Electricty Supply 220 Volt In Thailand

[Negita43]

Hi Crossy sorry to be a bore but I have some more questions

1. I went with electrician to get the cable - I wanted to buy 2 core + earth (a la Europe) he insists on separate cables.

Do you think that makes it easier for him to cheat? (stealing neutrals etc)

2. He wanted white black and green I insisted on red (live) black (neutral) green earth a la your web site

What worries me is that he will use red for neutral and black for live! or worse not be consistent!

In the UK I had a small plug I used on my camper van in Europe which could tell me if the polarity was reversed (live and neutral) can you get them over here? Otherwise am I correct in thinking that if I put my digital multimeter in the plug red to live terminal and black to neutral if it has been wired the wrong way the meter will show a minus 220( ha ha I know I'll be lucky to get 220V) reading

3. I lived in Spain for 10 years and there I could have a 3.5 kva , 5 kva or 7 kva supply. Most houses had 3.5 KVA BUT it wasn't enough to run everything - if you had the dishwasher on you had to off the aircon !

At the moment my supply is 'a Builders' supply. When I actually have the house supply installed can you choose your KVA or is it take what we give you?

4. Where is a good place to instal the earth rod (don't say in the earth!) I mean are there locations to avoid

for example next to the supply pole?) My soil is clay once you are 1 meter down it holds the water (and I know this may give problems with my septic tanks run offs) but as water is a good conductor I'm not sure what the implications are for the earth rod

5. Finally, the CU box I have at the moment has mcb's etc marked 63 sure (-L -I think). What the max KVA that this could cope with I've also checked the rcd which is an IEC61008 -1 which makes it a RCCD type A I think.

Thanks again

[Crossy]

1. Twin + earth is difficult to find here, singles are easy and common but MUST be in conduit. He WILL borrow neutrals, Thai sparks have no knowledge of how RCDs / RCBOs work (or don't work) so if you're planning a split service board, good luck.

2. Black-live, White-neutral, Green-earth is standard in Thailand, and it is detailed on the website here http://www.crossy.co.uk/wiring/colour%20codes.html but nothing to stop you using the old Euro standard Red-live, Black-neutral, Green-earth.

Not seen the plug-in testers here, import one from a 220V country and make an adaptor.

3. You will likely be offered a 15/45 meter, which should be adequate unless you have a lot of aircons, do a maximum demand calculation you could possibly get a 30/100 supply but if not and 15/45 isn't enough then time to consider 3-phase.

4. Install your rod as close as possible to the distribution board.

5. If your incomer is 63A (normal for a 15/45 supply) expect to keep your maximum demand below about 50A (11kW) peaks to 75A (16.5kW) for short periods (<10 minutes) should also be OK.

[TS79]

1. Twin + earth is difficult to find here

Not so difficult anymore, just pretty expensive. Homepro stocks it. Its actually triple rather than an uninsulated earth core.

HomePro prices are (approx):

3400 baht for 100m of 2 x 2.5mm2 conductors and 1 x 1.5mm2 conductor

2700 baht for 100m of 2 x 1.5mm2 conductors and 1 x 1.0mm2 conductor

If sourced from a trade electrical shop will probably be cheaper.

[Negita43]

Thanks TS79

Yes I know I had already purchased some from Do Home and returned it and replaced it with individual cables and trunking but I didn’t want to be ‘picky’ with Crossy who is a mine of useful and more important information (and very prompt in replying).

The sparks is due to start very soon and I am very concerned about this thing about stealing neutrals (HOW CAN I TELL?) because I am determined to have a safe system with an RCD

I can’t find a ABB CU anywhere here in Korat and I have now located a 10 way Unit with DIN bus and a RCBO. I am pretty sure it can be configured to be split by moving the RCBO along the board. This will require the purchase of some 10mm? cable so that the connection can be made between the main switch and the RCBO. (I have found that home pro sells 10mm black by the meter (and a reel of red insulating tape will give me red and black as per the CU unit.

The Unit is made by a company called CEO (Criter electrical) anyone have knowledge of this unit?

Also I am wondering if maybe I should firstly install the RCBO where it is (protecting all the MCB’s) and only and split the system if I have problems (I am perfectly capable of doing that myself) In fact I could wire the whole thing myself. BUT I work and the builder wants to move forward towards plastering and I just don’t have time.

And if you are reading this Crossy I would get you to come and do it BUT I suspect you don’t live anywhere near Korat!

[Negita43]

TS79

In my previous post when I said more 'important information' I didn't mean that as an insult to you

Poor phrasing on my part.

Apologies

Mike

[Crossy]

I'd be more than happy, but you're right, nowhere near Korat and I too have a day job.

Up to you, but I would install as split first, then go to whole house RCD when you have problems. You will need to split the neutral bar so that the 'protected' neutral is fed via the RCD as shown in the picture on the website. All the neutrals associated with protected MCBs need to got to this bar and all the others to the un-protected bar.

Any borrowed or crossed neutrals will result in your RCD tripping constantly.

Fun is about to be had by you

[TS79]

TS79

In my previous post when I said more 'important information' I didn't mean that as an insult to you

Poor phrasing on my part.

Apologies

Mike

No worries. Crossy is indeed a gem and always enjoy reading his practical replies. I just thought it worthwhile letting people know 3 core is becoming more available in the market.

[Crossy]

Indeed TS, I should have said "twin and earth can be difficult to find"

[Negita43]

Thanks again

I like your choice of the word 'when' rather than the word 'if' when talking about my problems!!

But what exactly is a borrowed or crossed neutral and can I : A) test for it visually see it from the cabling.

If I was doing it myself it would be easy because I would use twin and earth and take everything back to the

back to the CU. Maybe more cable than I need to use but sure.

By the way do they use a ring main system here or is it like 1 big spur

Mike

[electau]

To check for crossed neutrals you will have to test each circuit individually, and that means disconnecting each circuit. there should be no connection of neutrals between circuits. If you have this problem you will have to check at each light switch where the neutrals are terminated. This applies to all circuits including socket outlets. Use the ohms scale of a multimeter to test.

Colour codes (TIS) L black, N white or grey, E green or green/yellow trace.

The ring type circuit must never be used within an electrical installation, it is used only in the UK. All circuits must have a protective device ie MCB or RCBO at the point of origin of the circuit. All circuits are wired in a star configuration from the switchboard.

Ring main is sometimes referred to as the grid connection of a LV distribution system. This is not part of the electrical installation.

[Negita43]

Thanks electau

Please can you explain 'Use the ohms scale of a multimeter to test'. What reading or lack of reading am I looking for and between what terminals L/N, L/E, N/E,?

Some time ago Crossy gave me some voltages to test at the meter:

'Clearly identify the neutral conductor at the meter and at the switchboard, the neutral terminals of the meter are the two centre ones. Correct polarity is L to N 220V, L to E 220V and N to E 0 volts'.

Can I use this to test the plugs?

Electrician was supposed to start saturday when I would be there BUT he has turned up today when I'm at work!

Thanks

[Negita43]

Hi Crossy/Electau

I am sorry to keep bothering you about electrical things but I am just trying to get things straight in my head before I (or more correctly let the Thai Sparks) start.

Firstly, I have been looking at your ‘more elegant solution’ on your website. Am I right in thinking that this could be achieved by buying two boxes - one for unprotected with just the main switch/MCB’s and one with RCBO/ELCB and MCB’s and linking them via some round conduit and cable? (Of all the CU units I’ve looked at I haven’t seen one that has a neutral bar that can be split). If so would 10mm cable be ok or bigger?

Secondly, Am I right in thinking that the lighting circuits are the most likely source of borrowed neutrals and if so why not put the lighting circuits on the unprotected side.

Thirdly, as this is a completely new build most of the appliances will be new do I still need to worry about ‘leaky’ appliances? OR is 'leaky a function of appliance type not age

If so what appliances would you put on the unprotected side – Dishwasher?, washing machine?, aircon? Shower, water pump? (I assume it’s anything that is likely to draw a lot of power on start up is that correct??)

Finally, I have a 90 cm high by 126meter area under the house for storage which I want to put some plugs and lighting into, this will be walled and doored (yes I know no such word) I was thinking of surface mounted IP 45 for this – can you get them out here??

Mike

[electau]

All circuits must be protected by an MCB or an RCBO.

If you use the TT earthing system RCD protection must be on all circuits.

If you use the TN-C-S (MEN) system only socket outlets require RCD protection, although in Thailand it would be advisable to use RCDs on all circuits.

Earthing by means of PE conductor(s) at all points of utilisation, eg socket outlets, and permanently conected equipment.

The current rating of the protective device will depend on the current rating of the conductor to be protected. eg. 20A MCB or 20A/30mA RCBO. Socket outlets 2.5sqmm 20A.

Crossed neutrals can occur across lighting and power circuits.

You will not have any problems if your installation is tested before connection to supply and if defects are found they must be rectified immediately and then retested. Polarity tests must also be carried out L to N, L to E and N to E.

If an electrician can not carry out the tests required he is not competent to carry out installation work.

When an electrical installation is connected to supply it must be free as far as practicable from electrical risk, ie, electric shock and fire.

If power and light switches are not exposed to the weather they need only be IP54 or the standard switch and socket outlet to TIS ( Thai Industrial Standards).

The insulation resistance of all new equipment must be at least 1.0Megohm or higher (in practice 20 to 50M ohms +).

(You should not be concerned to much re " leaky equipment" all equipment exibit some leakage current, eg, surge protectors and some electronic equipment such as split mode power supplies).

10sqmm copper ( L and N) is suitable to link the two distribution boards.

Edited November 8, 2012 by electau

[Crossy]

What he said ^^^ although finding a sparks who has (and knows how to use) any test gear more advanced than a neon screwdriver may be a challenge.

Whether your installation is TT or MEN I would ensure my water heater is on an RCD protected circuit.

[electau]

Thanks electau

Please can you explain 'Use the ohms scale of a multimeter to test'. What reading or lack of reading am I looking for and between what terminals L/N, L/E, N/E,?

Some time ago Crossy gave me some voltages to test at the meter:

'Clearly identify the neutral conductor at the meter and at the switchboard, the neutral terminals of the meter are the two centre ones. Correct polarity is L to N 220V, L to E 220V and N to E 0 volts'.

Can I use this to test the plugs?

Electrician was supposed to start saturday when I would be there BUT he has turned up today when I'm at work!

Thanks

Use the lowest range x1 in the ohms range for earthing continuity in practice it will be less than 2 ohms.

Use the highest AC voltage range to measure voltage between L and N 220, L and E 220, and N and E ) 0 volts .There may be a very small rise on the N to E reading, you can disregard that in practice.

NEVER use the ohms range or any current range to measure voltage. Check you instrument on a known source of voltage before using. Zero the leads together before taking any continuity tests.

[Negita43]

Thank you again

But to test the earth continuity where do I put the two probes on the multi meter?

If I have to put one end in the CU earth and the other on the earth connection in the plug/switch I will need a lead of at least 20 meters to test the furthest plug! forgive my ignorance on this I have only ever used a multimeter to test voltage!

Mike

[electau]

Thank you again

But to test the earth continuity where do I put the two probes on the multi meter?

If I have to put one end in the CU earth and the other on the earth connection in the plug/switch I will need a lead of at least 20 meters to test the furthest plug! forgive my ignorance on this I have only ever used a multimeter to test voltage!

Mike

Yes. you will require a long trailing lead attach one end to the earth bar at the switchboard and the other to one probe. The other probe to all points where there is an earth. this will prove earth continuity. You should do the same with the main earth with the probe on the electrode.

[Negita43]

Hi Crossy and Electau

Remember my IP 45 Oil can

Here's a picture of it now and a picture of how the bulder is now taking his power - the blade fuse is no more

As soon as I discovered it I insisted he puts a blade fuse in the line

We will see but if he blows up the meter he will have to pay me the 8000 baht deposiit we made on the builders supply meter

I don't suppose I should be surprised that it expired as they have been using 2 ancient welders and 2 cutters simultaneously !!!!!!

hey ho

[electau]

Welding can be done off site at a workshop and the steel framework and roof trusses transported to site and then erected and bolted together. Your concrete slab is poured first with the footings. There is real reason to use a welder on-site with a residential type structure.

As the photo shows, the welder circuit has no protective device or earthing.

[Negita43]

Hi all

Another electrical question

My hose should have two or three 3 way switches (ie you can switch on/off from 3 different locations. My electrician is honest enough to say he has never installed one before. Can anyone supply me with a diagram of the wiring for such a switch?

[Khonwan]

Google "3 way 4 way switch diagram" for loads of good info and pictures.

[Crossy]

Two-way switches (top and bottom of stairs) are readily available and easy to wire. As above plenty of results on Google, there are several ways of wiring two-way switches but all work equally well.

This page has good clear diagrams. http://cubus-adsl.dk...y_switching.php

Your big issue will be finding intermediate switches (to add extra switching locations) as few locally available manufacturers make them and fewer electrical outlets carry them (or know what they are).

[electau]

Two way switches are often used as the standard switch. they have three terminals 1- C- 2.

C, the common terminal switches between 1 or 2.

To wire a 2 way switched fitting the usual method is to run a twin between the 2 switches on terminals 1 and 2. the common C connects to the L for one switch and the other C terminal on the second switch is run to the SL terminal of the fitting. SL switched line or active.

The switching must NEVER be on the neutral conductor.

For a third or further switch in the circuit an intermediate switch is used it has 4 terminals and is connected in the twin pair between the other 2 switches. Intermediate 1-2 and 3-4. switches to 1-3 and 2-4.

Source. HPM, Clipsal. Clipsal fittings are available in Thailand.

[Negita43]

Hello everybody – the electrical saga continues – After much to-ing and fro-ing worrying and sleepless nights I have decided on the following configuration.

1. Box (CEO) with only a main switch and MCBs for the Aircon (4 units +etc and future expansion??)

2. A bigger Box with RCBO and a surge protector for the rest of the house. BOTH DIN rail type. Rated C63 I bought the units complete with MCB’s etc. see fotos

On studying them I see some things that concern my novice eye – maybe someone can soothe or confirm my worries –

All the MCB’s appear to marked at 6000 - amps, milliamps???

BUT the main switch and the RCBO on the bigger (CYK) unit are marked 4500. AND the main switch on the CEO box is marked 100000.

My tidy mind worries about these different values on things within the same system

Any thoughts suggestions?

Next Can anyone one suggest how I can link the two boxes together or do I need two separate feeds.

Looking in the two units I see one is a top feed(CEO) and the other (CYK) a bottom feed.

Finally, my electrician says he wants 25mm copper from the meter to the CU unit. I thought that 16mm would have been enough and if he uses 25mm that will probably make any connections between the units very difficult.

Finally, finally, I told the electrician I wanted red live, black neutral, green earth. Today he has pulled some cable through the conduit - I notice every one as a black, green AND BLUE cable – hey ho – I suppose that it doesn’t matter as long as he is consistent with his connections BUT why can’t they ever remember anything for more than a few hours – unless of course you owe them money and that they never forget!!!

PS After I had bought the two boxes above ABB sent me these two attachments don’t know if they are of any use to anybody.

OVR T2.pdf

Catalogue SPD 2011-72dpi.pdf

[electau]

The load centre should be 1 x 2 pole MCB 63A C frame 10kA @ 220V

Each final circuit connected to its own MCB one module 18mm wide.

Min. number of circuits.

2 lighting and fans, 2 socket outlets, one circuit for each permanently connected item of equipment over 10A, eg aircons, hws, etc. Final circuit protection devices rated to the current carrying capacity of the cable to be protected. (3kA minimum)

The existing MCBs may be replaced with RCBOs, 10mA or 30mA. or an RCBO/RCD unit may be installed between the main switch and the line side of the final circuit protective devices. the RCBO can be installed above the load centre.

Cable colours for to Thai Industrial standards are black/line, white/neutral, and green or green/yellow for earth. You should not change these.

There is no problem with installing 25sqmm cable it is easier to work with as it has 19 strands instead of 7. Make sure it is PVC insulated and PVC sheathed.

Current ratings for circuits.

Lighting and fans, 10 A or 16A. Socket outlets 20A. Cable sizes, 1.0sqmm 10A, 1.5sqmm 16A, 2.5sqmm socket outlets. Aircons HWS etc as per full load current.

Max number of points per circuit lighting 0.25A each unlimited number not to exceed current rating of cable. Socket outlets 10A, max 20 per circuit, 1 amp per outlet. A twin outlet is 2 sockets.

Edited November 29, 2012 by electau

[electau]

The main neutral should be clearly identified by white sleeving ( eg heat shrink) or othe approved means if the cable is of another colour. Green or green /yellow must NEVER be used as a current carrying conductor under normal operating conditions. An earth conductor only carries current under fault conditions.

[electau]

The figures 4500, 6000, 10000 refer to prospective short circuit current. You do not have to be concerned with this as the actual short circuit current at your switch board will depend on the size of transformer and the impedance of your consumers mains and that of the distribution cables. The firures mean that an MCB has been type tested to a particular value and time anywhere between 0.1 and 1 sec depending on the standard and testing authority.

Your prospective short circuit current will be far below these figures.

Edited November 30, 2012 by electau

[Negita43]

A million thanks electau

Mike

[Negita43]

Hi again,

This time a question about the supply cable:

My supply cable will be underground from the meter

I have beed told this must be 25mm (copper) - It's very expensive!

The cheapest I can find is in Global at around 8,200 for 100 meters I reckon I need about 30 meters to reach the CU so X 2 (live + neutral) that's 60 meters . Two questions:

1. The cable label says code 4? what does this mean?

2. What size should the earth cable from the CU to the earth rod be and should it be insulated or bare copper

If insulated coiuld I use the black 25mm (I would have 40 meter spare) suitably marked (green electrical tape).

Thanks again

[electau]

Hi again,

This time a question about the supply cable:

My supply cable will be underground from the meter

I have beed told this must be 25mm (copper) - It's very expensive!

The cheapest I can find is in Global at around 8,200 for 100 meters I reckon I need about 30 meters to reach the CU so X 2 (live + neutral) that's 60 meters . Two questions:

1. The cable label says code 4? what does this mean?

2. What size should the earth cable from the CU to the earth rod be and should it be insulated or bare copper

If insulated coiuld I use the black 25mm (I would have 40 meter spare) suitably marked (green electrical tape).

Thanks again

If permitted by the PEA you could use 35sqmm Aluminium. You will have to use the correct terminations Al/Cu links. Copper coductor would be better.

The main earth conductor should be 10sqmm copper insulatedand itentified in this case at each connection by green heatshrink sleeving or other approved means.

Cable should be PVC sheathed PVC insulated single, temp rating 70C.