Getting a tingle off all my metal frame appliances?

[Kenny202]

Have posted on this before but just got a thought. I was actually an electrician in another life but been working in sales last 20 years.

We're renting a place and even though it has earthed outlets I can't see an earth stake outside anywhere except for the hot water. I don't know what they do here, maybe they earth the neutral or something at the pole. Im getting a zap off ALL my metal framed appliances so not just one faulty item. Quite uncomfortable sometimes particularly on my Mac (aluminium) lap top.

My laptop has an Aussie 3 pin plug so I tried an adaptor today that will accept my 3 pins but only has a two pin Thai active and neutral male to plug in. I figured before somehow I am getting a back feed onto the house earth cable (if there is one) making the metal on my appliances live but using a two pin plug today still getting a zap? How when I plug a 2 pin plug in can I be getting a leak onto the aluminium case of my computer? Wouldn't there have to be a current on the earth pin? Can't get my head around it? Be a fairly low voltage coming into the computer from the adapter anyway I imagine?

[Crossy]

If you're getting a tickle of metal framed kit it's not earthed properly, investigate where your ground actually goes.

[bankruatsteve]

The earth/ground is what goes to the round middle pin on a 3 prong plug. If your place has "earthed outlets" then you would have 3-prong receptacles. If your appliances only have 2-pin plugs then you need to add ground wire to the frame and attach to the ground terminal in the outlet.

[Kenny202]

If you're getting a tickle of metal framed kit it's not earthed properly, investigate where your ground actually goes.

I'll have a look behind the breaker box and see if there is an earth in there or maybe it's connected to the neutral in the CB box (MEN?) but even if the house isn't earthed how is the current finding it's way to the case of my computer, and oven, and microwave etc? Only way to the frame of an appliance is through the earth pin which is connected to the frame or a broken wire. If I only have 2 pins in the socket how is the electricity getting tot he frame? I can understand if somehow the earth cable in the home is getting a back feed but if I don't have the earth pin inserted into the socket?

[Crossy]

Many appliances (particularly IT kit) have mains filters, these have capacitors L-E and N-E which make the metalwork float at about 1/2 mains if not grounded, can give a nasty tickle.

Of course if the earth isn't then any filter will indeed feed back to make everything bitey.

Try banging a temporary rod into the garden (a big screwdriver will do) and see if that improves things.

[bankruatsteve]

If you're getting a tickle of metal framed kit it's not earthed properly, investigate where your ground actually goes.

I'll have a look behind the breaker box and see if there is an earth in there or maybe it's connected to the neutral in the CB box (MEN?) but even if the house isn't earthed how is the current finding it's way to the case of my computer, and oven, and microwave etc? Only way to the frame of an appliance is through the earth pin which is connected to the frame or a broken wire. If I only have 2 pins in the socket how is the electricity getting tot he frame? I can understand if somehow the earth cable in the home is getting a back feed but if I don't have the earth pin inserted into the socket?

The live in a unit can leak to a class-1 frame a number of ways: capacitor, dust, mildew, insect activity, etc. If it is properly grounded that leak will carry on to ground and you would not feel the tingle. Earth cables do not get a back-feed from normal distribution.

[lopburi3]

Your oven and microwave will likely have dedicated ground screws for direct ground and strong warnings on item and in manual to make sure they are grounded. If electric is properly grounded and 3 pin plug that should do it - but often sockets even when they appear to have 3 pins will not have a ground attached so it is important to check and if missing attach or run ground from the item direct to a ground point.

Would also recommend RCCD be installed - but that is another subject.

[Crossy]

It may be worth investing in one of these http://www.mea.or.th/minisite/home.php?site=meatech

[chickenslegs]

It may be worth investing in one of these http://www.mea.or.th/minisite/home.php?site=meatech

Are these testers available at any of the usual DIY stores?

[Jim walker]

best bet is try putting in your own earth spike outside in your garden and longer the better

[Crossy]

It may be worth investing in one of these http://www.mea.or.th/minisite/home.php?site=meatech

Are these testers available at any of the usual DIY stores?

Not that I've seen

Several members have reported seeing them at specialist electrical places, but the MEAtech one is the only one I've actually seen in the flesh.

[Kenny202]

If you're getting a tickle of metal framed kit it's not earthed properly, investigate where your ground actually goes.

I'll have a look behind the breaker box and see if there is an earth in there or maybe it's connected to the neutral in the CB box (MEN?) but even if the house isn't earthed how is the current finding it's way to the case of my computer, and oven, and microwave etc? Only way to the frame of an appliance is through the earth pin which is connected to the frame or a broken wire. If I only have 2 pins in the socket how is the electricity getting tot he frame? I can understand if somehow the earth cable in the home is getting a back feed but if I don't have the earth pin inserted into the socket?

The live in a unit can leak to a class-1 frame a number of ways: capacitor, dust, mildew, insect activity, etc. If it is properly grounded that leak will carry on to ground and you would not feel the tingle. Earth cables do not get a back-feed from normal distribution.

All due respect but I'm not only talking IT appliances. Its everything in our home. Microwave, table top oven....anything with a metal frame. I've always had earth leakage breakers in my home (don't in this place) and if I had installed here theyd be tripping instantly. This amount of leakage going to frame can't be normal. Yes I can throw an earth stake in but still can't understand how I'm getting a current to the frames of all my appliances

[Kenny202]

Heres a couple of pics of my box. Looks like a dogs breakfast. All the pale coloured wires I assume are neutrals going to the neutral link on the LH side. Note the green wire attached to the neutral link although this is joined to a white coloured cable so who knows if its an earth link to the neutral or someone ran short of wire. Note also all the green earth cables at the bottom twisted together with a couple of black cables and run up to the link at the top which I assume is the earth link. There is no cable leaving the earth link to a prospective earth stake.

This is a Hiso home in elite estate you would assume built by tradesman (build quality is dreadful)

What do you make of it Crossy?

I cant add the bloody pics? Used the little image icon at the top and added URL from photobucket but says cant use that image extension (JPG?) on this community

[bankruatsteve]

Read Crossy's signature. You have been told and to fix it you need ground wires, via connections, from the frame of your things all the way to a ground rod (or some form of suitable "earth"). Bonding the earth bar to the neutral bar is not a proper ground. Earth leakage detectors (RCD) will not trip from a "tingle" which is far below the 30ma that will knock most people to their ass.

Edit: Go to your post, click edit, then look for Attach Files. Click Choose File and browse for your photos.

[Gonsalviz]

The earth/ground is what goes to the round middle pin on a 3 prong plug. If your place has "earthed outlets" then you would have 3-prong receptacles. If your appliances only have 2-pin plugs then you need to add ground wire to the frame and attach to the ground terminal in the outlet.

I recently had my house wired and told them I wanted everything, with an emphasis on EVERYTHING. Well, I got pretty 3 pin plugs everywhere and a earthing rod that has 1 wire from the breaker box but no earth wires running to the breaker box. Still wondering how that works. Oh wait, I know. It doesn't.

Also there is one thing that you can try. Reverse the plugs in the sockets. Sometimes if the polarity is not correct you will get a tingle. I didn't believe it myself until I tried it.

[Crossy]

All Class-1 appliances leak to some extent, some more than others, older refrigerators and aircons can go leaky, same with electric ovens and rings, they don't actually have to have a mains filter.

It gets worse, because even just a floating ground wire can pick up enough by capacitive coupling from the live wires to give you a significant nip.

A proper ground rod will bleed all this leakage to earth, usually (unless something is seriously wrong) without opening the RCD.

Please check your rod, if you're not sure if you have one, a big screwdriver in the lawn will suffice to check if it helps.

[Snackbar]

There's a habit here of connecting the neutral and earth in the consumer unit. All well if the installation is of a good standard.

Remove the link between the earth and neutral.

Good practice to wear some foot ware or place a rug under your feet when using a portable appliance.

[Kenny202]

There's no link between, not that I can see anyway. It really is a pigs breakfast and not inclined to do anything as it's a rental. The mains box is in the middle of the house and it's a two story house, no way of getting into the lower ceiling and won't be chasing walls etc to get an earth wire outside

[Snackbar]

Ask the landlord to fix it.

Sit back with family sized bag of popcorn.

Ask around for a recommended spark.

[Crossy]

There's a habit here of connecting the neutral and earth in the consumer unit. All well if the installation is of a good standard.

Remove the link between the earth and neutral.

Good practice to wear some foot ware or place a rug under your feet when using a portable appliance.

Ok, Thailand wiring regulations require the system to be TNC-S with MEN for any new installations, you will not get a PEA inspection pass if there is no MEN (N-E) link and a front-end RCD.

That said many, many installations are TT (no MEN link) and also without any earth-leakage protection (front end RCD) and with no functional ground, like our OPs seems to be. These are the ones which will kill you given half a chance.

The general wisdom regarding N-E links is "if there is no MEN link do NOT install one unless you KNOW that MEN is implemented in your area" or "if the is a MEN link do not remove it unless you know that MEN is not implemented in your area and you have a front end RCD and a good ground rod".

As to wearing rubber footwear? Advice is to treat the disease not the symptom. Fix the grounding issue, period!

[TPI]

Know the problem....if you're in an apartment then there is not much you can do! If in a house, loosen a screw in the back of the steel frame of every appliance and connect them all to a length of speaker wire (insulated or un-insulated) run the wire out through your insect screen into the garden, tie or wrap the wire around a metal coat hanger, making sure of a good connection, and bury the coat hanger.

Give your appliance a touch test, no tingle, you're away.......tingle! Pour some water on where you buried the coat hanger and test again!

Your laptop should have a earth point on the chassis somewhere it will look something like this (--IIii)

Oooops! Just realised that you're on the first (second) floor, you only need another 20' of wire, out the window, look for a crack near the wall, tie the wire to a broken(new) hacksaw blade, table knife etc and, with the wire around the knife push it as far as you can into the crack...water if neccessary !

Chok dee

[Crossy]

TPI ^^^, at least use a proper rod (1m will do) and some mains rated wire.

Have you tried the hacksaw blade trick (all mine are painted) and measured the resulting earth?

If you have a balcony railing that will work (remove the paint) as they are invariably welded to the building steel.

[Emster23]

I know indoor custom is barefoot, but not for me. I always wear indoor sandals. I don't want to become the "earth" and then be put into the earth, or temple hibachi.

[duckmandon]

You most likely have a poor neutral conductor. If the house has an MEN (multiple earth neutral) connection then return current is being transferred to the earth wire which is giving you tingles. Do your lights flicker when you turn an appliance on? This can also indicate a bad neutral. Check the connections at the switchboard & if not there it could be at the meter or the connection to the aerials. Hope this helps.

[Snackbar]

Clearly if you are barefoot and perspiring you'll feel the smallest amount of leakage current.

Place a mat, rug, what ever. Problem solved. Period ?

[Crossy]

Clearly if you are barefoot and perspiring you'll feel the smallest amount of leakage current.

Place a mat, rug, what ever. Problem solved. Period ?

NO!

The problem is not 'solved' it is masked.

Further posting of this potentially hazardous advice will be removed without notice, posting holidays are available even in this forum!

[mankondang]

You say your an electrician so I'll use technical terms.

IMHO, Your "neutral is above "earth" potential. I suspect, because you do not have a good earth, possibly none.

Or/Also, because the "star point" in 3 phase generated systems which is normally earthed at the supply/generated end, and is the "neutral" at your end, can cause this if, the 3 phases are unbalanced (excessive current flowing in one or two of three phases compered with third) then you will have current flowing in the "neutral", hence putting it above earth potential. So when you touch a grounded appliance, your in fact connecting to the neutral, and if you also touch true earth, then you are in fact connecting to the "above earth potential/voltage" of the neutral, and the true earth which is at zero voltage. Hence the "tinggle", or little shock.

You say your water heater does not give you a tingle/little shock. So I would suggest you first check you have a good earth at your end. Also then check (you say your an electrician) the voltage between your earth and your neutral.. It should be close to zero, if much higher (enough to give a title) then get the local electrical authority to remedy it, as you/they have an unbalanced load which is significant.

Sorry if I have not explained this well. Best of luck.

[RigPig]

I am not going to read it all as most of it will be rubbish anyway.....

ARE YOU SURE the active and neutral aren't reversed, it's happened twice to me. Being at work, not paid the bill, removed meter. Pay bill install new meter. Go inside house and check polarity . Not gonna happen. Both wires going into the house are black, so I guess a 50/50 chance...

If you have no ground rod and the place is MEN then guess what..... YEP ALL the metal is alive!!!!

Welcome to 200 Baht a day electricians company VERY Limited, schooled at Somchai school of engineering (have selfie with hat), 6th rice paddy on the right, Nakon Nowhere......

Now making BIG money from Farang

[bdenner]

For what ever reason they do not use the MEN (Multiple Earth Neutral) system here (In fact earthing and Thailand is an Oxymoron). You will find that the further you are from the 6.6Kv (or what ever your local HV distribution is) to 220V transformer the higher the Neutral floats - That is the only place the neutral gets EARTHED is at the Star Point of the transformer windings - normally Delta at the primary and Star at the secondary. (Do a Google search)

I'm only 1.5 km from my step down transformer, in the early days my Neutral was up to 75 volts above Earth (I know why! it had to do with the locals "stealing" power by disconnecting their neutral, putting in an Earth, and driving fans, fluos etc between the active and earth = half +/- their power bill!). I installed dual pole CCT breakers because of this.

If you don't have earthing all I can suggest is you turn your 2 pin plug up side down and try that?? Maybe less of a BOOT.

[Crossy]

For what ever reason they do not use the MEN (Multiple Earth Neutral) system here (In fact earthing and Thailand is an Oxymoron).

Actually, as noted earlier, MEN and front-end RCD is a requirement to get a PEA inspection pass for a permanent supply.

This has been the case for at least 10 years, but is largely ignored