]

13 hours ago, carlyai said:

Can't you connect the room 2 earth to the room 1 earth stake and see what happens?
If all Ok, then make room 1 earth stake the main earth.



Sent from my SM-J700F using Tapatalk
 

Could do but that means running a cable in the wall (with consequent redecoration). Multiple earth stakes seems to me to be the easiest option. I fixed an external plug today and it all worked fine. Thankfully.

[Trumpish]

9 hours ago, RichCor said:

OP,  are you creating individual earth points?

Does your CU / Breaker Box have a dedicated Earth Ground connection, and what distance. 

Yes, pretty much. If the guy who did the original job was any good he'd have run 3 cables in-wall and put a single earth line from the junction box. But he wasn't, so now I have to do each room where I want earthing individually. Luckily it's only the rooms with a new fridge (room already done by someone who wasn't a muppet), and the computer equipment roon (done by me, but I need to re-do with a longer stake and better wiring.

 

Living in Thailand has many advantages for me, but ready access to qualified tradesmen isn't one of them.

[Trumpish]

9 hours ago, aussie11950 said:

I would concentrate on getting an earth stake in ground that is not dry. Then connect to other earths.

Don't worry about N/L polarity, all appliances are immune to polarity reversal, just make sure a good earth is connected to the appliances with metal parts.

Microwave, computers fridge etc and your water heater.

Earth should be 2.5mm minimum, and consider installing an ELCB to your panel.

 

 

Sent from my iPhone using Tapatalk

 

Thanks for this. I did the fridge already, washing m/c today, and I did fix the polarity on that one - pretty easy so where's the harm? Using 1.5mm wire. All seems OK, for the rest, I'll leave it at L/N and follow your advice not to worry about the polarity. Wish I'd known all this before I had the house built, relying on Thai tradesmen truly sucks. Though I'm sure there are a lot of super-competent ones, just none of them live around here.

[Trumpish]

Many thaks to all for your assistance. I think I got it in hand now, again, thanks to all for your advice and willingness to help.

 

Cheers

[RichCor]

9 hours ago, aussie11950 said:

and consider installing an ELCB to your panel.

OP, as aussie11950 suggests, please look at having an RCD (Residual Current Device) installed if you don't already have one.

Relying on multiple earth points rather than a dedicate earth ground wire directly connected to your CU is problematic.   

 

Having an RCD in place ahead of the Mains Breaker, or at least on circuits that might potentially involve water or human interaction, can save someone's life. Grounded circuits are only part of the safety equation.

[Trumpish]

1 hour ago, RichCor said:

OP, as aussie11950 suggests, please look at having an RCD (Residual Current Device) installed if you don't already have one.

Relying on multiple earth points rather than a dedicate earth ground wire directly connected to your CU is problematic.   

 

Having an RCD in place ahead of the Mains Breaker, or at least on circuits that might potentially involve water or human interaction, can save someone's life. Grounded circuits are only part of the safety equation.

 

Many thanks for this advice. I have a Safe-T-Cut but I suspect no RCD as you suggest. That shouldn't be too hard to get, but I think where the Junction Box is concerned I'll have one of the locals do it. With appropriate oversight.

[RichCor]

Safe-T-Cut is a brand, but they primarily market Residual Current Devices.

 

If it has a 'TEST' button near a breaker, and when you press it the breaker 'opens' then most likely you have an RCD.

[carlyai]

@Trumpish

You can do the RCD yourself if there are no sparkies around.

I could be corrected on this, but you don't need to put it before the main breaker. You can turn the main breaker off, and comfortably install it after the main breaker. So main breaker, RCD, then feed to the house.
Get an RCD that doesn't have a switchable sensitivity that says 'bypass' or something like that. There is a temptation to switch to this position if there is a fault.
While you certainly must have a RCD, you can get RCD tripping problems that are not caused by a house fault.
My RCD trips if we get a lightning strike close, like about 300 m. I have heard they can also trip sometimes with pumps, but have not experienced that.





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[Trumpish]

14 hours ago, RichCor said:

Safe-T-Cut is a brand, but they primarily market Residual Current Devices.

 

If it has a 'TEST' button near a breaker, and when you press it the breaker 'opens' then most likely you have an RCD.

 

Thanks for this. Just checked and yes, there is a test button on a RCBO module . I knew that already, can't imagine why I didn't recognise it, I guess I just needed to be sure we were all talking about the same thing. Must be getting old.

 

Still, nice to know I already have what many are suggesting I should have...

 

Thanks to all.

[RichCor]

1 hour ago, Trumpish said:

Just checked and yes, there is a test button on a RCBO module .

So, now the question: Which Module??

 

As @Carlyai indicated in his post, an RCD can be placed in different locations to offer 'downstream' circuit protection. "Mains Breaker", "Split Panel" (some circuits, not all), "Individual Breaker" (only for that breaker), or even somewhere on a "Branch Circuit" (i.e.: the instant-on shower, fish pond, outdoor lighting, etc). 

 

Only connected wiring after an RCD is ever protected against electrical leak. 

You don't have to have whole house protection, but it's usually the easiest to implement.

 

So... where your RCD is located and what downstream circuits it's protecting is kinda important to identify. If it's only on one RCBO module, only the wiring connected to that module is protected.

[williet98248]

I had the same problem in my old house .  I hired a Thai electrician on a recommendation; told him I needed grounded circuits for computers and other appliances.  Expected him to rewire with three wire cable.  House was originally not grounded and two wire cable hot/ neutral wires to all sockets.  All two pin outlets.  He grounded the neutral bus bar in the box with a stake, installed three plug outlets to the two wire cable and bridged the ground screw to the neutral on each three way receptacle with a short wire.  I was skeptical but I have a plug in gadget that tells me by colored lights if the outlet is grounded, has an open or wired incorrectly.  It said all my three pin outlets were grounded and all my three pin appliances and computers are working properly with no leakage.  Never heard of such a thing.  I had him pull out the old manual reset safety cut as well and he replaced it with a digital safety cut that resets itself after a two minute delay.  So it is ready to go when the power is restored.  This after a three day holiday when I returned to find all my frozen food melted and everything in the fridges (two) wilted and no one around to reset the safety cut for the three days.  I used to get a power outages quite often even when all the houses around me had electricity.  A bolt of lightning kms away would do it.  With the new grounded system I experience fewer outages and only when the whole neighborhood has the same.  Happy guy.

[Trumpish]

1 hour ago, RichCor said:

So, now the question: Which Module??

 

As @Carlyai indicated in his post, an RCD can be placed in different locations to offer 'downstream' circuit protection. "Mains Breaker", "Split Panel" (some circuits, not all), "Individual Breaker" (only for that breaker), or even somewhere on a "Branch Circuit" (i.e.: the instant-on shower, fish pond, outdoor lighting, etc). 

 

Only connected wiring after an RCD is ever protected against electrical leak. 

You don't have to have whole house protection, but it's usually the easiest to implement.

 

So... where your RCD is located and what downstream circuits it's protecting is kinda important to identify. If it's only on one RCBO module, only the wiring connected to that module is protected.

 

Right. I thought I was making progress but now I'm muddled. Perhaps best to attach a pic of the Safe-T-Cut main panel (herewith):

 

I know that the cut-out works OK since we had a couple of shorts earlier this year as a result of some field mice nibbling at one of the downstairs in-ceiling cables, and that triggered the cut-off of all power in the house (the double-bar switch at the far left needed to be reset), but the relative location of the switches and the RCD module is something I don't quite understand. Perhaps the piccy will make it clearer. If advised by you guys, I am happy to get the thing replaced with a better model - I sympathised with williet98248 finding the contents of fridges spoiled!

 

[RichCor]

37 minutes ago, williet98248 said:

He grounded the neutral bus bar in the box with a stake, installed three plug outlets to the two wire cable and bridged the ground screw to the neutral on each three way receptacle with a short wire.  I was skeptical but I have a plug in gadget that tells me by colored lights if the outlet is grounded, has an open or wired incorrectly.  It said all my three pin outlets were grounded and all my three pin appliances and computers are working properly with no leakage.  Never heard of such a thing.  

You never heard of such a thing because it is illegal and potentially LETHAL.

 

1. If the neutral wire in the walls were ever to become disconnected/broken/etc, any 3-prong devices that were connected to the outlet (for example, a computer) would now have a live case. If you touched the case, you could be electrocuted.
2. This 'cheat' offers absolutely no Earth Ground Safety Protection

[RichCor]

11 minutes ago, Trumpish said:

Perhaps best to attach a pic of the Safe-T-Cut main panel (herewith):

 

On this particular Consumer Unit, the MAINS BREAKER (far left) leads directly to the RCD (mid panel) then on to the individual Breakers (far right). The RCD is integrated in the design of the panel.

 

Usually the only way to actually verify is to take off the cover trace the wires and bus connection. But in this instance I think your good.

 

Just remember to press the TEST button every once in a while to make sure the thing is still providing the protection feature.

[janclaes47]

9 minutes ago, RichCor said:

53 minutes ago, williet98248 said:

He grounded the neutral bus bar in the box with a stake, installed three plug outlets to the two wire cable and bridged the ground screw to the neutral on each three way receptacle with a short wire.  I was skeptical but I have a plug in gadget that tells me by colored lights if the outlet is grounded, has an open or wired incorrectly.  It said all my three pin outlets were grounded and all my three pin appliances and computers are working properly with no leakage.  Never heard of such a thing.  

You never heard of such a thing because it is illegal and potentially LETHAL.

 

1. If the neutral wire in the walls were ever to become disconnected/broken/etc, any 3-prong devices that were connected to the outlet (for example, a computer) would now have a live case. If you touched the case, you could be electrocuted.
2. This 'cheat' offers absolutely no Earth Ground Safety Protection

 

 

I'm not an electrician, but isn't it so that as soon as an appliance is operational the neutral becomes live?

 

So if the neutral is connected to the ground, a RCBO would trip immediately, or not?

 

[Trumpish]

Just now, RichCor said:

 

On this particular Consumer Unit, the MAINS BREAKER (far left) leads directly to the RCD (mid panel) then on to the individual Breakers (far right). The RCD is integrated in the design of the panel.

 

Usually the only way to actually verify is to take off the cover trace the wires and bus connection. But in this instance I think your good.

 

Just remember to press the TEST button every once in a while to make sure the thing is still providing the protection feature.

 

Excellent, that makes sense now. The only thing I can think needs doing right now is to move the microwave oven to an earthed 3-pin plug in another room, and away from the non-earthed 3-pin plug where it is.

 

Thanks again to one and all for the responses. Greatly appreciated.

[RichCor]

26 minutes ago, janclaes47 said:

1 hour ago, williet98248 said:

installed three plug outlets to the two wire cable and bridged the ground screw to the neutral on each three way receptacle with a short wire.

I'm not an electrician, but isn't it so that as soon as an appliance is operational the neutral becomes live?

So if the neutral is connected to the ground, a RCBO would trip immediately, or not?

 

The only thing this 'cheat' does is fool a plug tester (as normally Neutral and Earth Ground are connected upstream, usually at the CU)

 

// edit: I should add that what this 'cheat' or socket 'bootleg' DOES is make any connected ground wire NEUTRAL, so any metal cased device would now be energized as part of the circuit (where without the 'cheat' the ground wire connecting would just be isolated or float). Still, a very dangerous situation! 

 

For an RCD or RCBO to 'trip' requires the electrical current on Live/Neutral become unbalanced, usually because the current is partially returning via an alternate route.  And, yes, if you have an RCD and then 'bridge' Neutral to (actual) Ground downstream  then this will potentially wreck havoc with how the RCD functions (usually resulting in constant but predictable nuisance trips).