Thanks Crossy

[TongueThaied]

It is high time I gave a big public thanks to Crossy, the famous GB electrician, for his invaluable contribution of his Thai house wiring site: http://www.crossy.co.uk/wiring/

I fully understand electricity, and even built a few spec homes in the US many years ago. I have done a lot of DIY wiring (correctly), but I am no electrician. When it comes to understanding the difference between types of circuit breakers, the best set-up for ELCB protection or calculating the proper wire sizes for long cable runs, I have to do a little research. Crossy's site seems to pretty much cover the waterfront. During the five years I have been in Thailand, I have turned to this valuable resource time and time again.

I have never seen any advertising on his site so it all seems to be from the goodness of his heart. So, Crossy, thanks a million!

Here, I will include one little jewel I discovered on Crossy's site some five years ago. It is something useful to the expat who thinks he already knows everything there is to know about electricity in Thailand. We all use those plug strips from time to time, right? The first thing i did after arriving in Thailand was install a ground rod at my rented house and install a few grounded outlets. Of course, I made sure the polarity was correct, and while I was about it, corrected polarity throughout the house, which was, not surprisingly, wrong in about 50% of cases. So all set. Had my grounded outlet with correct polarity, plugged in my three-prong (grounded) plug strip (one of the more expensive models purchased in Thailand) and hooked up all my computer stuff.

Some six months later, I discovered Crossy's site and was cruising through it and came upon a section about these plug strips. He said that the plug strips sold in Thailand were often miswired, with polarity reversed and, sometimes the ground prong on the plug was not even connected to the ground receptacle hole on the strip. I knew I had a good one, since it was one of the pricier models, but just for kicks and giggles I pulled out my volt/ohm meter and tested it. Imaging my chagrin (actually, I was pissed!) when I discovered that this strip BOTH had the polarity reversed and NO ground. The third prong on the plug was only for show. I could correct the polarity, but there was no ground wire visible to hook up inside the strip. The only thing I could do was replace the entire cord.

I went shopping for a new grounded plug strip, tester in hand. I boldly opened up dozens of packages and tested them, while clerks looked on. I went to at least three different stores including Tesco Lotus and Big C. Incredibly, over 80% of the units I tested were miswired. It appears that the assembly people in the factories just hook it all up randomly.

Who would ever have guessed, or even thought about it? Coming from the US, where lawyers keep us all safe, it simply never occurred to me that these things would be miswired. Thanks again, Crossy!

[electau]

With your reference to power boards or power strips the polarity is normally in Thailand looking at the socket outlet in a clockwise direction is E, N, L. This complies with Thai Industrial Standards and the NEC standard.

Yes, the earth terminal may not have a earth conductor connected at the terminal. They often have only a 2 pin plug top and 2 core lead.

In all cases if a switch is fitted as an integral part of the power board it must operate in the L conductor.

IEC, British standards and AS3112 the polarity is E, L, N. In this case the standard requires that the power board is fitted with a 3 core lead and 3 pin plug top, with the earth conductor connected to the earth terminal.

You do not rewire power boards, you replace them.

Reversal of polarity at a socket outlet is not a safety issue providing the L conductor is switched.

Removing the plug top from the socket outlet complies with the switching requirement (in Thailand).

[Crossy]

Don't forget we have other Sparkies who post regularly, Electau is our current resident Aussie and we should not forget Elkangorito (sadly no longer on the board).

[ravip]

Thank you very much indeed, Crossy. Very useful, informative, practical and easily understood website.

[JAS21]

Yes, great info Crossy ... by the way how is the wiring in your new house? .....

[Crossy]

JAS, you know full well the shower of **** that our wiring turned in to whilst I was out of the country

Sorted now after Sparkie No4 fixed the ceiling fan.

[TongueThaied]

Oh man, Crossy, you, of all people, left the country while your house was being wired? I had you pegged as the electrical god. Now you've sunk to expert, but mortal!

As for rewiring a electrical strip to correct polarity and connecting a ground, of course you can. Why not? Anybody that knows how and can solder is perfectly capable of doing this -- and doing it better than they could do it at the factory, apparently. I do a lot of rewiring of things here. Sometimes its because rats have chewed up the original wires. Sometimes it's the only alternative. The plug strips I rewired had a three pin plug and a three hole receptacle, but only a two core lead, which is what I replaced. A bit of a scam, those things.

I also have a 110V Makita lithium ion battery, model DC18RA, that I converted to 220V for use in LOS. I am not sure why, but the 110V version can be had for $30-40, while the 220V version goes for $100+. I converted two of them and the conversion took about a nickel's worth of electronic parts. Since the plug is designed to assure correct polarity, I always make sure it gets it. Has worked great through hundreds of recharges over three years.

Not knowing what the Thai standard is, being American, I have wired everything to the NEC standard, so I got lucky with the Thai standard. Funny, the British standard is different. Hmmm, they drive on the wrong side of the road, too. (-:

[Pib]

With your reference to power boards or power strips the polarity is normally in Thailand looking at the socket outlet in a clockwise direction is E, N, L. This complies with Thai Industrial Standards and the NEC standard.

Yes, the earth terminal may not have a earth conductor connected at the terminal. They often have only a 2 pin plug top and 2 core lead.

In all cases if a switch is fitted as an integral part of the power board it must operate in the L conductor.

IEC, British standards and AS3112 the polarity is E, L, N. In this case the standard requires that the power board is fitted with a 3 core lead and 3 pin plug top, with the earth conductor connected to the earth terminal.

You do not rewire power boards, you replace them.

Reversal of polarity at a socket outlet is not a safety issue providing the L conductor is switched.

Removing the plug top from the socket outlet complies with the switching requirement (in Thailand).

Thanks...good info.

Most of the 3 wire/plug power strips I've seen/bought in Thailand come wired/marked IAW with the British Standards/AS3112 as mentioned above...most have been made in China. That is, when looking at a power strip outlet with the E at 12 o'clock, the L is at 3 o'clock and the N at 9 o'clock. However, most of the 3 wire/plug wall outlets I've bought are marked with the E at 12, L at 9 and N at 3 o'clock. But the Safe-T-Cut GFCI/RCD wall outlets were wired E at 12, L at 3, and N at 9 o'clock.

I opened up most of the power strips to install/replace MOV surge protection across all three lines for three modes of surge protection....and in many cases if I wanted to rewire the L & N polarity it would not have been an easy or quick job especially if I wanted to keep the circuit breaker/fuse & switch in the high/hot side of the line for safety purposes. And in some cases it really wasn't possible to rewire if I wanted to keep the fuse and switch in the high side of the line...and even ensure the high/hot side went to the fuse holder rear connector. It's important to power to a switch/fuse/breaker in the high/hot side of the line to ensure power can be killed or force the CB/fuse to blow if there is an internal short/fault on a device which allows current flow via Earth versus Neutral (assuming you have a 3 wire setup)...with a fault to Earth but the CB/fuse/switch being in the Neutral line the item could remain powered up with current flow from Earth to Hot/Live..plus also making the case of the item a shocking hazard.

For "polarity" purposes I really don't worry if the L & N are reversed since the three slot outlets almost always (let's say 80 to 90% of the time) have a two prong device being plugged into the strip (i.e., no Earth 3rd wire)...and whether the strip's L & N connections are wired correctly/in accordance with standard XYZ when plugging in a two prong/non polarized/non earthed plug which I can plug in two different ways with a mere 180 degree rotation (i.e., flip polarity) is the predominate plug on devices like TVs, stereos, DVD, TV set-top boxes, modem/routers, rice cookers, microwaves, fans, electric shavers, electric hair clippers, and many-many other devices....for these devices the L & N polarity on a power strip or wall outlet is really a non-issue. And then most of our two wire plug in devices now days are contained within plastic/non-conductive cases which greatly reduces the chance of an internal Hot to equipment case fault causing a shocking hazard....plus most of these devices will not have an external fuse holder (or CB) to potentially cause a shocking hazard if wired incorrectly (i.e., Hot wire not wired to rear of fuse connector) when removing a fuse with the device still plugged in.

With so many different electrical standards in the world for building wiring and equipment wiring it's almost like we don't really have "a standard." Throw in all the two wire devices we have in our home and work place today, it's almost like having a Earth wire or even being concerned about polarization is becoming a non-issue. But with that being said, whenever possible to have a 3 wire connection "with that Safety Important Earth wire" it's definitely the safe way to go....and I definitely try to wire my home in accordance with as "few" electrical standards as possible/safe. My goal is to ensure an Earth wire whenever possible (but most devices now days as mentioned above come without an earth wire--just two wire...and also ensure I standardize my wall outlets L & N polarity even if my two wire devices could care less about polarity).

Edited August 9, 2012 by Pib

[Crossy]

Oh man, Crossy, you, of all people, left the country while your house was being wired? I had you pegged as the electrical god. Now you've sunk to expert, but mortal!

Not knowing what the Thai standard is, being American, I have wired everything to the NEC standard, so I got lucky with the Thai standard. Funny, the British standard is different. Hmmm, they drive on the wrong side of the road, too. (-:

Sheer bad luck that was, but earning money is quite high on my list of important activities. The problem was chiefly that our initial sparks, whilst pretty good, was a piss-head and got his 'brother' to run the cables. Brother is not a sparks and decided that rather than running a single piece from DB to outlet he took the easy option of running about 4 bits per run, his joints were carp even using the 'foolproof' Wago connectors I gave him.

The Thai standard is broadly based on the NEC, you hit pay-dirt there