Electrical Disaster!

[Emuu]

I moved a couple of months ago into a brand new rental house. Last week when a safety device was being installed, the modified cover for the circuit breaker box nicked the mains cable. Because the box was earthed, but the earth wires were connected to the steel roof joists not the actual earth the whole house went live.

My lady wearing no shoes touched the granite bench and got a belt as the electric hot plate was earthed and earth was now floating at mains voltage.

When I got home, I hade a closer look and discovered that the circuit breakers for power points were 20 amp. which was fair enough, but the smallere wired lighting circuits had 32 amp. breakers on them, about 3 times the size of what the wire could stand. The house could completely burn down and the only ones grinning would be the insurance company, as they wouln't have to pay due to negligence on the part of the builder and/or developer.

In the interim, my lady and I could be dead just from touching a microwave or any other metal appliance.

Can anyone tell me if this is common, and/or, is there any regulatory agency who could/should assess or administer electrical safety in Thailand?

[stroll]

You are lucky they bothered with circuit breakers, rather than welding a nail in place.

And because of the dangers posed by earthing, which you mention above, I reckon they haven't put any earthing in my house (but it is an old one, don't know present regulations), but some wires must have been mixed up somewhere, anyway, after all there are two of them.

After a while you find out which socket is likely to turn your frying pan into a cattleprod and use a different one.

My 50 satang's worth.

[lopburi3]

It is uncommon to have a ground so the person who installed it probably did not have a clue. It is only recently that three wire electric cable became commonly available. Don't believe there is any department concerned. You take care of yourself here.

Obviously you should have the circuit breakers changed (or switch the loads) but as said even having them is a step up for most homes and fire is a very minor concern in cement homes. Make sure the ground is routed to a good ground rod and removed from roof. And, even if you have to pay the cost, get leakage protection (GFI/GFCI/ELB/ELCB or whatever it is called where you are from). A single Safe-T-Cut (local brand name) prior to breakers could protect your whole house for only a couple thousand baht.

[davethailand]

my house is'nt earthed at all, all i have done so far is replaced all sockets and switches with sealed plastic ones, and i've bought a new rcd breaker for the main. eventually i will transfer everything into a consumer unit and earth the cooker, luckily the water is heated via solar panels so the water heating side of it is safe.

I checked the wiring in my club once, although i have a bit of knowledge regarding electrics etc, i replaced the roof panel and left it. there is no way i'm touching any of it.

cowboys.

[Wash]

You should see the mess in rural Thailand if you think the big city stuff with circuit breakers is bad.

A friend added a room for his daughters marriage and asked me to come help him put in a light with a switch. I went to help and before we could complete that simple addition had to redo every wire connection in the house. All were loose connections with arching evident in every connection, and outlet.

All of that pales though when we went to the entrance cable to find that it was broken where it entered the turn off switch and arching was severe and visible during the evenings. They didn't seem afraid of the probable fire hazard with the arching but before leaving we fixed that too.

I suspect this is typical of most of the rural houses you see in all of Thailand and expect that an inspection of all buildings would be one of the most beneficial acts that a government agency could undertake.

I could relate a couple other similar stories but this one is typical of what is up country and the high level of fire risk that virtually all families go to bed with every night. It is amazing to me that there are not fires every night, but the life saving probability is that everyone goes to bed at 8 pm and turns off all the lights and since most houses don't have any appliances it proves to be a life saver.

Amazing Thailand.

[Bluecat]

In the house I was living in before, I had quite a few problems with old aircons.

After a few complains to the landlord, she finally sent an electrician.

First thing he did was checking the wiring.

A puzzled look on his face.

"What's the problem?" I asked him.

"There are three wires, what is the third one for?"

[stroll]

"All of that pales though when we went to the entrance cable to find that it was broken where it entered the turn off switch and arching was severe and visible during the evenings. They didn't seem afraid of the probable fire hazard with the arching but before leaving we fixed that too."

Took the electricians advice and poured a bucket of water to eliminate the arching.

Well, the system is earthed now.

[penzman]

I got some great advice from thaivisa members about electrical wiring. You can check out this post. GUESTHOUSE had some great step by step instructions about ground wires.

http://www.thaivisa.com/forum/index.php?showtopic=8327&hl=

[Darknight]

"regulatory agency who could/should assess or administer electrical safety in Thailand? "

You're kidding right

[Emuu]

Thank you one and all for your input. Particularly the link to the other post that had covered my concerns.

Unfortunately, it just confirms my fears that I will need to do it myself and charge the landlord out of next month's rent!

[davethailand]

a quick question as i am unsure.

my earth leakage breaker melted as the idiot builder did'nt tighten the connection properly, i went out to buy another one but could'nt find one, at the moment there is a siemans rccb 63a rcd on the main (no consumer unit), is that ok.

[thaihome]

You should see the mess in rural Thailand if you think the big city stuff with circuit breakers is bad.

Though I suspect what you state is truer then not, I do have say there is a very good electrician in my wife's (very rural) village.

Having some knowledge (10 year as a licensed electrician in a previous life), I have looked closely at the wiring in the 3 houses in the family "compound". Expecting the worst, I was pleasantly surprised. It was very much up to code, as we used to say.

I have actually seen a breaker trip when the 3rd fan blowing on me was plugged in.

From what I have seen, I think the biggest danger is in the back sub sois of Bangkok. Wasn’t the recent big fire in Suan Plu slum caused by electrical fault?

TH

[lopburi3]

a quick question as i am unsure.

my earth leakage breaker melted as the idiot builder did'nt tighten the connection properly, i went out to buy another one but could'nt find one, at the moment there is a siemans rccb 63a rcd on the main (no consumer unit), is that ok.

It is probably designed for fire protection (if you had a smaller unit downstream)but was unable to find in Google search. You should have a unit with immediate 30mA or less required to trip it to protect yourself. Some units also have a delay which you do not want for personal protection.

If you have an electric store close take what info you have and they can probably look it up for you. Have found some of these folks to be a lot more knowledgeable then those that do the work.

[ChiangmaiJim]

I have read the previous posts and although well meaning, I don't think they have addressed the real issues. My advice to anyone having a house built in Thailand would be to advertise for an electrical technician at least (Farang) and ask him to draw up an electrical plan with cable, breaker sizes etc.

If you have an existing property I would think you need to do the same even more so as the wiring is <deleted>!

I'm thinking that there must be some techs. out there!

There is no quick fix.

I myself have just moved into a new house and basically shot my self in the foot as I assumed all would be safe and satisfactory, its anything but.

My basic problem is that nothing is earthed, and even if you install an RCD device, then there's a good chance it won't work. ie if you have 2 pin sockets in the house, this is because you rely on the earth path to carry the fault current, which causes the out of balance condition within the device, and the resulting trip, and of course 2 pin sockets don't have an earth.

Also someone mentioned earth fault loop impedance, this is simply the the highest path of resistance the fault current has to take on any given circuit, and you want this figure to be as low as possible because you want the breaker to trip as soon as, and if the immpedance is high then the breaker will be slow to operate, and of course if you don't have an earth core there's no path! ie. no trip.

In England everything is bonded down to earth in order to create the path of least resistance, therefore when a fault develops the breaker trips almost immediately.

I know I'm not coming up with any solutions as everyone is going to have adifferent installation, ie. single phase/3 phase incoming supply, and possibly a combination of 2 pin/3 pin sockets, and unless you know what you are doing , leave well alone and get someone who does, you could end up making your installation worse than before.

Best of luck.

[somtaamgaiyang]

Small story.

Two nights ago, faced with what appeared to be a power cut, my wife said that something was burnign outside.

Went outside to see smoke coming from the centre of the road. Bearing in mind that it was hosing down, I ran inside and cut the main breaker. Turns out that the main cable was buried in the road in a PVC pipe at a depth of about 10 cm. As the cars moved over it, eventually the pipe cracked and the wires inside became exposed.

Bearing in mind that the soi floods quite regularly at this time of year it is a miracle that none of us/maid/assorted workers in the mooban haven't died. It was amazing.

[somtaamgaiyang]

How does one find at which point in the circuitry/plugs/system, there is a leak to earth. I have a breaker that continuously trips, and so have set it to direct, which is obviously not the best policy.

Rgds,

STGY

[Up2U]

my house is'nt earthed at all, all i have done so far is replaced all sockets and switches with sealed plastic ones, and i've bought a new rcd breaker for the main. eventually i will transfer everything into a consumer unit and earth the cooker, luckily the water is heated via solar panels so the water heating side of it is safe.

I checked the wiring in my club once, although i have a bit of knowledge regarding electrics etc, i replaced the roof panel and left it. there is no way i'm touching any of it.

cowboys.

Dave,

Within a couple of hundred yards of your club lives a Brit electrician (mainly airports and such). If you want it checked over by a tradesman, I could put you in touch.

[thaihome]

How does one find at which point in the circuitry/plugs/system, there is a leak to earth.  I have a breaker that continuously trips, and so have set it to direct, which is obviously not the best policy.

Rgds,

STGY

First thing would be to replace breaker. You don’t have to buy a new one, just put the circuit on another one in the panel and see if it still trips. If not, go buy a new breaker.

Otherwise, physical examination is the only way to tell exact location. You can narrow it down by disconnecting the various components and test each component with an ohmmeter to see where the short is. Often you are better off just replacing wiring without going through a time consuming troubleshooting effort.

Please be very careful. Safest method is to disconnect power to panel before sticking a screwdriver in it.

TH

[lopburi3]

My basic problem is that nothing is earthed, and even if you install an RCD device, then there's a good chance it won't work. ie if you have 2 pin sockets in the house, this is because you rely on the earth path to carry the fault current, which causes the out of balance condition within the device, and the resulting trip, and of course 2 pin sockets don't have an earth.

False. It checks and trips when there is a difference between the hot and neutral. It does not use or need a ground. It works fine on two wire systems. When the electric finds a path other than the alternating hot/neutral (like through you) it trips.

[lopburi3]

How does one find at which point in the circuitry/plugs/system, there is a leak to earth. I have a breaker that continuously trips, and so have set it to direct, which is obviously not the best policy

If this is intermittent it can take some time. You can have a one time trip caused by your home chinchuk crossing wires in an outlet box. Or you can have a short that is always there. If always trips unplug everything - it still trips buy new unit - if still trips you will have to start looking into outlets/lights and maybe rewire.

If intermittent trips try to isolate time as to using an air-con/water pump/washer/ and if timing matches any unplug for awhile. If only happens during/after rain look for water getting into outside lamps or wires (underground wires never last long here in Bangkok).

This can be a pain so when possible you should design home with RCB located in sub panels rather than using one for all. But it could save your life so worth the trouble.

[somtaamgaiyang]

Many thanks for the info. I will start disconnecting and checking very soon.

Better to be safe than sorry.

Rgds,

STGY

[thaihome]

It checks and trips when there is a difference between the hot and neutral.  It does not use or need a ground.  It works fine on two wire systems.  When the electric finds a path other than the alternating hot/neutral (like through you) it trips.

In 220v systems such as in Thailand, there is normally no neutral, except at the panel. Both legs are "hot" with 220v between them.

Your description is still valid since the devices all operate by sensing the difference in current between the 2 hot legs.

TH

[lopburi3]

In 220v systems such as in Thailand, there is normally no neutral, except at the panel. Both legs are "hot" with 220v between them.

Your description is still valid since the devices all operate by sensing the difference in current between the 2 hot legs.

TH

False. There is a hot and neutral wire. Test it with a meter to ground at any outlet. The hot will be at 230v and the neutral should be at zero.

Believe you are thinking about US 120v systems when the have two hots together to obtain 230v for dryers and such. That is not the system used here.

[thaihome]

Believe you are thinking about US 120v systems when the have two hots together to obtain 230v for dryers and such.  That is not the system used here.

You are right.

That actually explains a couple things that confused me.

TH

[manfromoz]

If anyone in Pattaya area wants there house or club checked let me know. I have aver 20 years experience in the industry and currently run a Company here.

Also, since I assume a lot of people here use computers, etc you want to consider surge protection. Thw local power regulation is terrible, switching makes it worse and lightning strikes account for a major amount of work for computer technicians.