Electrics for new house - can it be explained in layman's terms?

[Sophon]

Thanks to you both, so it seems I can go either way. I will see what my electrician prefers before deciding.

And no Crossy, I'm not going to light up Wembley. The most that will be on any light circuit is one of the 32W circular fluorescent tubes, so since you say a 1.5 mm² can handle 15A, I guess the load will only be about 1% of maximum.

Sophon

[Sophon]

As mentioned the downstairs will be powered by a main circuit consisting of 2.5 mm² live/neutral wires. Downstairs consists of one big room, and the circuit wires will be brought down from the breaker box upstairs. Once downstairs the wires will run around the room and supply the different lights and outlets.

Since the wires more or less will have to do a complete loop of the room anyway, would you close the loop or keep it open? I don't know if there is any disadvantages of closing the loop, but I guess one advantage would be that should a connection come loose somewhere in the circuit the subsequent lights/outlets would be supplied with power "the other way around".

Sophon

[Crossy]

If you're going to 'close the loop' don't increase the breaker as you would with a UK style 'ring main'. Of course, you would then be masking any fault.

Personally I would not bother, it may will cause confusion to a sparks who come along later.

[bankruatsteve]

Do not make it a ring circuit. That concept, although still common in the UK (?) has more cons than pros and implementing in LOS is sure to get <deleted>.

[Sophon]

OK, I will leave the loop open.

Thanks for your replies.

Sophon

[Sophon]

New month, new questions.

Dimmer switch:

• I am thinking of installing a dimmer switch in the main bedroom, but from what I have read they don't work with standard energy saving bulbs (LED and CFL). There are special such bulbs available, but apparently the dimmer switches may not work properly with these either.
  Does anyone have experience with dimmer switches and energy saving light bulbs here in Thailand?
• I am assuming that dimmer switches are connected the same way as standard switches, so that I will easily be able to switch back to a standard switch later, if the dimmer switch turns out to be more trouble than it's worth.
  Is that a correct assumption?

Two-way switches:

• We will have two-way switches at opposite ends of the corridor leading to the bedroom section of the house. When reading up on dimmer switches I found websites mentioning that two-way switches might not work properly with energy saving light bulbs either. I can understand why they might not work with dimmer switches, but I can see no reason why they wouldn't work with two-way switches.
  Is it correct that energy saving light bulbs might have problems with circuits with two-way switches?
• I also read (on UK centric websites), that two-way switches might be bigger in size than standard switches. I need to have two-way switches and standard switches together in the same box, so it would cause me problems if they don't fit together.
  Are two-way switches (here in Thailand) the same size as standard switches so that they fit with the normal front plates for the electric boxes?
• As I understand it the two two-way switches will be connected together L1 to L1, L2 to L2 and Common to Common. Incoming live will go to L1 and the live wire to the lamps will come from L2. Other than that the lamp will, of course, also be connected to the circuits neutral wire. Any of the three wires connecting the two two-way switches may at any time be live (depending on the switch positions).
  Assuming that the live wire is black and the neutral is white, which colour(s) would you recommend for the three wires connecting the two switches?
  I am thinking I will just use black wire to make it clear, that they are all potentially live.

Outlets with on/off switches:

• For the kitchen counter we want to have electric outlets with on/off switches. This would allow us to keep frequently used appliances without their own on/off switches such as the water kettle and rice cookers connected, instead of having to plug/unplug them every time we use them. The only brand I can find locally here in Lamphun/Chiang Mai are Chang (I have looked at the usual places such as Global, Thai Watsadu and Home Pro).
  Does anyone have good/bad experiences with switched outlets generally, and with the Chang brand in particular? Is it something I should avoid?

Double switch boxes:

• In a number of places I will have two light circuits controlled from the same switch box. The circuits will be on the same main circuit, so can use the same live and neutral. Splitting the live wire at the connection box at the top of the conduit (in the attic) would mean two live wires going to and from the two switches (four total), while splitting behind the switches would mean only one incoming live wire (three total). My guess is that the split should be in the top connection box.
  Where should the the live wire be split, at the switch box or at the top connection box?

Internet/TV/power circuits:

• It is my understanding that electric wires and TV coaxial cables should never be in the same conduit (to avoid interference).
  How far away from each other should TV/electric wires be?
• Can electric wires and internet cable be closer together, or does the same apply as for TV cable?
• I am thinking that TV and internet cables should be able to co-exist in the same conduit (relevant if I want to run internet cable to the TV in case I buy a smart TV). Is that correct?

To bend or not:

• We have already had the discussion about whether to twist or not (with regards to cable nuts), now it's time for "to bend or not". When connecting a wire to a receptacle where the wire will be held in place by a screw pushing it against the casing such as the ground/neutral bar on the distribution board, do you bend the wire double before inserting it (assuming it will fit)?

Electric shop/outlet:

• We need some wires, that I haven't been able to find at the "usual suspects" (Global/Thai Watsadu/Home Pro)
  20 m. 16 mm² green THW for the main ground from the ground rod
  20-25 m. 6 mm² black (red would be OK too) THW live wire to the water heaters
  20-25 m. 6 mm² white THW neutral wire to the water heaters
  20-25 m. 2.5 mm² green THW ground wire to the water heaters
  Some I cannot find at all, others I can find in different colours but only if I buy them in 100 m. rolls. Most of these wires are not cheap at all, so I really don't want to end up with 75-80 m. left over after we are finished.
  Anyone who can recommend a shop in Lamphun/Lampang/Chiang Mai with a big selection of wires that are sold by the meter?
  An internet shop would be OK too.

As always, your help or input is much appreciated.

Sophon

[Forkinhades]

Wow a lot here

Dimmer switch:

• I am thinking of installing a dimmer switch in the main bedroom, but from what I have read they don't work with standard energy saving bulbs (LED and CFL). There are special such bulbs available, but apparently the dimmer switches may not work properly with these either.
  Does anyone have experience with dimmer switches and energy saving light bulbs here in Thailand?
• I am assuming that dimmer switches are connected the same way as standard switches, so that I will easily be able to switch back to a standard switch later, if the dimmer switch turns out to be more trouble than it's worth.
  Is that a correct assumption?

LED's can be dimmed, but you will need drivers, and 10V dc dimmers (IMO the way to go) not sure of availability inLOS

Two-way switches:

• We will have two-way switches at opposite ends of the corridor leading to the bedroom section of the house. When reading up on dimmer switches I found websites mentioning that two-way switches might not work properly with energy saving light bulbs either. I can understand why they might not work with dimmer switches, but I can see no reason why they wouldn't work with two-way switches.
  Is it correct that energy saving light bulbs might have problems with circuits with two-way switches?

BS

• I also read (on UK centric websites), that two-way switches might be bigger in size than standard switches. I need to have two-way switches and standard switches together in the same box, so it would cause me problems if they don't fit together.
  Are two-way switches (here in Thailand) the same size as standard switches so that they fit with the normal front plates for the electric boxes?

should be same size

• As I understand it the two two-way switches will be connected together L1 to L1, L2 to L2 and Common to Common. Incoming live will go to L1 and the live wire to the lamps will come from L2. Other than that the lamp will, of course, also be connected to the circuits neutral wire. Any of the three wires connecting the two two-way switches may at any time be live (depending on the switch positions).
  Assuming that the live wire is black and the neutral is white, which colour(s) would you recommend for the three wires connecting the two switches?
  I am thinking I will just use black wire to make it clear, that they are all potentially live.

Black. There are 2 ways methods to connect up 2 way switches, method 1 has live (feed) and switch line at one switch, method 2 has live at one switch and switch line at other), advise what you have

Outlets with on/off switches:

• For the kitchen counter we want to have electric outlets with on/off switches. This would allow us to keep frequently used appliances without their own on/off switches such as the water kettle and rice cookers connected, instead of having to plug/unplug them every time we use them. The only brand I can find locally here in Lamphun/Chiang Mai are Chang (I have looked at the usual places such as Global, Thai Watsadu and Home Pro).
  Does anyone have good/bad experiences with switched outlets generally, and with the Chang brand in particular? Is it something I should avoid?

scheinder do a very good range, and available

Double switch boxes:

• In a number of places I will have two light circuits controlled from the same switch box. The circuits will be on the same main circuit, so can use the same live and neutral. Splitting the live wire at the connection box at the top of the conduit (in the attic) would mean two live wires going to and from the two switches (four total), while splitting behind the switches would mean only one incoming live wire (three total). My guess is that the split should be in the top connection box.
  Where should the the live wire be split, at the switch box or at the top connection box?

try to avoid connection boxes.

Internet/TV/power circuits:

• It is my understanding that electric wires and TV coaxial cables should never be in the same conduit (to avoid interference).
  How far away from each other should TV/electric wires be?

With the screen of coaxial and protection of conduit, a minimum distance is not required.

• Can electric wires and internet cable be closer together, or does the same apply as for TV cable?
• I am thinking that TV and internet cables should be able to co-exist in the same conduit (relevant if I want to run internet cable to the TV in case I buy a smart TV). Is that correct?

try to keep separate with conduits. 1 for power 1 for tv, and 1 for internet

To bend or not:

• We have already had the discussion about whether to twist or not (with regards to cable nuts), now it's time for "to bend or not". When connecting a wire to a receptacle where the wire will be held in place by a screw pushing it against the casing such as the ground/neutral bar on the distribution board, do you bend the wire double before inserting it (assuming it will fit)?

cables above 2.5mm do not need to be doubled over bent

Electric shop/outlet:

• We need some wires, that I haven't been able to find at the "usual suspects" (Global/Thai Watsadu/Home Pro)
  20 m. 16 mm² green THW for the main ground from the ground rod
  20-25 m. 6 mm² black (red would be OK too) THW live wire to the water heaters
  20-25 m. 6 mm² white THW neutral wire to the water heaters
  20-25 m. 2.5 mm² green THW ground wire to the water heaters
  Some I cannot find at all, others I can find in different colours but only if I buy them in 100 m. rolls. Most of these wires are not cheap at all, so I really don't want to end up with 75-80 m. left over after we are finished.
  Anyone who can recommend a shop in Lamphun/Lampang/Chiang Mai with a big selection of wires that are sold by the meter?
  An internet shop would be OK too.

Cant help on that one

As always, your help or input is much appreciated.

Sophon

[thomasteve]

A standard 230V dimmer switch unit is not suitable for use with CFL or Fluorescent tubes - only for use with regular incandescent and possibly halogen globes/lamps/bulbs.

[Sophon]

Wow a lot here

Dimmer switch:

• I am thinking of installing a dimmer switch in the main bedroom, but from what I have read they don't work with standard energy saving bulbs (LED and CFL). There are special such bulbs available, but apparently the dimmer switches may not work properly with these either.

  Does anyone have experience with dimmer switches and energy saving light bulbs here in Thailand?

• I am assuming that dimmer switches are connected the same way as standard switches, so that I will easily be able to switch back to a standard switch later, if the dimmer switch turns out to be more trouble than it's worth.

  Is that a correct assumption?

LED's can be dimmed, but you will need drivers, and 10V dc dimmers (IMO the way to go) not sure of availability inLOS

I think I will just use traditional bulbs for now.

Do you know if dimmer switches and standard switches are freely interchangeable without need for changing the wiring?

• Assuming that the live wire is black and the neutral is white, which colour(s) would you recommend for the three wires connecting the two switches?

  I am thinking I will just use black wire to make it clear, that they are all potentially live.

As I understand it the two two-way switches will be connected together L1 to L1, L2 to L2 and Common to Common. Incoming live will go to L1 and the live wire to the lamps will come from L2. Other than that the lamp will, of course, also be connected to the circuits neutral wire. Any of the three wires connecting the two two-way switches may at any time be live (depending on the switch positions).

Black. There are 2 ways methods to connect up 2 way switches, method 1 has live (feed) and switch line at one switch, method 2 has live at one switch and switch line at other), advise what you have

As of this moment I don't have anything. I will see what is available at the local shops.

Outlets with on/off switches:

• For the kitchen counter we want to have electric outlets with on/off switches. This would allow us to keep frequently used appliances without their own on/off switches such as the water kettle and rice cookers connected, instead of having to plug/unplug them every time we use them. The only brand I can find locally here in Lamphun/Chiang Mai are Chang (I have looked at the usual places such as Global, Thai Watsadu and Home Pro).

  Does anyone have good/bad experiences with switched outlets generally, and with the Chang brand in particular? Is it something I should avoid?

scheinder do a very good range, and available

I assume you mean Schneider? As mentioned, the only ones I have been able to find are Chang, can you tell me where to get Schneider?

Generally we will be using Panasonic, but none of the local building suppliers have Panasonic power outlets with switches and I am not sure they even produce one.

Double switch boxes:

• In a number of places I will have two light circuits controlled from the same switch box. The circuits will be on the same main circuit, so can use the same live and neutral. Splitting the live wire at the connection box at the top of the conduit (in the attic) would mean two live wires going to and from the two switches (four total), while splitting behind the switches would mean only one incoming live wire (three total). My guess is that the split should be in the top connection box.

  Where should the the live wire be split, at the switch box or at the top connection box?

try to avoid connection boxes.

Sorry, but I don't follow you. The confusion is probably caused by me using the wrong terminology, I am talking about the yellow 5 cm x 10 cm (or 10 x 10) boxes that go between the conduits. Should I have used "junction boxes" instead?

Thanks again.

Sophon

[Forkinhades]

Switches are inter changeable

Try to only do connections at light switches or lights, not in between.

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[Sophon]

Switches are inter changeable

Try to only do connections at light switches or lights, not in between.

Sent from my GT-I9300 using Thaivisa Connect Thailand mobile app

Sorry, but I still don't understand. The wires for e.g. a light circuit runs around the top of the wall in the attic. From there a dropper goes down to the light switch. Don't the dropper have to be connected to the main circuit wires at the junction box in the attic?

And in order for the main circuit to branch out to the different rooms of the house I don't see any way around having to split the circuit in a number of places, some of which have neither a switch or a light. As an example, this is how I imagine light circuit 1 to run:

I was thinking that the circuit would be split at the red cross. I guess the split could be at the light switch before that, but then I would have two sets of wires running parallel until the point were the circuit branches out, which in some areas would create problems with fitting the wires in the conduits.

Sophon

[Crossy]

No problem with using droppers, except that the joint is in a box which is possibly made inaccessible by the ceiling cladding.

Such a join would not be permitted under the UK rules unless it was made using a 'maintenance free' method (Wago connectors are such a method).

If the box is accessible from the attic space, no issue, just use a light sparky to access it.

The rule of only joining cables at switches, outlets or ceiling roses makes future maintenance and fault finding far, far easier and wires tend to be the same colour at both ends (I had that problem).

[bankruatsteve]

That's fine. Just make sure all connections are secure and in a box. A light switch only switches L, so there is no requirement to carry the N to the switch.

[Forkinhades]

A few years back I would have agreed with not taking neutrals to switches, it is commonplace in the UK now, and widely accepted with no regs against it.

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[Sophon]

No problem with using droppers, except that the joint is in a box which is possibly made inaccessible by the ceiling cladding.

Such a join would not be permitted under the UK rules unless it was made using a 'maintenance free' method (Wago connectors are such a method).

If the box is accessible from the attic space, no issue, just use a light sparky to access it.

The rule of only joining cables at switches, outlets or ceiling roses makes future maintenance and fault finding far, far easier and wires tend to be the same colour at both ends (I had that problem).

All boxes will be accessible via the attic, although some obviously more easily than others.

So if a understand you correctly, when bringing the live wire to a double switch, you would only bring one wire down and then split it at the switch box?

Sophon

[Sophon]

To update, I found some Häco power outlets with switches at the local electric specialist, so bought four of those. I also bought a dimmer switch, I never lived anywhere with dimmer switches before, so don't know if it's worth it having to use standard bulbs. But I will give it a try, and if not using the function much I will just replace the switch with a standard switch.

They also seem to have most of the wires I need, but unfortunately don't stock the 16 mm² green wires for the ground connection. So if anyone have any idea where to buy wire by the meter, please let me know.

Thanks again to everyone.

Sophon

[Forkinhades]

A typical switch would be:

Live In

Live Out

Switch line

Earth

In LOS you will find that the sparky will also take the neutral to the switch.

If not IMO the neutral should be taken the light.

It just depends where you want less wires.

Neutrals at switches are good for maintenance, and are easily accessible.

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[Crossy]

Just use black for the ground to the rod, there is no regulation requiring that it's green, put some tape or heatshrink on the ends if you wish.

On the light switches, yes one live dropper split in the switch box is the way to go, drop a neutral as well and insulate the end, could be useful if you install remote switches or even an outlet in the switch box.

[Sophon]

A typical switch would be:

Live In

Live Out

Switch line

Earth

In LOS you will find that the sparky will also take the neutral to the switch.

If not IMO the neutral should be taken the light.

It just depends where you want less wires.

Neutrals at switches are good for maintenance, and are easily accessible.

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But all this is about later maintenance, isn't it?

I can understand that bringing the wires to the switches/outlets give easier access later and possibly saves you a trip climbing around the attic. But it also increases the number of wires in the conduits and wire nuts in the (relatively) limited space of the switch/outlet box. A standard power outlet would have six wires in the conduit and three wire nuts plus a "jumble of wires" in the outlet box. And if you have a combined switch and power outlet box, then you would quickly exceed the capacity of the conduit and would have to put in an extra conduit.

To me (as a non-electrician) it gives a much cleaner picture if the wires are split at the junction boxes in the attic. That way you have fewer places with "redundant" wires (same wire going in both directions in a conduit), and you don't have wire nuts crammed in behind the switches/outlets in the switch/outlet box. But as said, I understand that this means that later maintenance will require crawling around in the attic place.

Sophon

[Sophon]

Just use black for the ground to the rod, there is no regulation requiring that it's green, put some tape or heatshrink on the ends if you wish.

On the light switches, yes one live dropper split in the switch box is the way to go, drop a neutral as well and insulate the end, could be useful if you install remote switches or even an outlet in the switch box.

I hadn't heard of remote switches before, so had to do some Googling. I doubt that I will find a need for those.

If were to drop a neutral and later use it for installing a power outlet in the switch box, wouldn't that put the outlet on a light circuit and therefore on the wrong circuit and breaker. While probably safe if not plugging anything to demanding into the outlet, that would offend my need for order in the universe

Sophon

[Forkinhades]

Just to add there are many ways to do this, all have their pros and cons. Its up to you to decide.

Many cables at the switch is a con, but the pro is that you only need a screwdriver to access the joints.

Joints in ceiling void 'junction' boxes reduce cables at switchboxes, but are not easily maintained, steps and access is needed.

A good electrician will wire with NO junction boxes in ceiling void. The joins will either be at the lightswitch or lights as previously suggested.

If you have a thai sarky to do this, I would be leaning towards just let him do what he knows best, but be very watchful.

Up to you as they say.

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[Sophon]

Just to add there are many ways to do this, all have their pros and cons. Its up to you to decide.

Many cables at the switch is a con, but the pro is that you only need a screwdriver to access the joints.

Joints in ceiling void 'junction' boxes reduce cables at switchboxes, but are not easily maintained, steps and access is needed.

A good electrician will wire with NO junction boxes in ceiling void. The joins will either be at the lightswitch or lights as previously suggested.

If you have a thai sarky to do this, I would be leaning towards just let him do what he knows best, but be very watchful.

Up to you as they say.

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How do you wire with no junction boxes? The circuits comes from the main distribution board in conduits and drops down to e.g. a switch box, how do you make the drop without having a junction box that connects the conduit the main circuit runs in and the conduit leading to the switch box (plus the conduit continuing the main circuit to the next location)?

Edit: Or did you just mean with no connections in the attic?

To try to take maintenance out of the equation for a second. Downstairs is a raised crawl space with a ceiling height of only about 2 meter, and because of the limited ceiling height there is no suspended ceiling. That means that the "attic" junction boxes are actually embedded in the walls at a height of approximately 1.6 meter, and are freely accessible in the same way that the switch and outlet boxes are. In this scenario, would you still lead the main circuit down to the switch, or only the dropper?

Sophon

[Forkinhades]

Trust me it can be done. If you need to install junction boxes try not to make them connection boxes.

I will do a diagram when I get to my laptop.

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[Crossy]

Exactly Forky, there will be boxes in the conduit, just no cable joints in them, standard UK practice.

I wish our sparks had done it that way, I wondered why he'd used all my yellow Wagos so quickly, every box has a birds-nest of joints not necessarily all wires of the same colour

[Sophon]

Trust me it can be done. If you need to install junction boxes try not to make them connection boxes.

I will do a diagram when I get to my laptop.

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I trust you when you say it can be done, I am just trying to understand how. I am on a sharp learning curve here.

Thanks for your help.

Sophon

[Crossy]

To be honest and pragmatic, unless you are going to do it yourself, find a recommended local sparks (now there is a challenge).

Give him some ground rules (one length where possible, no taped joints, no shared neutrals) and let him get on with it.

Inspect often (he will forget your rules very quickly) and get him to fix transgressions immediately.

Make sure you test everything works properly before the ceiling goes up.

[Sophon]

To be honest and pragmatic, unless you are going to do it yourself, find a recommended local sparks (now there is a challenge).

Give him some ground rules (one length where possible, no taped joints, no shared neutrals) and let him get on with it.

Inspect often (he will forget your rules very quickly) and get him to fix transgressions immediately.

Make sure you test everything works properly before the ceiling goes up.

The sparky will be our neighbour, and while I will not do it myself I will probably act as his assistant helping with pulling cables etc. That will help with keeping an eye on what is going on, without it being too obvious that's what I am doing. He is retired and have to spend time on his own rice fields and longan trees, so I will do whatever I can. I have already done all the recessing of conduits and the Square D box, and am now assembling the conduits in the attic space. That's why I need to know and understand how everything fits together, so that we have all the conduits we need when we start with the electric stuff.

What do you mean by one length where possible"?

Good point about testing everything before the ceiling goes up. Would it be normal to test;

• Each new sub-circuit (light or plug)?
• Each circuit when it's finished?
• Everything when it's completed?

Thank you to everyone for the input, I have learned a lot during this process (going from knowing nothing about electrics to at least having a rudimentary understanding). I hope this topic have also been of help to others.

Sophon

[Forkinhades]

With current (UK) regs you do not need conduits, as your curcuits will be pritected by RCBO. but IMO needed for switch drops, and sockets.

The power is easy as you just go point point.

With lighting you need to determine where your feed goes, either to the switch (which is what they seem to do in LOS) which will have a neutral. Or to your light, where your switch will not have a neutral.

Diagrams to follow, out on site at present.

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[jonnyscot]

Hi sophon good luck with your build, I'm plodding away on our build which is I think just past the halfway stage, wife's getting the electrician round this week sometime, so that'll be an adventure

whilst taking any technical electrical advice from me may seriously damage your health, haha,, just something I thought to mention, maybe you've already seen them, but in our local home pro they have some very nice looking LED lights that come supplied with remote dimmer switches, I'm thinking of buying a couple of them myself for our house, they're not cheap mind you varying from 3500 to 5000 baht, but nice looking for the living areas

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[Crossy]

Hi sophon good luck with your build, I'm plodding away on our build which is I think just past the halfway stage, wife's getting the electrician round this week sometime, so that'll be an adventure

whilst taking any technical electrical advice from me may seriously damage your health, haha,, just something I thought to mention, maybe you've already seen them, but in our local home pro they have some very nice looking LED lights that come supplied with remote dimmer switches, I'm thinking of buying a couple of them myself for our house, they're not cheap mind you varying from 3500 to 5000 baht, but nice looking for the living areas

Interesting (and ouch on the price), can you post photos if you get them please?