Electrical Vocabulary In Thai

[Sheryl]

Yep I've got the electricity blues again, of the wires cooking, smoking, shorting out type, with my woes much aggravated by the "mai pen rai" assurances of what unfortunately passes for electricians in my area.

Can anyone tell me what a SURGE PROTECTOR is called in Thai? I had one, it fried, would like to replace it (unless it is repairable which I doubt). Nobody locally has a clue about it so I have travelled further afield to the Ampur, doesn't look too promising there either but will give someone who the largest electrical shop swears is actually a trained electrician a whirl.

And when the surge protector fried, one of the wires up in the roof area shorted out as well, knocking out all power. I was away at the time, a local "chang fai" (AKA person with no training in electrical work whatsoever) went in and repaired the short, successful in the sense that power has been restored but I know from bitter experience that the odds are great that he did the repair using wires of too small a capacity which will thus soon overheat and short out again. So when the new "electrician" comes by i need to try to convey this concern to him and get him to go up and check whether the spliced repair wire is in fact of the right gauge ior whatever it's termed.. I know it's ":sai fai" but are there any special words used to convey the idea of a wire's eectrical carrying capacity? (i.e. how do I explain what it is I want him to check - that the spliced in wire repair is the right gauge).?

And lastly what are the terms for CIRCUIT BREAKER, is it just "Brahk-uh"? And the main power supply, is there a term for that or is it just "Main" (doesn't seem to register when I say that)? 2 of the A/cs in the house are not on circuits and I would like to get them on. Need a way to convey that.

Thanks

P.S. I suspect it is a lost cause but if by some miracle any of you know of an actual, qualified electrician in the Sakeo-Kabinburi-Prachinburi-Nakhon Nayok area, maybe even Thanyaburi, please let me know. Anyone who would be willing to come out to Prachin for a comparatively small job. I'll pay extra for the gas/travel time.

[DrTuner]

Take a look at http://www.leonics.co.th/html/th/pd_pqp/surge.php . In my firefox browser I can see the link the mouse pointer is hovering on, products is the second tab on the navigation bar on the top, move your mouse over the items and you'll see from the link what's it about. An easy trick on many Thai websites, since the links are still in English.

[KhunBENQ]

From that website a plausible word for surge protector:

อุปกรณ์ป้องกันไฟกระชาก

A shortened link to thai2english.com including transcription:

http://goo.gl/hEVwQ

Edited May 22, 2012 by KhunBENQ

[Sheryl]

OK I managed to stumble through it with them but now have a host of other questions re the workings of surge protectors.

I had assumed that what I had was something that would trip off the power if a surge came in and that it worked in the fashion of being between the main and the circuit board, with the power first flowing through it (and then either excess power being siphoned off to the ground or else ll the power diverted to ground)

As best as i can understand from discussion with the electricians (he brought along a more seniotr guy who actually did seem tio have soem clue what the devise is), this is not exactly the case. It is attached to the main line before the circuit board but the current does nto flow through it, rather it senses the current volume and creates a short if the current is too high.

Is this correct?

The problem I have with this is that it seems to mean that a Surge Protector can work only once, after which it shorts out (as indeed it did - but I can hardly afford the cost and hassle of replacing these things each time).

Also, when this happened, a short still occurred somewhere after the circuit board (I'm not sure where, one of the wires up in the roof area, may have been the one going to one of the a/cs since the a/c blew out an electric part.) Isn't this exactly what the Surge Protector should have prevented? Or might it be that it wasn't a surge at all but rather a short in a wire (maybe due to a rat nibbling it or whatever) which in turn somehow shorted out the Surge Protyector as well? Would that happen? Does a short somewhere in the system send a surge back down the main wires?

I'm expressing all this badly due to my complete ignorance of these things, if anyone can explain I'll be much obliged. I need to decide whether to replace the Surge Protector with same or similiar device versus something else. (Any suggestions for that will be much appreciated!) I live at the foot of the Khao Yai mountains and get a lot of major thunder storms, lightening etc. Also at the very end of the electrical grid out of the ampur so we get all sorts of lunctuations in power.

[DrTuner]

Take a look at http://en.wikipedia.org/wiki/Surge_protector#Primary_components . There are many types of surge protectors, depending on the used tech they may or may not short circuit for good or blow up upon a large surge.

Maybe it could be combined with a safe-t-cut ? It's a device that cuts off the current if it detects a leak to outside of the intended circuit, such as a wire burning and eventually touching a grounded object. Looks like that company also provides surge protectors, it's the brand I've seen in many houses here.

http://www.safe-t-cut.com/eng/index.php

[bankruatsteve]

SUG protecTOR

[Pib]

OK I managed to stumble through it with them but now have a host of other questions re the workings of surge protectors.

I had assumed that what I had was something that would trip off the power if a surge came in and that it worked in the fashion of being between the main and the circuit board, with the power first flowing through it (and then either excess power being siphoned off to the ground or else ll the power diverted to ground)

As best as i can understand from discussion with the electricians (he brought along a more seniotr guy who actually did seem tio have soem clue what the devise is), this is not exactly the case. It is attached to the main line before the circuit board but the current does nto flow through it, rather it senses the current volume and creates a short if the current is too high.

Is this correct?

The problem I have with this is that it seems to mean that a Surge Protector can work only once, after which it shorts out (as indeed it did - but I can hardly afford the cost and hassle of replacing these things each time).

Also, when this happened, a short still occurred somewhere after the circuit board (I'm not sure where, one of the wires up in the roof area, may have been the one going to one of the a/cs since the a/c blew out an electric part.) Isn't this exactly what the Surge Protector should have prevented? Or might it be that it wasn't a surge at all but rather a short in a wire (maybe due to a rat nibbling it or whatever) which in turn somehow shorted out the Surge Protyector as well? Would that happen? Does a short somewhere in the system send a surge back down the main wires?

I'm expressing all this badly due to my complete ignorance of these things, if anyone can explain I'll be much obliged. I need to decide whether to replace the Surge Protector with same or similiar device versus something else. (Any suggestions for that will be much appreciated!) I live at the foot of the Khao Yai mountains and get a lot of major thunder storms, lightening etc. Also at the very end of the electrical grid out of the ampur so we get all sorts of lunctuations in power.

Most surge protectors are wired in parallel with your home power lines to "sense" the voltage/spikes/surges and when the voltage/spike exceeds a certain level the spike/surge is diverted to Ground/Neutral. There are some in-series surge protectors sold but these are usually for low power situations and not for whole house protectors. Generally, a protector installed at/between the electric meter and your service panel is called a Type I protector, a protector installed in/on your service panel is a Type II protector ( the most common whole house protector), and a protector at the point of use like a power strip is a Type III protector. For the best protection, a Type II protector and Type III protectors should be used based on what I've read....the Type II protector diverts the majority of the surge/spike and the Type III protectors get the remaining surge/spike before it enters your TV, computer, etc.

Now by spike/surge I mean a very short duration one in the "microseconds" ballpark. The core electronic device in practically all surge protectors, be it whole house protectors or surge-protected power strips, is a cheap and simple Metal Oxide Varistor (MOV). Other devices may be used such as gas arrestors (high current capability but slow), but for the most part MOVs with maybe some thermal fuses thrown in are used. Whole house protectors/surge protected power strips are really very simple devices but the manufacturers try to make them sound like rocket science devices in order to justify the usually high price. Usually if you open up a surge protected power strip which you paid a few hundred baht for you will only see one each MOV connected across the Line to Neutral wires....you or me can buy such a MOV for 5 to 10 baht...very low cost little electrical devices they are. The MOV works by rapidly changing it resistance from an open circuit to a short circuit in nanoseconds)...usually in the 25 nanosecond ballpark....when the voltage across it exceeds a certain level. The voltage at where it first begins to conduct is commonly called the Varistor Voltage and when conducting at max/shorted that commonly called the Clamping Voltage. For a MOV used on 220Vrms circuits (i.e., your line approx Thailand 220V line voltage) it's probably going to have a Varistor Voltage of around 450Vpeak (approx 318Vrms) and a Clamping Voltage of around 800Vpeak (565Vrms). This means the MOV starts conducting just a little when a spike reaches 450Vpeak and conducting full stream at 800Vpeak. This also means unless a spike/surge reaches a certain magnitude no protection occurs...the protection only kicks in when the spike/surge gets too high form many electrical applicances/devices to handle, not be immediately damaged by the surge/spike. And to setup the next sentence and for example 20 nanoseconds is 1000 times faster than a 20 microsecond spike.

Whole house surge protectors are usually rated with a KiloAmps (KA) rating in the thousands of KA, usually starting at 10KA and this rating is driven by the rating of the MOVs used within the protector. Now 10KA (10,000 amps) sounds like a lot but remember we are talking a "spike/pulse" in the microseconds ballpark and not "continuous" 50/60Hz voltage/amps that powers our homes. Those KA ratings your see on surge protectors is based on spike-induced on a power line by a lightning strike....an induced spike/surge which averages 8 microseconds from the beginning to the top of the spike/pulse and 20 microseconds from the beginning to the falling mid point of the spike/pulse....and supposedly the largest lightning-induced spike riding power lines into your home is limited to approx 10KA due to a variety of electrical factors, but if a lightning bolt hit your house or power lines just outside your house then you could see much more than 10KA. So, basically you got a fast rise time pulse lasting for 20 microseconds....or said another way, a spike/surge riding on your line voltage that lasted 20 microseconds....but a MOV has no problem reacting fast enough to divert the spike/surge since the MOV is about 1000 times faster at the draw than a lightning spike/pulse.

MOVs in surge protectors can degrade when hit with repeated surges/spikes and they can fail/short out continously/smoke themselves, but this would only occur if a spike exceeded the MOV rating or was hit with repeated large spikes over time...kinda like a boxer getting hit with a knockout punch or just being beat with repeated hard punches. If the MOVs comprising the surge protector have a max, one time KA rating of say 10KA then one 10KA lightning-induced spike could damage your surge protector...but remember, 10KA is the max lightning-induced spike expected at the power line entrance to your residence...not likely to occur....the KA will be something less...probably much less unless you get unlucky as that passing thunderstorm throws down a lightning bolt that hits the electric pole/lines right outside your house or even hits your house. I got unlucky about a year ago when a lighting struck my neighbor's house only a few meters away (blew a hole in the roof) and my ADSL modem, separate router, VOIP box, and a couple of cordless phone power adapters were smoked...actually the lightning appeared to ride in on my phone lines....I've since put some surge arrestors on my phone lines...an I've recently just installed my self-made whole house surge protector. Here's a link to the post talking about it.

When it comes to surge protectors ratings there is still a lot of non-standardization among manufacturers, but the products will/should identify the amount of KA surge it could repeatedly/normally handle (usually around 15-20 medium to large surges) and its max one-time REALLY BIG KA surge it could handle. Take a look at below Safe-T-Cut Surge Protector Module which fits in Safe-T-Cut service panels/boxes..where it says In of 10KA that its normal surge rating...meaning it should handle probably 5-20 such surges of 10KA in size before going to heaven...and where it says Imax of 25KA that is means it could probably handle such a big spike only "once"...and the next large spike may send it to heaven. A whole house protector should also come with lights/signal flags/indicators which identify when the protector has been damaged or failed from a surge...simple enough to build-in and most manufacturers do include such indicators.

And beyond just the KA rating whole house protector/surge protector strips come in different varieties as to what "modes" they can protect...the modes for a single phase wired home being Line to Neutral, Line to Earth, and Neutral to Earth. Surges/spikes from lightning can ride in/be inducted on one, two or all three of your lines (Line, Neutral, Earth). Yeap, don't assume surges/spike only ride the Line/Hot wire. The better/best protectors will protect all three lines/modes; the cheaper protectors will only protect Line to Neutral or Line to Ground.

In closing, remember a surge protector helps protect against spikes/surges of very brief duration in the microseconds ballpark; they do not protect against a scenario where the power line voltage rises to a high valve like 300V (or more) for a few seconds or longer due to a transformer/power line problem...these events may smoke your surge protector along with other stuff in your house...it all depends on what the continuous operating voltage rating is of the MOV(s) within the surge protector which should be at least 250Vrms...preferably 275 to 330Vrms which is what they usually are for a surge protector built for 220V lines.

Enough technical talk...hopefully some of it will be useful. Now, back to working on my Chang Draught.

[Sheryl]

Wow, you certainly know your stuff!

What I had was an LEC brand Type II. I'd had it for a while - probably at least 2 years - so the "multiple hits over time" scenario is certainly possible. Whatever happened, it burned itself straight through the metal casing. Or the other scenario of a sustained high surge could also be.

The "chang" who came by is going to call me back with a quote for a replacement (not necessarily the same brand). He seemed to think the Safe-T-cuts weren't all that good??

I am not so mkuch concerned with protecting specific appliances as I am with avoiding the sudden shorts which knock out the power, invariably at a very inconvenient time (at night/while I'm in the shower) and the risk of electrical fire of which I've already had several near misses. Especially since none of the so-called (and I do mean "so-called" !!) chang fai in the immediate vicinity can remotely be trusted. It takes days and serious money for me to get anything close to an actual electrician to the house, and of course I can't go that long without any power so I end up having the local miscreants in, who in turn invariably do something major wrong (like repairing the short with wiring too thin to manage the load it carries, promptly leading to a second short if not a fire) so I really need to avoid the need for emergency calls. At the same time, I also need a device that will not cause every chang in the province to back away mystified. Years back I had a Leonics and it was a huge pain as no one in the province could handle any problem with it, I always had to wait for them to send someone out from Bkk. Hence my inclination to go with something the current chang recommends on the assumption that if he procures and installs it then he'll understand it and I'll at least have someone within 30 km to call on for problems (he's not local, but based about in the closest town).

I gather from what you say that you think brand is not so important as specs. Can you give me a clearer idea of what specs I should look for? It's a large house with 4 a/cs. 2 of them 20,000 BTUers and often 2 running at once.

[Pib]

Oh, I'm no expert on surge protectors....my electronics background from my military days years & years back combined with some recent reading-up on surge protection has probably just made me dangerous.

When it comes to what whole house surge protector to buy I too wouldn't be to concerned about name brands since all the brands will basically be using mass-produced MOVs inside, but I would try to get one that protects in all three modes of Line (Hot/Live) to Neutral, Line to Protective Earth, and Neutral to Protective Earth. Of course whether your house has a safety/protective earth ground (i.e., that third wire) or not will be a factor in what you choose. Getting a protector which has a In rating of 10-12.5KA and an Imax of 40-50KA should do the job nicely/last a long time. And be sure it is protected by a circuit breaker or fuse so if it ever shorts-out it trips the breaker/blows the fuse which will stop current flow to the protector and hopefully prevent it from catching on fire. You don't want it just hooked/shunted across the line with no over-current protective device like a circuit breaker or fuse. Also be sure it has some built-in lights/signal flags to show when the surge protector is no longer operating properly/has been damaged...like some surge sent it to heaven.

I've attached a presentation I stumbled across today which I think has several slides/pages which does a good job of showing how lightning can enter your home to include through your Ground/Earth connection...so many ways for lightning to get into your home.

And keep in mind and I think you know based on your posts, all the surge/lightning protection in the world isn't going to prevent damage being caused by power company/electrical service/wiring problems (i.e., like your line voltage going significantly above 220V for X-amount of time or something mis-wired). Your recently departed surge protector may have experienced that kind of death versus being slowly degraded by repeated surges until it just said I'm shorting out. Cheers.

Thomas&Betts_Furse Surge Protection Presentation.pdf

[Sheryl]

Thanks a lot, this was very helpful

[luudee]

Pib, great write up, thanks !

I built a Type I surge protector myself some 6 years ago. Our power line got hit bu lightning a few times, and it

was not pretty. I installed it where the power lines enter the house.

I got a bunch of MOV from DigiKey (mail-order), and as you suggested I chose the 430V peak type, 25KA, connected

two in parallel, just in case ... no problems since ! There is a large thermal fuse in front of them, never had it trip, but

also never ahd another spike make it through.

Cheers,

rudi

[Sheryl]

For those of us who don't have the know how to do the above -- can anyone advise me of a shop selling surge protectors in either the Nakhon Nayok - Kabinburi - Chachengsao area, the pinklao-Taling Chan part of Bangkok (anywhere between Pinklao and Nakhorn Pathom) or failing that, in Bangkok? I have verified that whole house surge protectors are not are not sold anywhere in Prachinburi. Have found a fairly credible electrician to install the thing but need to buy it first. (He offered to just repair the old one but after seeing the thoroughly charred and very worn looking innards of it, I think maybe not a great idea. plus what I had was 40 K, I'm hoping a 50 K will last longer).

Thanks!

[Crossy]

Before investing in an exotic surge arrestor it sounds like you need to get your whole place properly re-wired to make it safe from fire and shock.

Only then is it sensible to start looking at whole house surge protection, how much kit do you have that needs protection (TV, PC and other technology)? You may be better off getting individual high quality protectors for delicate appliances.

Our latest sparks is very good, unfortunately I think you're too far out for him to consider travelling

Do you have photos of the dead unit, just so we can be sure we are actually talking about the same device, my whole house arrestors are barely bigger than a regular breaker?

[electau]

If you install SPDs on the main switch board they should be installed between the main switch and the line side of any RCD. They should be protected by an MCB. This will give you primary protection. Additional protection may be afforded by the use of surge protected power boards for individual equipment. You will require a compliant earthing system with PE conductors and main earth and electrode.

DIN rail mounting devices are available with a red/green indicator 40A per phase, 8/20 micro sec impluse and 275VAC. For installation in exposed locations eg long aerial lines, high lightning areas it may be prudent to install 100kA per phase units.

One for each phase for a MEN installation and one for each phase and neutral for a TT installation.

[Sheryl]

Crossy - I already had the house completely rewired, as well as grounded (a little detail the original contractor omitted!) at great expense so do not want to repeat it. Plus god knows where I'd find a reliable sparky to do it, last one was located with great difficulty and came from Bkk.

The Surge Protector I had is indeed not much larger than a breaker, pic attached. Also attach pics of what its innards look like now, as you can see, very fried. In retrospect I realize i have had it for maybe 10 years so this may be the cumulative toll of 10 years of surges. The electrical current out here is very unstable even when not hit by lightening which the local lines very, very often are.

As I mentioned earlier I am not primarily concerned with protecting individual appliances (though it would be nice not to have the a/cs shorted out). I want to prevent what are otherwise frequent short-outs resulting in loss of power, usually at night when I can't get anyone but the local charlatans to come in who then proceed to fix the short with wires of insufficient carrying load leading to melting wires, fire etc etc you get it.

I live right at the foot of Khao Yai and we get spectacular thunderstorms almost daily more than 6 months of the year . Lightening strikes in the area are very common, happens at least once a year in my immediate vicinity (knock on wood never directly my house, but nearby trees, poles and a pagoda). I think I really do needs a whole house surge protector. i used to have a high end voltage stabilized from Leonics and it constantly blew out from surges, was advised at that time by Leonics to put in the Surge Protector. Eventually decided no need for the stabilizer and switched to only the Surge Protector after the last time the Stabilizer conked out. .

Electau - I'm afraid much of what you said is Greek to me. I assume SPD means Surge Protection Device but have no clue as to what RCD, MCB and TT are??? I gather DIN is some sort of metal bracket that the circuit board is on? These DIN rail clip ons you recommend -- are they available in Thailand and if so where? I am finding it hard to source even a Surge Protector here...

The Surge Protectors I had was encased in a metal enclosure box (in addition of course to its own metal casing) and mounted at the main circuit board. And I had the house grounded some years back. That's as much as I can tell you.

[prefabs]

Crossy - I already had the house completely rewired, as well as grounded (a little detail the original contractor omitted!) at great expense so do not want to repeat it. Plus god knows where I'd find a reliable sparky to do it, last one was located with great difficulty and came from Bkk.

The Surge Protector I had is indeed not much larger than a breaker, pic attached. Also attach pics of what its innards look like now, as you can see, very fried. In retrospect I realize i have had it for maybe 10 years so this may be the cumulative toll of 10 years of surges. The electrical current out here is very unstable even when not hit by lightening which the local lines very, very often are.

As I mentioned earlier I am not primarily concerned with protecting individual appliances (though it would be nice not to have the a/cs shorted out). I want to prevent what are otherwise frequent short-outs resulting in loss of power, usually at night when I can't get anyone but the local charlatans to come in who then proceed to fix the short with wires of insufficient carrying load leading to melting wires, fire etc etc you get it.

I live right at the foot of Khao Yai and we get spectacular thunderstorms almost daily more than 6 months of the year . Lightening strikes in the area are very common, happens at least once a year in my immediate vicinity (knock on wood never directly my house, but nearby trees, poles and a pagoda). I think I really do needs a whole house surge protector. i used to have a high end voltage stabilized from Leonics and it constantly blew out from surges, was advised at that time by Leonics to put in the Surge Protector. Eventually decided no need for the stabilizer and switched to only the Surge Protector after the last time the Stabilizer conked out. .

Electau - I'm afraid much of what you said is Greek to me. I assume SPD means Surge Protection Device but have no clue as to what RCD, MCB and TT are??? I gather DIN is some sort of metal bracket that the circuit board is on? These DIN rail clip ons you recommend -- are they available in Thailand and if so where? I am finding it hard to source even a Surge Protector here...

The Surge Protectors I had was encased in a metal enclosure box (in addition of course to its own metal casing) and mounted at the main circuit board. And I had the house grounded some years back. That's as much as I can tell you.

The device in post #7 fits on to a DIN Rail

[Pib]

Wow!!! Since you are pretty sure your wiring is good and since you live in a lightning-rich area those pictures of those blown/split/burnt varistors (MOVs) and other components sure looks like pictures of other surge protector which people say went to heaven during a thunderstorm. I bet those varistors that are split were the first ones to fail....hopefully gave up their lifes in stopping a lightning surge....then some people may say I rathter risk a lightnting surge taking out some of my electronics/electrical equipment versus the possibility of hte surge arrestor catching on fire. If it ain't one risk it's another risk.

Hurts my head too with all the electrical systems acronyms...especially when I first started reading up on electrical systems/earthing. The MEN (Multiple Earth Neutral) and TT acronyms basically describe the "the type of earthing system" used. That is, where the Neutral is earthed, whether it's hooked-up and/or bonded to the Protective Earth/Safety Earth, etc., since both of these wires (Neutral and Protective Earth) are hooked to earth "at some point/multiple points" from the power source. But "where and if" they are connected and other factors makes the difference in what the electrical/earthing system is named. Take a look at this wikipedia article for more info on electrical/earthing systems...it may help a little...it helped me a little while also hurting my head some more.

If your house is like mine and how power lines are fed around the moobaan (and some other moobaans I looked at) , I expect/guess you have a TT earthing system which means your have 2 wires, a Phase (a.k.a., hot, line, live, etc) and Neutral wire, feeding power to your home/into your main circuit box. Now you may see four wires on the electric poles which is Phase 1, Phase 2, Phase 3, and Neutral, but for a Single Phase powered house your house is only hooked to 1 of the 3 Phase wires which carry 220 volts (could be any of the three wires as to balance the load the electric company will hook approx 1/3 of the homes on Phase 1, 1/3 of the homes on Phase 2, and 1/3 of the homes on Phase 3...and then the second wire leading to your house is the Neutral wire. From what I've seen the Neutral wire will be top wire on the 4 wires on the pole...of course this assumes your area has 3 phase power feeding to it....many areas just have one phase (two wires) feeding the moobaan/soi.

The Phase wire hooks to/runs through your individual circuit breakers and all your neutral wires hook to a Neutral bar within the main circuit box. And if, repeat, if you have 3 wire wiring in your house (i.e., Phase, Neutral, and Protective Earth), all the Protective Earth (Safety Earth) wires (hopefully green/green-yellow stripped in color) are hooked to a Earthing bar that is "not" connected to your Neutral bar for a TT system. Instead the Earthing bar has a heavy gauge wire (around 10sqmm) running from it to a spike/rebar in the ground/foundation. But in the Thailand which is the Land of Electrical Surprises you could have something different.

Below is a picture of a TT system. If your have Three Phase power to your house (i.e., four wires feeding into your circuit box) then look at the left-middle side of the image; if you have Single Phase power to your house (i.e, two wires feeding into your circuit box) then look at the right side of the image. And on the far left of the image you see something labeled Source of Energy which would normally be considered the transformer feeding your area. And if you walk down to that transformer feeding the power lines to your house you should see two bare wires leading down the transformer concrete pole(s) to earth....one of those wires will be hooked to the Neutral wire feeding homes (probably the top wire) and the other wire will hooked to the case of the transformer which is basically acting like a Protective/Safety Earth. Or at least that is what I've seen in my large moobaan and other moobaans for single family type houses.

And all the different electrical/earthing systems have different peculiarities about them which seem to drive different variations by some countries and different manufacturers of the recommended/optimum surge protector. Attached article focuses on the TT Earthing system which I'm "guessing" you have. Just FYI. Or maybe I did this just to make your head hurt a little more.

I wish I could give you some info on where to find a whole house surge protector like you are looking for but all I've seen in Thailand are the DIN mounted type....the type that kinda look like circuit breakers and install in you main circuit box. But then you gotta find the kind that will fit your particular main circuit box of which there are many varieties. Good luck.

Edited May 30, 2012 by Pib

[Pib]

And all the different electrical/earthing systems have different peculiarities about them which seem to drive different variations by some countries and different manufacturers of the recommended/optimum surge protector. Attached article focuses on the TT Earthing system which I'm "guessing" you have. Just FYI. Or maybe I did this just to make your head hurt a little more.

Whoops...forgot to attach the article...the wife was rushing me to go walk the dogs before it rained...here it is.

And regarding those DIN mounted surge protector modules that go in your main circuit box, if you are like me all of my 16 branch circuit slots are full with circuit breakers/RCBOs....I would have to remove circuit breakers/RCBOs to make room for surge protection modules or install a separate or larger main circuit box if I could even find any for Square D surge protector modules in Thailand...heck, for a while I had a hard enough time finding some Square D RCBOs for the main circuit box/water heaters....really wanted 30ma RCBOs but could only find 10ma RCBOs. So for me, the separate from the main box surge protector is pretty much the only way to quickly and easily add whole house surge protection. Plus with the separate whole house protector a person can usually get a higher KiloAmp surge rating...I guess it may also prevent your main box from getting damaged by surge protector/module smoking itself...I think I would rather have a surge protector smoke itself in its own, standalone box. But no doubt, I expect there are plenty of pro's and con's for different types of surge protector and whether surge protection is even needed. But for me and the thunderstorms I experience each each year along with the year round brief power on-offs as the power company balances loads around the area, I'll signup for whole house surge protection.

Things Worth Knowing About Surge Protection.pdf

[Crossy]

That arrestor is well fried.

It should never have ended up that bad unless from a direct strike, was it protected by its own MCB?

[bankruatsteve]

And again... MCB = circuit breaker (don't know why it's called miniature 'cause it's not).

[Sheryl]

The device in post #7 fits on to a DIN Rail

According to the Safe-T-Cut people they no longer make it/sell it in Thailand

After exhaustive searching the only SPD I could find is Leonics, same as the one that I had that fried, and I had to go to their head office to buy it as they say they haven't supplied it to any retail outlets.

[Sheryl]

That arrestor is well fried.

It should never have ended up that bad unless from a direct strike, was it protected by its own MCB?

Yes , it was. That is, it was on its own circuit breaker which is one of the many breakers in the main panel. it was not on its own panel. Now it is possible that this is exactly what shorted out. Somewhere up in the roof there was wiring that had shorted, I have no idea to what but would guess the SPD. Other possibility would be one of the a/cs which after this even was on the blink with a part of the compressor damaged. While I had most of the wiring encased in PVC pipes to protect against shorts due to critters nibbling the wires i think (nto sure) the SPD was installed after that and thus likely not so encased.

If the wiring to the SPD (not the main witing but the wore that powers it) were to short out from something like that, would it send a big surge into the device/

the other thing is that I had the device for many years so the damage seen may be from not one but many repeated surges.

there were speatacular thunderstorms in the area when all this happened.

[David006]

...before the advent of thyristors/thermistors etc. there was a thing called a "carbon protector" ....basically a couple of blocks of carbon one grounded with an air gap for the surge to jump as in lightning strikes.

Was used in telecom applications when wires were open on poles and hector was a pup ....sometimes wonder that some of the older solutions were not ......well..better?

[Sheryl]

Pib,

Thanks again for the detailed info, though can't say I follow all of it, but I did follow so,me.

The SPD was in its own stand alone metal enclosure box located near the circuit panel. And as this is the only type I have been able to source,. I will be replacing it with same. The external metal enclosure didn't burn through, just the device itself (to a crisp, as you've seen),

I have single phase, not 3 phase. Below are pix of what the wires look like coming onto the house. If anything strikes you as amiss please advise.

When the house was initially wired, it was not grounded at all and AFAIK none of the houses in the area are grounded, locals (inc all the "electricians") thought it was a crazy farang idea. It took me a few years and endless go-rounds with the so-called chang fai telling me that it was perfectly normally to get shocks from all the appliances etc to figure this out. At which time I had a good quality (I think - sure cost enough) ground put in by a firm from Bangkok. So there is now a ground wire coming from the main circuit panel area to a grounding rod but I doubt there is a ground wire among the wires coming into the house initially as that just does not seem to be the practice out here.

So as it now stands, I have obtained a replacement SPD of the exact same brand and model as the one that fried (40 KVA - they didn't have anything higher) and unless anyone thinks it's unwise, I will have it installed in the existing place

[Sheryl]

P.S. This is what the grounding looks like (couldn't fit any more uploads in the above post):

1) coming out at the bottom from wires below the main circuit panel

2) other side of the wall, outside (black stuff is some sort of insulating goo the electrician applied, not burnt soot)

3) a little further along outside

4) wire into ground

[Pib]

Sheryl,

It's hard telling what fried the surge protector...it could have just died of old age. From my looking around it seems to be very hard to find separate whole house protectors in Thailand. I know I sure haven't seen any at hardware stores like HomePro, Global, HomeWorks, etc. Now these stores do care some main circuit boxes that come with "one each" single pole surge protector module (kinda looks like a circuit breaker) which is probably hooked up from Line to Earth to provide one mode of sure protection versus two or three modes of protection. That is, Line to Earth, Neutral to Earth, and Line to Neutral.

Just today I was at the Global in Nakhon Pathom which has a electrical section which makes the electrical section at HomePro's/Homeworks look sad and small. Now, Global didn't have any separate whole house protectors but they did have several main circuit boxes by different manufacturers that came fully outfitted with circuit breakers, RCD, and one-each surge protector module. I asked the sales rep if they had replacement surge modules in case one went bad...she said no...would have to maybe special order or contact the manufacturer directly. And as mentioned, they didn't have any separate whole house surge protectors.

I know what you mean about the electrical service/wiring you describe in your post 24. The reason I was in Nakhon Pathom today was to really let the wife visit her mom while I went to the nearby Global to kill time. But where my wife's mom lives it's basically the land of two electrical wires also....a Line and Neutral line feeding the the main service box with no safety ground/spikes...the whole house is just wired with 2 wires/2 wire outlets...seems to be pretty much the norm out in the provinces for older houses and even common in many parts of big cities like of Bangkok. Surge protection, RCD protection, safety ground/earth spike, and 3-wire wiring inside the home is just some of that stuff farangs seem to be concerned about/want to have.....or some of that new electrical wiring being built into new homes.

Yeap, Thailand is definitely the Land of Electrical Surprises. Wishing your replacement surge protector a long life.

Cheers,

Pib

Edited June 3, 2012 by Pib

[DrTuner]

I don't have actual experience with the SPDs as I come from electronics background, but wouldn't it make sense to use multiple devices parallel and closely coupled by heavy gauge wire if there are a lot of high energy spikes in the net ?

[electau]

Sheryl.

SPD stands for surge protection device.

MCB is minature circuit breaker, these are a small frame size with fixed overcurrent setting, 100A or less, DIN rail mounting, plug in or clip -in on a plate.

DIN Euro type rail mounting for equipment. It is an IEC standard.

RCD stands for any residual current device. US term is ground fault circuit interrupter GFCI.

10ma and 30ma are standard IEC ratings.

RCCD is the above with residual current protection only.ie 30ma.

RCBO is the above with residual current and overcurrent protection. ie 30ma/20A. A combination RCD/MCB.

MEN. multiple earthed neutral system. The incoming neutral IS bonded to the electrical installation earthing system at the main switchboard.

TT the main incoming neutral conductor is NOT bonded to the electrical installation earthing system at the main switchboard. The earthing system is direct.

The surge protector may have been destroyed because it was protected by an overcurrent protective device that was too large a rating ie the MCB. An SPD should be protected by an MCB in the line conductor only and the earthed side of the SPD must be connected to the earth bar or main earth with a conductor green or green /yellow of 4sqmm minimum. If the SPD short circuits the MCB operates. The SPD is then checked then replaced. you leave the MCB in the off position until the SPD is replaced.

The SPDs should be located in the switch board with the connection from the MCB to the SPD as short as possible. The MCB need not be larger than 32A.

As far a lightning protection and the connection of SPDs are concerned the MEN system is the preferred connection. But this may not be available in your area.

[Crossy]

I don't have actual experience with the SPDs as I come from electronics background, but wouldn't it make sense to use multiple devices parallel and closely coupled by heavy gauge wire if there are a lot of high energy spikes in the net ?

As I do more research into SPD's the water muddies considerably.

As well as several different configurations on thing I have learned is that as a MOV type SPD wears (from suppressing surges) its trigger voltage goes down until, eventually, it becomes lower than the peak supply voltage at which time it triggers permanently and blows open or fails short (which is why it needs an MCB).

If you parallel devices each will need its own MCB in order to maintain protection when the weakest device fails.

[Pib]

Here’s a document from the ABB company, specifically the ABB Lightning Protection Group, which I stumbled across yesterday while doing more surge protection googling. I’m really glad I stumbled across this document because for me it really helped to tie-together/clarify some surge protection and hookup questions I had in my Chang beer damaged brain. Layman’s language is used—or at least fairly layman on this technical subject, and plenty of pictures along with explanation of acronyms/terminology used.

Pages 2 thru 4 talks general points on lightning and its risks, causes of transient overage/spikes/surges, etc., but also talks a little about equipment/man made induced surges like from motors, A/Cs., appliances, equipment, etc., turning off and on which can cause premature ageing and breakdown to use some of the documents own words....and of course we know what lightning can do to electricial equipment and is also a great tree splitter.

Pages 6 thru 8 talks different type of surge protection, although the pages concentrate the discussion on Type I and II surge protection which is the type installed in main and sub circuit panels. Type III surge protectors also exist like surge-protected power strips where you may plug-in your electrical items in….like your TV, TV setup boxes, stereo, DVD player, modem, router, and other electrical appliances. And a Type I protector is really nothing more than a whole house protector which can come in circuit breaker shaped modules that plug into your circuit breaker box slots or be a device you mount/connect just outside (or even inside for a large service panel) the main circuit box/panel with the protector wired to the main box/lines. Always be sure to wire the protector up in accordance with the manufacturer's instructions which will probably require it being protected by/hooked up to an over-current device such as a circuit breaker. It also goes into Terminology used when talking about surge suppressors, surge/current/voltage ratings, protection modes, etc. On page 8 there is even a world map showing lightning strike density expressed as the number of lightning strikes per square kilometer per year. The map appears to show parts of Thailand in the heaviest density zone—I sure didn’t need this map to tell me that but at least it helps confirm.

Pages 10 thru 13 talks the different Earthing systems (ie., TT, TN, TNS, IT)…it also talks different surge protection modes since surges can occur between L-L (Line to Line on a three phase system), Line to Earth (L-E), Line to Neutral (L-N) and even Neutral to Earth (N-E). And on page 12 I think it does a good job (for me at least) putting into a picture why having three modes of protection (L-E, L-N, & N-E) on a single phase system like I think most people have is better than just one or two modes of protection which usually connect only between L-E, L-E & N-E, or L-E & L-N depending on the particular surge protector you have. Manufacturers build different surge protector modules for main boxes and internally these different modules can be wired differently, quite possibly protecting in three modes on a single phase system (or even four modes for a 3 phase system).

A 2-pole surge protector module (or even protector you hookup outside the circuit box) may show you hook it up by connecting one wire to L on the top of the module, one wire to N on the top, and one wire to E (a.k.a., PE) on the bottom of the module…a person could wrongly assume that surge protector only provides surge protection from L-E and N-E---and well it could depending on its internal design…but when looking at the internal “schematic” if provided by the manufacturer or deduced from the manufacturer’s specifications the schematic/specs could show it’s actually also putting a surge arrestor device (i.e., varistor, gas discharge tube, spark arrestor---but most probably a varistor) also across L-N to provide three modes of protection on a single phase system.

And since the TT earthing system is very common in Thailand (it’s what I have here in my western Bangkok home which is 5 years old with internal 3 wire wiring) on page 11 there is a image which says surges/overvoltage can also occur between L (a.k.a., Phase) and N…and of course a surge could also occur between L to E and N to E. It even says for a TNS system surges/overvoltages can occur between L and N depending on the lengths of the Neutral cable and earth/protective earth (PE) cable. When it comes to lightning and the extremely high voltage levels involved, direct lightning strikes or lightning induced surges can result in many paths being found into your home….even up through the earth ground. And for a 1 pole surge protector module it’s hookup is going to be L to N/E, which will provide one (maybe two) modes of protection depending on the earthing system you have.

Page 14- 16 talks about considerations/characteristics in choosing a surge protector…once again plenty of pictures to help in the understanding.

Lot of more good info in the document which is 54 pages long although the later pages get into schematics, connection diagrams, and specifications which will probably caused most people eyes to be glazed over. But for those of you out there it may provide additional info and answers you’ve been looking for. I know for me the parts of the this document which actually showed internal schematics along with connection/hookup diagrams clarified for me that three modes of protection for TT system is needed/a good thing and just looking at the outside of a surge protector module/how it's hooked up could very well not be indicative of what lines (i.e., L, N, and E) and being connected inside the protector through a surge arrestor device (e.g., varistor) and in turn providing various modes of surge protecton.. I think page 26 is a good example of this.

Ok, I’m glazing my own eyes over in writing this….is it too early for a Chang beer? Please see attached document for what I consider some good surge protection info at the layman and technical levels. Cheers.

ABB Overvoltage Protection.pdf