Thai Domestic Electrical Work.

[dotcom]

The best I can work out the hated "Shuko" plugs have no provision for polarity. I have a set of wire cutters I use to install "Shuko" plugs.

You'd think the Dutch Germans & French would have more sense.

[longball53098]

The best I can work out the hated "Shuko" plugs have no provision for polarity. I have a set of wire cutters I use to install "Shuko" plugs.

You'd think the Dutch Germans & French would have more sense.

Actually the Schuko is polarized if it's used with the correct socket designed for the plug. It appears to me to be safer than the US style. Also if a earth/ground adapter is used with the Schuko plug it again becomes polarized for use on a 3 prong earthed socket. I have a small supply of the adapters that I bought in HomePro Pattaya for about 75 baht each.

[dotcom]

Longball. There is nothing to stop that plug being inserted the other way around. Thus polarity is not guaranteed. Thank you for the pictures.

[Crossy]

Longball. There is nothing to stop that plug being inserted the other way around. Thus polarity is not guaranteed. Thank you for the pictures.

The French and Belgian versions have a polarising pin as part of the outlet which also provides the ground (instead of having the side contacts).

The plugs we know as Schuko are actually a universal type that fits both the German http://www.kropla.com/!f.htm and French http://www.kropla.com/!e.htm versions

And you are correct, the German version fits either way round.

[longball53098]

Using the adapter in a standard 3 prong socket how can you reverse the plug?

Using the normal design plug and socket I can see reversal.

After making a closer examination of the adapter I can see it's design will also allow reversal

So I am bad and just assumed something here

[Crossy]

Using the adapter in a standard 3 prong socket how can you reverse the plug?

Using the normal design plug and socket I can see reversal.

After making a closer examination of the adapter I can see it's design will also allow reversal

So I am bad and just assumed something here

It's never wise to assume anything, particularly in Thailand

In this case appliances with Schuko plugs should be polarity insensitive, indeed all modern appliances really shouldn't care which way round they are connected. Gone are the days of 'live-chassis' TV sets with no transformers (the metalwork was connected to the neutral) and all the valve (tube) heaters connected in series with a dropper resistor straight across the mains.

Things like lamps are actually polarity sensitive, the switch should break the live (they almost never have a double-pole switch) and the live should go to the centre contact of the holder, then they get fitted with a non-polarised 2 pin plug

[dotcom]

Yep. I had a lamp in my living room like tha- reached in there to turn it on & I got a big shock off the brass socket.

[david96]

Thailand. Earthing point(s) on the MEA/PEA distribution network.

Where is the LV 220/380 Volt distribution system earthed? I have found no evidence of a visual connection to earth at the transformer neutral terminal or at any points on the distribution neutral. This should not be confused with earthing conductors used for the HV

system equipment or earthing of catenary wires for telephone systems or earthing of the transformer tank.

There is no main earth used in Thailand within the customers electrical instalation and all earthing where applied is direct to earth to an electrode or equivalent from the exposed metal work of equipment.

Customers 220 volt single phase supply is connected to an HRC fuse and 2 pole switch or directly connected to a 2 pole circuit breaker at the main switchboard. Metering is on the line

side of the main switch.

Two pin socket outlets are the normally installed, 3 pin are available but may not be earthed.

Every telephone line is earthed at the centre tap of the surge devices at the consumers premises, this earth is separate from any other earthing conductor.

[Crossy]

My comments in red. What you say was most definately true in the past but things are improving, slowly

Thailand. Earthing point(s) on the MEA/PEA distribution network.

Where is the LV 220/380 Volt distribution system earthed? I have found no evidence of a visual connection to earth at the transformer neutral terminal or at any points on the distribution neutral. This should not be confused with earthing conductors used for the HV

system equipment or earthing of catenary wires for telephone systems or earthing of the transformer tank. It depends where you are and where you look. Thailand theoretically implements the MEN or PME system for grounding the neutral, I have seen numerous examples of LV neutrals grounded at intervals (ours is every 3rd pole or so) and the local ground and neutral should be linked in the CU. That said I've also seen the same as you, no visible neutral grounding at the Tx (or anywhere else for that matter) which really is a requirement for system safety. There are also reports of some villages being wired delta with both poles of the outlets being hot to 150V or so above ground (220V phase-phase, same system as the Philippines). All adds to the fun

There is no main earth used in Thailand within the customers electrical instalation and all earthing where applied is direct to earth to an electrode or equivalent from the exposed metal work of equipment. Again, new installations have a main grounding spike with (sometimes) a PME / MEN link to the neutral in the CU. Local grounds tend to be used where there is no main grounding provided in an older installation.

Two pin socket outlets are the normally installed, 3 pin are available but may not be earthed. True, but all new installations are required to have 3 pin grounded outlets.

There really does not seem to be a national standard implemented, I've seen TT, TNS and TNCS wired installations with and without RCDs (again a non-negotiable as far as I'm concerned) along with several reports of L - N swaps at the meter

Care is required to ensure that what you think you've got is really what you've got.

[david96]

Yes, the LV distribution network neutral conductor is earthed at one or more points.

The transformer is the first place to check. As an electrician one has an interest in

the distribution system.

My observations in a previous post was to existing Thai electrical installations eg, the shophouse, townhouse and stand-alone houses wired since eg,1945.

Here are some further observations.

1. New Installations.

The MEA/PEA to determine if one can use the MEN (TN-C-S) or the TT system.

The MEN bond will be at the Main Switchboard if the TN-C-S system is used.

A main earth will be installed to an electrode. Example as in AS3000/2007.

Install 10ma or 30ma RCDs or RCBOs on all final subcircuits.

Obtain the connection requirements from the MEA/PEA in writing and their formal permission.

Obtain a test certificate when initial supply is connected to the installation.

2. Existing installations.

The earthing system will probably be non existant or not effective in most cases.

Check to see if there is an earthing system.

Instal RCDs or RCBOs on all final subcircuits until the installation is upgraded in the future.

Never presume that a 3 pin socket outlet is earthed or has an effective earth.

Many items of electrical equipment have 2 pin plug tops and extension leads have a 2 pin plug top and 3 pin outlet. Converter plugs from 2 pin to 3 pin with an earthing lug are available. 2 pin extension leads are common. This is why one should install RCDs.

Thai Industrial Standards (TIS) covers electrical equipment and cables used in Thailand.

There is no distinct Thai national standard for electrical installations at present. Thailand does compromise, using the standards of other countries as a basis, eg JIS and IEC.

Plug tops and sockets are Euro and JIS in general.

3. (Yes the 220V 3 wire system is still used in some areas, 220V 2 wire supply is taken from the 3 wire system, 127 volts to earth. Earthing is direct or TT. Eventually it will be replaced

with the 220/380/3ph/4 wire system. Economic for small loads)

4. 1. My personal view is that the TT system (no MEN bond) should be used with RCDs/RCBOs. Especially in rural areas. This is the most widely used system in developing (non Western) countries. 2. Polarity of L and N may not be guaranteed in some areas.

.

[david96]

If one carries out a visual inspection of general electrical installations in Thailand one will

find some or all of the following, the list can be expanded.

1 Ineffective earthing requirements or no earthing.

2 Exposed live terminals of electrical equipment.

3 Poor mechanical protection of cables and conduits

4 No mandatory RCD protection of socket outlets

5 Disused cables not removed or terminated in an approved manner

6 Cables run across roadways and footpaths in public areas

7 Earthing electrodes buried in concrete (connection not accessable)

8 Lack of formal testing requirements and inspections for electrical installations

9 Lack of safety awareness programmes by the MEA/PEA for consumer safety.

But one must admit this is common in many developing countries.

In many countries risk is accepted and the risk of receiving an electrical shock that will cause death or serious injury in Thailand is minimal.

Electric shocks can not be prevented but their effects can be minimised.

[Hssl]

http://www.wago.com/cps/rde/xchg/SID-53EFF...sl/gle-2631.htm

seen these in Pornchai next to the bus station Pattaya nua

My staff looked at me like i'd just invented the wheel!

[dotcom]

Thailand. Earthing point(s) on the MEA/PEA distribution network.

Where is the LV 220/380 Volt distribution system earthed? I have found no evidence of a visual connection to earth at the transformer neutral terminal or at any points on the distribution neutral. This should not be confused with earthing conductors used for the HV

system equipment or earthing of catenary wires for telephone systems or earthing of the transformer tank.

There is no main earth used in Thailand within the customers electrical instalation and all earthing where applied is direct to earth to an electrode or equivalent from the exposed metal work of equipment.

Customers 220 volt single phase supply is connected to an HRC fuse and 2 pole switch or directly connected to a 2 pole circuit breaker at the main switchboard. Metering is on the line

side of the main switch.

Two pin socket outlets are the normally installed, 3 pin are available but may not be earthed.

Every telephone line is earthed at the centre tap of the surge devices at the consumers premises, this earth is separate from any other earthing conductor.

Whether or not the LV system out in the street is grounded or not has little real effect on your residential situation.

That's because the supply to & from the meter is merely Live & Neutral. Those wires run to your load center (breaker box) at which point it is up to you to supply your own ground.

Just MHO.

[david96]

Here are some extracts from the Malaysian "Guidelines for Electrical

Wiring in Residential Buildings" 2008 edition. www.st.gov.my

INTRODUCTION

These Guidelines are based on the Electricity Supply Act 1990, The

Electricity Regulations 1994, MS IEC 60364:2003 Standard: Electrical

Installations of Buildings, MS 1936:2006 Standard: Electrical Installations

of Buildings – Guide To MS IEC 60364, MS 1979:2007 Standard:

Electrical Installation of Buildings – Code of Practice.

The Guidelines were formulated through discussions with representatives

from accredited institutions, technical officers (Safety and Supply) of the

Energy Commission headquarters and comments from the industry.

PURPOSE

The Guidelines For Electrical Wiring In Residential Buildings has been

prepared as a wiring guide for all Wiremen and Electrical Contractors for

undertaking electrical wiring in residential buildings to conform to the

Electricity Regulations 1994.

The Guidelines are prepared in a concise and compact manner to

facilitate the electrical wiring of residential buildings to be done adequately

and to ensure its safety of use while meeting basic wiring requirements.

The Guidelines will also be useful for owners of residential buildings or

wiring installations to recognise the requirements of safe and adequate

electrical wiring.

It is hoped that the Guidelines will ensure that electrical wiring will be

based on correct safety procedures and regulations and to avoid possible

electrical accidents. Safety requirements in electrical wiring works have to

be met to eliminate accidents causing physical injuries and loss of life or

property.

REFERENCES

Electricity Supply Act 1990;

Electricity Regulations 1994;

MS IEC 60364:2003 Standard: Electrical Installations of Buildings;

MS 1936:2006 Standard: Electrical Installations of Buildings – Guide To

MS IEC 60364; and

MS 1979:2007 Standard: Electrical Installation of Buildings – Code of

Practice

Electricity Supply Specifications

Electricity supply for domestic consumers, according to MS IEC 60038

standards, meets the following specifications: -

i. Single phase supply with nominal voltage of 230V, range +10%, -6%;

ii. Three phase supply with nominal voltage of 400V, range +10%, -6%;

iii. Permitted frequency is 50Hz + 1%;

iv. Earthing system type (TT System) as in Figure 2.1 and Figure 2.2.

All electrical equipment used must be suitable for operation with the stated

electricity supply specifications.

EARTHING OF ELECTRICAL INSTALLATIONS

7.1 Earthing

Earthing is a connection system between the metallic parts of an electrical

wiring system and the general mass of the earth. This will provide an

easy path with a low impedence or resistance to earth to enable the

protection system to operate effectively. It will thus ensure safety to

human beings/consumers from the dangers of electric shocks if earth

leakage currents are present. In general, an electrical installation is

earthed because of: -

i. Safety reasons.

ii. Protection system requirements.

iii. Need to limit over voltages.

iv. Need to provide a path for electrical discharge.

v. Legal requirements.

7.2 Classification of Earthing

Generally, earthing can be divided into 2 parts, namely: -

i. System Earthing

a. To isolate the system under fault conditions;

b. To limit the potential difference between conductors which are

not insulated in an area;

c. To limit the occurrence of over voltages under various

conditions.

ii. Equipment Earthing

Equipment earthing is undertaken to protect human

beings/consumers. If a live source comes into contact with the

equipment body, electrical energy will flow to the earth, without

flowing through the human being/ consumer’s body. This is because

of the fact that the human body has a greater resistance compared

with the resistance to earth.

7.3 Types and Functions of Earthing Accessories

Earthing accessories are as follows: -

i. Earthing Electrode

Copper jacketed steel core rods are used as electrodes for domestic

wiring.

ii. Equipotential Bonding

This is the conductor which is connected between the consumer

earthing point and the exposed metallic part. The minimum cable

size for this purpose is 10 mm2.

iii. Protection Conductor

This is the conductor which connects the consumer earthing point

with other parts of the installation which needs earthing. Its size is as

follows:-

a) Same size as the phase cable up to a size of 16mm2,

16 mm2, if the phase cable size is between 16 mm2, and 35

mm2,

c) Half the size of the phase cable if the size of the phase cable

exceeds 35 mm2.

7.4 Earthing Arrangements Using a TT System

i. The first alphabet indicates the earthing arrangements from the

supply side.

ii. The second alphabet indicates the earthing arrangement in the

consumer’s installation.

T – first: Indicates that the supply system has its own earthing

arrangements

T – second: Indicates that all metallic frames of the electrical appliances,

etc. are connected directly to earth.

RCDs are mandatory, 100ma for permanently connected equipment,

30ma for socket outlets and 10ma for socket outlets in wet areas and

water heaters.

[dotcom]

Shall we remind ourselves that Malaysia was once a colony of England?

Nothing wrong with that mind you. England has a fantastic set of paradigms for elec wiring.

However you are not in Malaysia - no more than you are in England.

[david96]

Shall we remind ourselves that Malaysia was once a colony of England?

Nothing wrong with that mind you. England has a fantastic set of paradigms for elec wiring.

However you are not in Malaysia - no more than you are in England.

It was supplied on an informative basis only for the technically minded reader.

[loong]

Well, I've been planning on making the wiring in this house safer and I'm starting today.

The house was finished 18 months ago and typical Thai electrical installation, only safety feature is one fuse on the incoming supply.

Yesterday switched on the bathroom light and BAAAAM!!!! The whole village's power supply went out. I guess a mouse had chewed through the wiring and caused a short. Certainly blew the cable to pieces.

So what does this mean?

That the fuse is on the F***ing neutral, so not even the very limited protection that this offers!

Now I don't know whose fault this is, the house was wired before the meter was installed, so it may be the power company that didn't check.

Very scary

[Artisi]

Well, I've been planning on making the wiring in this house safer and I'm starting today.

The house was finished 18 months ago and typical Thai electrical installation, only safety feature is one fuse on the incoming supply.

Yesterday switched on the bathroom light and BAAAAM!!!! The whole village's power supply went out. I guess a mouse had chewed through the wiring and caused a short. Certainly blew the cable to pieces.

So what does this mean?

That the fuse is on the F***ing neutral, so not even the very limited protection that this offers!

Now I don't know whose fault this is, the house was wired before the meter was installed, so it may be the power company that didn't check.

Very scary

What has taken you so long to think about your safety - or are you into extreme (electrical) sports, like zap me if you can, or do you have a death wish.

One other point - fuses are there to protect wiring not for personal safety.

[t.s]

I am like Tywais and hold a EE degree and by no means have a journeyman's license when it comes to either domestic or commercial electrical wiring. But I have remodeled a few of my previous homes in the USA and performed all the electrical work (was inspected by a journeyman and state inspector) so I have no problems with dealing with most electrical wiring.

However since coming to LOS and now living here to see how they wire their infrastructure for electrical distribution I have have no faith in Somchai whether it be domestic or industrial wiring....

thing is the mess you usually see is telephone wires, not electrical.

[Crossy]

thing is the mess you usually see is telephone wires, not electrical.

With a handful of cable-TV thrown in for good measure

[dotcom]

So what does this mean?

That the fuse is on the F***ing neutral, so not even the very limited protection that this offers!

Now I don't know whose fault this is, the house was wired before the meter was installed, so it may be the power company that didn't check.

I believe the answer lies in your above statement. In my case when MEA came out to install my new 30/100 meter they reversed the polarity. 99% that's what happened to you.

You can buy a tester screwdriver at any hardware store. You can check your own live & neutral.

Buy a safety-cut too. Have it installed.

Ditch the "fuse" & get "breakers" (one per circuit). That will go a long way toward upgrading your wiring

[loong]

So what does this mean?

That the fuse is on the F***ing neutral, so not even the very limited protection that this offers!

Now I don't know whose fault this is, the house was wired before the meter was installed, so it may be the power company that didn't check.

I believe the answer lies in your above statement. In my case when MEA came out to install my new 30/100 meter they reversed the polarity. 99% that's what happened to you.

You can buy a tester screwdriver at any hardware store. You can check your own live & neutral.

Buy a safety-cut too. Have it installed.

Ditch the "fuse" & get "breakers" (one per circuit). That will go a long way toward upgrading your wiring

Actually, I was mistaken. That white round ceramic thing that I assume is a fuse (not so sure now) was connected in the live side, just had a grey wire which should indicate neutral (but this is Thailand). It also had exposed metal connections that you could touch.So if the "fuse" was on the live side, I have to wonder why when the damaged cable earthed via the metal roof struts it blew the village's transformer fuse.

Anyway, I have bought and fitted a consumer unit with RCD, so am a bit happier now. We have no earth, but at least the RCD will give some protection? So next on the list is putting in an earth rod and changing all the sockets to decent 3 pins.

Question for the experts here. The earth rod should go into the ground about 1.5 Metres. Is it okay on land that has been built up by more than 1 metre and concreted over? Ie make a hole in the concrete and drive the rod into the built up soil below.

Thanks

[dotcom]

Try & find a rod about 2 meters long & yes that should be fine.

Crossy will tell you to make sure the connection (clamp) is accessible always.

That white ceramic thing is a fuse holder. A breaker you only buy once.

[Crossy]

Crossy will tell you to make sure the connection (clamp) is accessible always.

So will the UK and Aussie regs

No problem cutting a hole in your slab for the rod.

I would get one of those floor drains with a cover to put over the rod/hole so you can bash the rod below floor level but still be able to get at it to check the connection and maybe bung some water down occasionally if it's really dry. Failing that a short bit of PVC with an end cap (not glued) would do the trick.

[loong]

Thanks for the advice

[Artisi]

I would put the earth rod right next to an outside tap that might get some regular use, this way you can ensure the ground in this area doesn't completely dry out.

[Freddie_fly]

yes , it was a bit of a shock when i started to look closely at the work being done , but their attitude when i complained was that it wasnt really their fault because they were very busy and had to sub contract !!

they were silent and red faced when i showed them the sanitary towel though !

I assume they sub-contracted to Somchai and his cousin then???, So you are slanging a European company because of work done by a sub-contractor. Fair enough the main contractor has responsibility but maybe you nedd to identify the shoddy work culprit first rather than just say a "european company" did this.

regards

Freddie

[loong]

yes , it was a bit of a shock when i started to look closely at the work being done , but their attitude when i complained was that it wasnt really their fault because they were very busy and had to sub contract !!

they were silent and red faced when i showed them the sanitary towel though !

I assume they sub-contracted to Somchai and his cousin then???, So you are slanging a European company because of work done by a sub-contractor. Fair enough the main contractor has responsibility but maybe you nedd to identify the shoddy work culprit first rather than just say a "european company" did this.

regards

Freddie

Taxexile is absolutely right. If a company uses a subcontractor, they should make sure that the sub is up to the task. If they are so busy that they have to use "Cowboys", they should not take on the work. The main contractor is totally to blame for shoddy and dangerous work.

[Freddie_fly]

yes , it was a bit of a shock when i started to look closely at the work being done , but their attitude when i complained was that it wasnt really their fault because they were very busy and had to sub contract !!

they were silent and red faced when i showed them the sanitary towel though !

I assume they sub-contracted to Somchai and his cousin then???, So you are slanging a European company because of work done by a sub-contractor. Fair enough the main contractor has responsibility but maybe you nedd to identify the shoddy work culprit first rather than just say a "european company" did this.

regards

Freddie

Taxexile is absolutely right. If a company uses a subcontractor, they should make sure that the sub is up to the task. If they are so busy that they have to use "Cowboys", they should not take on the work. The main contractor is totally to blame for shoddy and dangerous work.

Read my post again,

I agreed that the main contractor had responsibility for the work, My point is that it would be nice to know the sub-contractor used so that anyone else can make sure they dont use the same.

regards

Freddie

[loong]

Read my post again,

I agreed that the main contractor had responsibility for the work, My point is that it would be nice to know the sub-contractor used so that anyone else can make sure they dont use the same.

I read your post again.......

I assume they sub-contracted to Somchai and his cousin then???, So you are slanging a European company because of work done by a sub-contractor. Fair enough the main contractor has responsibility but maybe you nedd to identify the shoddy work culprit first rather than just say a "european company" did this.

...and you seem to be saying that the blame lies more on the shoulders of the subcontractor than the Main contractor. The contractor should oversee all work carried out by employees and subcontractors and make sure it is up to standard.

"I'm sorry that we put your family's life in danger, but we were busy and had to send incompetents to do the work and couldn't be bothered to check the standard of their work" is really not good enough.