Need advice for domestic instal in Thailand

[Thai Amateur]

Hi,
First let me just say that I am not an electrician although in the past I've done the usual garage and shed wiring without having any residual issues. Second my apologies for such a long post.
However, I am now involved with something a bit bigger than a garden shed.
I am building my own bungalow and am just trying to finalise the layout of the electrics. Before anyone shouts - my big problem is that I live in Thailand and there is no code applicable to electrical wiring and from everything I've seen the professional level is not particularly high. There aren't even building inspectors to come round and check what you are building conforms with the plans let alone fits any criteria.
Given that my current house has earth cabling (in parts) but no actual ground I decided it would be a lot better if I actually tried to conform with UK regs as far as I could. So I've been having to browse the web and usually finished up somewhere in this forum.
My reason for this post is to try to get some level of confirmation to what I propose to do.
At this stage I am just listing summary points.
Electricity Supply.

1. 1. 1. Meter is mounted on a concrete post in the road. Distance to consumer unit(s) approx 25 metres.
         
      2. Intend to use 16mm cable but will have to make sure the CU can take it.
         
         
      3. No earth included with supply.

Proposed layout.

1. 1. 1. 2 x 2 metre earth rods set 1 metre apart. Earth cable to be 10mm.
         
      2. Lighting circuits to be 2.5 mm with 1.5mm earth. Earth is mainly for ceiling and wall fans as I have not yet seen a ceiling light with an earth in Thailand.
         
      3. Main circuits to be 4.5mm with earth (radial).
         
      4. Air Con units are rated as less than 4kw but I have allowed one circuit for each (4.5mm with earth).
         
      5. Cooker is rated at 6 kw. Is 4.5mm cable big enough or should I use 6mm?
         
      6. Shower rooms to have water heaters rated at 6kw (max. Again is 4.5 mm cable big enough?
         
         
      7. Kitchen is 3.5m x 3.5 m. I am installing 4 sets of 4 sockets (mainly because I don't know what appliances will be used in what part of the kitchen apart from fridge and washing machine). I am thinking about installing a 2.5 mm ring main but again should I use 4.5mm in a ring or radial.
         
      8. The air cons (5) and water heaters (2) will all have separate circuits with 4.5 mm + earth.
         
      9. 2 lighting circuits.
         
      10. 6 main circuits.
          
      11. Total = 15 circuits.

I've checked cable sizes for voltage drops using different calculators from the web which is one of the reasons I have so many main circuits. Anyway I think too many circuits will be better than possibly overloading somewhere.
I could possibly squeeze these circuits into 1 consumer unit by changing the cable layout but would prefer to use 2. Both to allow for any future changes and to retain power in parts of the house should there be an issue in one of the units.

Consumer Units. (Apologies but this is where I do get a bit confused).

1. 1. 1. Power supply from meter via a 100 (or 80?) amp fused power switch into a Henley box.
         
      2. Loads to be split (and balanced) between each unit to allow power in case of issues. e.g. 1 light circuit to each unit.
         
      3. MCBs – Type B – 32amp on cooker, water heaters and main circuits. 20 amp on air cons, 6 amp on lighting and fans.
         
      4. Consumer units- 2 x 10 (possibly 12) way dual 63 amp RCD.
         
      5. RCBOs (63A/30mA) fitted on each side (4) of the consumer units.

I realise all this is very amateurish when put before experienced tradesmen but I'm sort of caught between a rock and a hard place.

 

[Engineer54]

Yet again – many thanks for all the input. Feel as though I'm beginning to get somewher now.

LOL - Just burnt out my SDS hammer drill. Was going to buy a new one anyway. I can put the rods next to the building wall as I haven't laid the outside path yet. I'll then bury the cable under the path and also make sure I leave an access to the rods themselves. I'll check at the builders' merchants as to maximum length of rod I can find. I think I also saw joints there but can't be sure at the moment.

No, that is the worst place to site an earth electrode keep at least a metre or more, away from any buildings walls. You can run the buried earth cable in PVC conduit back into the house

You shouldn't need more than 2 lighting circuits, (unless this is a very big house). Most ceiling/wall fans are around just 60 to 80W so can easily be supplied via the lighting circuits or if you wish a separate circuit for these fans.


Just that the length of the circuits themselves pushed the cable size up to 2.5mm. It is just as easy to put in 4 circuits as 2 and I'll have space on the CU's.


As i said, i doubt if the length of your circuits within a standard sized bungalow will undully affect cable sizing. 1.5 mm should be more than ample for your requirements. Up to you, but totally unnecessary to have 4 lighting circuits here in my opinion

Just about everything sold out here is 220v rated. Sockets themselves take round or flat pin terminals for live and neutral with a round pin for the earth.

OK you know more than me as to whats available for domestic's in Thailand these day's!!

Design of sockets and switches here seems pretty neat and tidy. Switches are the same size as the sockets so everything could fit into the same plate. It's just that the quality varies significantly. One issue to look for is that they come in 2 different sizes so will have to make sure I get the right size to fit the mounting plates.

Can you post photo's or catologue pictures of the wall accessoiries you intend using, they sound like American in many respects but want to be sure. I don't and never have liked the standard American wall accessories, or the method of wiring and connection.

Yes – that's right. 2 sets are on the back wall – 1 primarily for the washing machine and the other for the fridge. There will a work surface between the 2 so I've allowed for occupants to use whatever appliances they like without having cables lying about everywhere.
1 other set covers the main working surface and the final one covers the work surface between the kitchen and dining area (open plan).

Again better to have controlling switches above the worktop to control socket outlets below worktop level, for appliances such as built in/floor standing washing machines, tumble dryers, dishwashers etc, though i wouldn't put a control switch in for the fridge/freezer just in case some fool switches it off....lol!!

Will do. I hadn't planned on switching the AC units though. Just running them directly from the CU. They're remote controlled so would be left switched on all the time anyway. Is this important?

What type of AC's are you going to be using, split system or wall bangers (single through the wall AC unit)?? The usual connection to such domestic AC's is either a Switched fuse connection unit (no such thing in American wiring systems) or a switched socket outlet, (that'll be one of those double socket outlets and a switch in the large American back boxes, to my knowlege they don't do switched socket outlets). On split unit AC's, the external condensing unit, will also need a means of DP isolation. Yes it is important!!


Found an online site here that does Wago stuff so that's on problem sorted at least.

Yep the Wago connectors are pretty good!!!

Would like to but there are a couple of problems. First is that I live in a place called Udon Thani. It's a big town up in the North East - long way from the sea. Plenty of construction going on but I think that any really good electrician would be off to Bangkok or overseas to get the money.
The other problem is that my father-in-law is an “electrician”. He worked for 14 years in Saudi and is the guy who installed the electrics in my own house. No earth, etc.
He obviously wants to get involved as I will have to pay him. We don't get on and if I employ someone else it will cause (another - LOL) family feud.
That's one of the main reasons that I'm trying to dot the i's and cross the t's before I actually start wiring.

Maybe that's a problem for you, but at the end of the day house electric's is not as easy as many would like to think!! How are you intending to test all this wiring work, as that's going to be just as important as the actual wiring itself, especially as we will also be considering RCD devices at the CU end of the installation.
Safety first is always the best way to go

Construction is concrete frame with brick/block infill. Actually put up cavity walls. Brickies had never seen them before and I( had to keep checking that they put in the wall ties.
Steel framed roof – Termites can't eat steel.

I thought it would be concrete framed with block/brick infill!! Hope you can get DPC for the infill walls over there in Thailand, cause when it rains it rains in bucket loads in that part of the world!! Our project site in Zhuhai is like a bloddy quagmire at the moment!! lol!!

 

[Thai Amateur]

What you ''NEED'' to know, is the Maximum current or KW, the supply company are or will be supplying, not the voltage.
Electric Company says 30 Amp supply. My house (next to new one) must have the same and it has 2 x CUs each with 63A main. 3OA equates to 7kw so how can that supply the power for even the 3 ACs I currently have in the house let alone the water heaters?
LOL - Just burnt out my SDS hammer drill. Was going to buy a new one anyway. I can put the rods next to the building wall as I haven't laid the outside path yet. I'll then bury the cable under the path and also make sure I leave an access to the rods themselves. I'll check at the builders' merchants as to maximum length of rod I can find. I think I also saw joints there but can't be sure at the moment.

No, that is the worst place to site an earth electrode keep at least a metre or more, away from any buildings walls. You can run the buried earth cable in PVC conduit back into the house
That's no problem I can install in the same trench as the water supply/main drain – PVC pipes. I'm going to test drive a 2 metre rod in the next couple of days to see if there is a problem getting down that far. Builders Merchants have 4 metre rods so the only problem with those will be getting high enough to hit the tops.You shouldn't need more than 2 lighting circuits, (unless this is a very big house). Most ceiling/wall fans are around just 60 to 80W so can easily be supplied via the lighting circuits or if you wish a separate circuit for these fans.


Just that the length of the circuits themselves pushed the cable size up to 2.5mm. It is just as easy to put in 4 circuits as 2 and I'll have space on the CU's.


As i said, i doubt if the length of your circuits within a standard sized bungalow will undully affect cable sizing. 1.5 mm should be more than ample for your requirements. Up to you, but totally unnecessary to have 4 lighting circuits here in my opinion

Just about everything sold out here is 220v rated. Sockets themselves take round or flat pin terminals for live and neutral with a round pin for the earth.

OK you know more than me as to whats available for domestic's in Thailand these day's!! Design of sockets and switches here seems pretty neat and tidy. Switches are the same size as the sockets so everything could fit into the same plate. It's just that the quality varies significantly. One issue to look for is that they come in 2 different sizes so will have to make sure I get the right size to fit the mounting plates.

Can you post photo's or catologue pictures of the wall accessoiries you intend using, they sound like American in many respects but want to be sure. I don't and never have liked the standard American wall accessories, or the method of wiring and connection.

Type of thing we have out here. Of course I'll have to get matching items. Face plates come with a back plate for mounting the switches/sockets. They just click in place.


Yes – that's right. 2 sets are on the back wall – 1 primarily for the washing machine and the other for the fridge. There will a work surface between the 2 so I've allowed for occupants to use whatever appliances they like without having cables lying about everywhere.
1 other set covers the main working surface and the final one covers the work surface between the kitchen and dining area (open plan).

Again better to have controlling switches above the worktop to control socket outlets below worktop level, for appliances such as built in/floor standing washing machines, tumble dryers, dishwashers etc, though i wouldn't put a control switch in for the fridge/freezer just in case some fool switches it off....lol!!

Will do. I hadn't planned on switching the AC units though. Just running them directly from the CU. They're remote controlled so would be left switched on all the time anyway. Is this important?

What type of AC's are you going to be using, split system or wall bangers (single through the wall AC unit)?? The usual connection to such domestic AC's is either a Switched fuse connection unit (no such thing in American wiring systems) or a switched socket outlet, (that'll be one of those double socket outlets and a switch in the large American back boxes, to my knowlege they don't do switched socket outlets). On split unit AC's, the external condensing unit, will also need a means of DP isolation. Yes it is important!!
ACs are split type with condensing unit outside. Definitely have to sort this out then because every AC I've seen out here just gets }hot wired}.

Found an online site here that does Wago stuff so that's on problem sorted at least.

Yep the Wago connectors are pretty good!!!

Would like to but there are a couple of problems. First is that I live in a place called Udon Thani. It's a big town up in the North East - long way from the sea. Plenty of construction going on but I think that any really good electrician would be off to Bangkok or overseas to get the money.
The other problem is that my father-in-law is an “electrician”. He worked for 14 years in Saudi and is the guy who installed the electrics in my own house. No earth, etc.
He obviously wants to get involved as I will have to pay him. We don't get on and if I employ someone else it will cause (another - LOL) family feud.
That's one of the main reasons that I'm trying to dot the i's and cross the t's before I actually start wiring.

Maybe that's a problem for you, but at the end of the day house electric's is not as easy as many would like to think!! How are you intending to test all this wiring work, as that's going to be just as important as the actual wiring itself, especially as we will also be considering RCD devices at the CU end of the installation.
Safety first is always the best way to go
I'll ask around the local ex-pat sites although I still think I'll need to know a lot more as the peop0le I'll be asking probably won't be that technical anyway.
I've just bought a Class III 600 volt multimeter. It's Kyoritsu model 2017. I've had a quick look round the web on how to test but some of the instructions look a bit basic. Will keep looking but realise that I'll have to take my time to test the whole thing properly.

Construction is concrete frame with brick/block infill. Actually put up cavity walls. Brickies had never seen them before and I( had to keep checking that they put in the wall ties.
Steel framed roof – Termites can't eat steel.
I thought it would be concrete framed with block/brick infill!! Hope you can get DPC for the infill walls over there in Thailand, cause when it rains it rains in bucket loads in that part of the world!! Our project site in Zhuhai is like a bloddy quagmire at the moment!! lol!!
LOL - No DPC out here. Never seen any. Get over the problem by making the wall footings 50cm deep and infilling with really well compacted earth. Locals then build off the footings and put the slab in after but I've put the slab across the whole area – edge to edge – and then built the walls off that. Means that the wall base is 60 cm above ground. No problems with damp at all in my own house. We don't have monsoons in Northern Thailand just 5 months when it rains quite heavily. No flooding though and the surface water disappears quite quickly.
Also means that I won't have a problem with the slab settling even if the infill does drop a bit.

 

[Engineer54]

Electric Company says 30 Amp supply. My house (next to new one) must have the same and it has 2 x CUs each with 63A main. 3OA equates to 7kw so how can that supply the power for even the 3 ACs I currently have in the house let alone the water heaters?

The main switches do not usually have any form of protection they are just DP switches for isolation purposes, that are able to carry 63A. Think you'll find that if you require more than 7KW, then you pay a higher installation charge for a 3 phase supply and higher monthly (or whatever) standing charges. You'll be surprised what a 30A supply can accommodate in a domestic setting, ''Diversity'' is a wonderful thing. For a start AC's are not working at full capacity all the time, they like many other appliances work will be switching on and off via thermostat's and the like. Have you had any problems with your house, where the supply companies main cut-out fuse has blown?? lol!!

That's no problem I can install in the same trench as the water supply/main drain – PVC pipes. I'm going to test drive a 2 metre rod in the next couple of days to see if there is a problem getting down that far. Builders Merchants have 4 metre rods so the only problem with those will be getting high enough to hit the tops.

For ease of installation maybe better to purchase 2 X 2m rods and drive them in one at a time. Just needs a coupler on the first rod that you can screw the second rod onto. Best install in a position where you will be watering during the hot summer months, to keep the soil moist. Dried up soil is a killer for any earth electrode as the soil needs to be in constant moist contact with the earth rod. And by the sound of it you have very free draining soil where you are.

Type of thing we have out here. Of course I'll have to get matching items. Face plates come with a back plate for mounting the switches/sockets. They just click in place.

Well the flat 3 pin American style that is shown in this dual plug top outlet is the Yank 125 volt configuration which is not suitable for 220 volt operation. I can't think of any other international plug top design that matches the 3 pin round 22O V pins shown above in your picture, only an unearthed two pin design. So maybe a little further investigation is needed here...

ACs are split type with condensing unit outside. Definitely have to sort this out then because every AC I've seen out here just gets }hot wired}.

Well you did say you want the electrical installation installed correctly!! lol!! Make sure the condensing units external switches are suitably IP rated (IP 56 min)

I've just bought a Class III 600 volt multimeter. It's Kyoritsu model 2017. I've had a quick look round the web on how to test but some of the instructions look a bit basic. Will keep looking but realise that I'll have to take my time to test the whole thing properly.

Unfortunately, a simple multimeter will be not suitable for the majority of the electrical test requirements to your property. The test instruments you will require is a 500V Insulation tester, a Earth Loop Impedance tester, and a Residual Current Device tester. Maybe you will be able to locally hire them, but you'll still need someone who know's how to use them....

LOL - No DPC out here. Never seen any. Get over the problem by making the wall footings 50cm deep and infilling with really well compacted earth. Locals then build off the footings and put the slab in after but I've put the slab across the whole area – edge to edge – and then built the walls off that. Means that the wall base is 60 cm above ground. No problems with damp at all in my own house. We don't have monsoons in Northern Thailand just 5 months when it rains quite heavily. No flooding though and the surface water disappears quite quickly.
Also means that I won't have a problem with the slab settling even if the infill does drop a bit.

Ok i think i've got the idea, you're building your bungalow on a ''Raft'' type foundation that has it's top face 60cm above FGL. I wasn't thinking along the lines of monsoons, we don't have them here either. Just that in these tropical and semi tropical countries when it rains it rains, and normally much heavier than what we are used too in Europe...

Can you post a photo of the type of Consumer unit, you are intending to use in your bungalow to supply your electrical circuits??

 

[Thai Amateur]

et again many thanks for your interest. I surely would have made quite a mess without it.


Electric Company says 30 Amp supply. My house (next to new one) must have the same and it has 2 x CUs each with 63A main. 3OA equates to 7kw so how can that supply the power for even the 3 ACs I currently have in the house let alone the water heaters?
The main switches do not usually have any form of protection they are just DP switches for isolation purposes, that are able to carry 63A. Think you'll find that if you require more than 7KW, then you pay a higher installation charge for a 3 phase supply and higher monthly (or whatever) standing charges. You'll be surprised what a 30A supply can accommodate in a domestic setting, ''Diversity'' is a wonderful thing. For a start AC's are not working at full capacity all the time, they like many other appliances work will be switching on and off via thermostat's and the like. Have you had any problems with your house, where the supply companies main cut-out fuse has blown?? lol!!
No problems with the main circuits whatever. We do use CFL lamps here but they don't last 3 years! I think I might have some sort of problem with the downstairs lighting circuit but changing it will be a nightmare. Suspended ceiling and there is a concrete slab floor above.
Electricity company said 3 phase would be 15 Amps. Guy up the road installed 3 phase and it cost him a fortune - [FONT=Liberation Serif, serif]₤[/FONT][FONT=Liberation Serif, serif]2,500 against [/FONT][FONT=Liberation Serif, serif]₤[/FONT][FONT=Liberation Serif, serif]100 for single phase.[/FONT]
That's no problem I can install in the same trench as the water supply/main drain – PVC pipes. I'm going to test drive a 2 metre rod in the next couple of days to see if there is a problem getting down that far. Builders Merchants have 4 metre rods so the only problem with those will be getting high enough to hit the tops.
For ease of installation maybe better to purchase 2 X 2m rods and drive them in one at a time. Just needs a coupler on the first rod that you can screw the second rod onto. Best install in a position where you will be watering during the hot summer months, to keep the soil moist. Dried up soil is a killer for any earth electrode as the soil needs to be in constant moist contact with the earth rod. And by the sound of it you have very free draining soil where you are.
Have to find a coupler then or make one up. Position will be quite good as it is right under the roof overhang so any rain will drop into that area. Plus it is at the edge of the “lawn” so should get watered fairly regularly.
Type of thing we have out here. Of course I'll have to get matching items. Face plates come with a back plate for mounting the switches/sockets. They just click in place.
Well the flat 3 pin American style that is shown in this dual plug top outlet is the Yank 125 volt configuration which is not suitable for 220 volt operation. I can't think of any other international plug top design that matches the 3 pin round 22O V pins shown above in your picture, only an unearthed two pin design. So maybe a little further investigation is needed here..
Plugs and switched are both rated 16A / 250V and they are the standard out here. Haven't had any problems in my house with the fixed installations. Extension leads are another problem though.
ACs are split type with condensing unit outside. Definitely have to sort this out then because every AC I've seen out here just gets }hot wired}.
Well you did say you want the electrical installation installed correctly!! lol!! Make sure the condensing units external switches are suitably IP rated (IP 56 min)
Will do.
I've just bought a Class III 600 volt multimeter. It's Kyoritsu model 2017. I've had a quick look round the web on how to test but some of the instructions look a bit basic. Will keep looking but realise that I'll have to take my time to test the whole thing properly.


Unfortunately, a simple multimeter will be not suitable for the majority of the electrical test requirements to your property. The test instruments you will require is a 500V Insulation tester, a Earth Loop Impedance tester, and a Residual Current Device tester. Maybe you will be able to locally hire them, but you'll still need someone who know's how to use them....
No chance of hiring these. Rental places are pretty good for the normal building stuff but nothing technical. I can buy these (knocks a bit more of a hole in my budget - lol) but I like having tools about on the basis that if you've used them once then you're likely to need them again. I have to run some sort of wiring up the garden in due course so would need stuff for that.
As you say I'll need to find someone to use them properly. It's possible that my wife's father has some idea but I don't want to rely on him too much.
I've asked round the local ex-pat sites about a good electrician so might get a nibble or two from there.
LOL - No DPC out here. Never seen any. Get over the problem by making the wall footings 50cm deep and infilling with really well compacted earth. Locals then build off the footings and put the slab in after but I've put the slab across the whole area – edge to edge – and then built the walls off that. Means that the wall base is 60 cm above ground. No problems with damp at all in my own house. We don't have monsoons in Northern Thailand just 5 months when it rains quite heavily. No flooding though and the surface water disappears quite quickly.
Also means that I won't have a problem with the slab settling even if the infill does drop a bit.
Ok i think i've got the idea, you're building your bungalow on a ''Raft'' type foundation that has it's top face 60cm above FGL. I wasn't thinking along the lines of monsoons, we don't have them here either. Just that in these tropical and semi tropical countries when it rains it rains, and normally much heavier than what we are used too in Europe...
LOL – we have some pretty good thunderstorms in the windy season. Just coming the end of the rainy season and we've had a lot more rain than last year. Our fish pond is almost up to the overflow level. It's about 18 metres square and 3 metres deep and was about 8ocm at the beginning of the season.

Can you post a photo of the type of Consumer unit, you are intending to use in your bungalow to supply your electrical circuits??

Something like this. It's an MK 63A and compatible with 17th Edition. I will probably have to change some of the MCBs to suit my installation though.

 

[Engineer54]

No problems with the main circuits whatever. We do use CFL lamps here but they don't last 3 years! I think I might have some sort of problem with the downstairs lighting circuit but changing it will be a nightmare. Suspended ceiling and there is a concrete slab floor above.
Electricity company said 3 phase would be 15 Amps. Guy up the road installed 3 phase and it cost him a fortune - ₤2,500 against ₤100 for single phase.

As i said, shouldn't be too much of a problem having a 30A supply, so long as you don't go overboard and start switching everything on for any length of time!! In France, i think the supply starts at 15A and the more Amp's you want supplied the higher the cost installation and monthly costs. UK is quite unique in Europe, in that a standard supply can be anything between 60, 80, 100A on a single phase supply and costs nothing to upgrade between those values!! lol!!

Have to find a coupler then or make one up. Position will be quite good as it is right under the roof overhang so any rain will drop into that area. Plus it is at the edge of the “lawn” so should get watered fairly regularly.

Earth rods of 5/8'' and over, come with threads at each end, a made for purpose coupler fits these threads, i doubt if you can make one up. Pretty sure if they sell purpose made earth rods then they will also supply couplers and driving heads that fit the coupler for driving purposes!!

Plugs and switched are both rated 16A / 250V and they are the standard out here. Haven't had any problems in my house with the fixed installations. Extension leads are another problem though.

I couldn't tell you, the projects i have worked on in Thailand used German (DIN) Shucko type socket outlets, throughout. Which wouldn't fit the wall plates you posted up, as the earth is in the form of a scraping earth, between plugtop and wall socket.

No chance of hiring these. Rental places are pretty good for the normal building stuff but nothing technical. I can buy these (knocks a bit more of a hole in my budget - lol) but I like having tools about on the basis that if you've used them once then you're likely to need them again. I have to run some sort of wiring up the garden in due course so would need stuff for that.
As you say I'll need to find someone to use them properly. It's possible that my wife's father has some idea but I don't want to rely on him too much.
I've asked round the local ex-pat sites about a good electrician so might get a nibble or two from there.

You can purchase a single MFT (Multi Function Tester) that will be able to perform all the required installation tests, or they come in separates Check out the forums sponsor at ''test-meter.co.uk'' which will give you some idea of cost in the UK....
Let's hope you can locate a Western Expat electrician that's fairly local to you're location, it'll save you a lot of time, worry and possibly money!! lol!!

 

[Engineer54]

This link will give you an idea of what i'm talking about as far as rod couplers and driving heads...

http://www-public.tnb.com/eel/docs/furse/Total_Solution_TSC-0912_Threaded_Rod.pdf

One of these would be a good idea, they both protect cable and rod connection and identify the rods position that can get well and truly lost over the years!! lol!!

http://www-public.tnb.com/eel/docs/furse/Total_Solution_TSC-0912_Earth_Inspection_Pits.pdf

 

[Thai Amateur]

Many thanks yet again Engineer 54.


So this is my latest proposed installation.

1. Main Supply into a 80A fused switch mounted in a box.
   
2. Then L and N into (2) 2 way commoning blocks mounted in a box.
   
3. These to be mounted in the roof space near the loft access.
   
4. Each set of L & N then to run into an MK 16way split consumer unit. Main switch 63A.
   
5. Earth Rods to be 4 metre deep with minimum spacing of 4 metres. Set about 1.2 metre from house wall. Managed to get one rod in to 2 metres so far but not rushing it. Really expensive – 2 metre x 5/8 rods cost about £65 each.
   
6. Earth cable to be 10mm. Run into 2 way commoning block and then into each consumer unit.
   
7. 2 No. lighting circuits including Ceiling and Wall Fans. Cable to be 1.5 mm. Ceiling lights will be downlighters that do not have an earth connection. MCB = 6A.
   
8. 5 No. Air Con circuits – 1 for each Air Con. Cable to be 4.5 mm. MCB = 20A.
   
9. 1 No. Cooker circuit. Cable to be 6 mm. 2 Pole switch. MCB = 32A.
   
10. 2 No. Shower circuits. Cable to be 4.5 mm. 2 pole switch. MCB = 32A.
    
11. 6 No. Main circuits. Cable to be 4.5 mm. MCB = 20A.
    
12. 1 No. external supply to water pump and external socket. Feed will run into small consumer unit with RCBO. MCBs to be 10A.
    
13. Cable joints to be Wago connectors. Only lighting circuits to have joins (switches).
    
14. All cables to include earth wire.
    
15. Sockets and accessories to be rated at least 240V / 16A.

Total number of MCBs is 17 which seems high for a relatively small bungalow but It helps to keep things simple.


I've got some contacts for what should be good electricians – from supply company's inspection dept or local skilled labour centre.

 

[Engineer54]

Many thanks yet again Engineer 54.

There is a Thanks button at the bottom left of every post, ...lol!!


So this is my latest proposed installation.


1/ Main Supply into a 80A fused switch mounted in a box.

Could be rated smaller, say 40A or 63A max, seeing as you only have a 30A supply into the house. Either way, the suppliers cutout fuse is going to operate before yours will. lol!!

2/ Then L and N into (2) 2 way commoning blocks mounted in a box.
3/ These to be mounted in the roof space near the loft access.
4/ Each set of L & N then to run into an MK 16 way split consumer unit. Main switch 63A.

5/ Earth Rods to be 4 metre deep with minimum spacing of 4 metres. Set about 1.2 metre from house wall. Managed to get one rod in to 2 metres so far but not rushing it. Really expensive – 2 metre x 5/8 rods cost about £65 each.
6/ Earth cable to be 10 mm. Run into 2 way commoning block and then into each consumer unit.

You may only need one 4m earth rod, but the only way you would know that, is if you test it with an ELI TESTER (see earlier post) If at all possible try and increase the distance between rods to 1.5 times the driven depth, (eg 6m). It is sometimes useful to excavate a 1m deep X .5m hole then drive the rod in the ground and backfill/compact. If two rods are being used, link the two rods out with the 10 mm cable and take a single 10mm earth conductor back to the CU's. Are you using an S D type drill (set to rotation off) ?? It will make short work of driving those rods in the ground and make life a lot easier than a club or sledge hammer....

7/ 2 No. lighting circuits including Ceiling and Wall Fans. Cable to be 1.5 mm. Ceiling lights will be downlighters that do not have an earth connection. MCB = 6A.

Connect the earth cable (CPC) at the ceiling lights into a connector, for future use.

8/ 5 No. Air Con circuits – 1 for each Air Con. Cable to be 4.5 mm. MCB = 20A.
9/ 1 No. Cooker circuit. Cable to be 6 mm. 2 Pole switch. MCB = 32A.
10/ 2 No. Shower circuits. Cable to be 4.5 mm. 2 pole switch. MCB = 32A.

11/ 6 No. Main circuits. Cable to be 4.5 mm. MCB = 20A.
How many socket outlets are you going to connect to each of these circuits, you shouldn't need 6 socket outlet circuits. Say 1 circuit for the all the bedrooms, 1 circuit for the lounge and dining room. 2 circuits for the Kitchen.... Total 4 radial circuits should be more than ample for your needs.

12/ 1 No. external supply to water pump and external socket. Feed will run into small consumer unit with RCBO. MCBs to be 10A.

If the supply cable from the main CU is supplied from a protected circuit (RCD) then no need for a RCD at the small CU. The two RCD's will not discriminate with each other, e.g. either or both RCDs will trip in the case of an fault fault... If supply cable is going underground then the cable should be Steel Wire Armour (SWA) cable.


13/ Cable joints to be Wago connectors. Only lighting circuits to have joins (switches).
14/ All cables to include earth wire.
15/ Sockets and accessories to be rated at least 240V / 16A.


Total number of MCBs is 17 which seems high for a relatively small bungalow but It helps to keep things simple.

Up to you really, but that sounds like an awful lot of circuits to me!!!

I've got some contacts for what should be good electricians – from supply company's inspection dept or local skilled labour centre.

That sounds like a very good idea, you really do need a qualified electricians input into this installation. Just make sure they or he, understands that your standards/requirements are higher than those they may be used to for a domestic installation!! lol!!

 

[HandySparks]

So this is my latest proposed installation.

1. Main Supply into a 80A fused switch mounted in a box.
2. Then L and N into (2) 2 way commoning blocks mounted in a box.
3. These to be mounted in the roof space near the loft access.
4. ...

I generally agree with what E54's said in the post above.

I would try to locate any switchgear somewhere more readily accessible than the loft. It makes it more likely to be found by someone unfamiliar with the installation and it's quicker to get at if needed in an emergency. Try and keep all this sort of stuff near the CUs if possible.

 

[Thai Amateur]

Managed to get the earth rods in at last. Did it in the end by driving a steel tube down a few inches at a time. Took a while but had to drive through some pretty tough stuff.
End of the rainy season and the water level is only a metre below the surface. I'll get the earth checked when we finish the installation but I'll also test it again next April when evrything has dried out.
Almost finished the chasing. Is this one of the reasons electricians have a mate? :shades_smile:

I won't be doing any more on the electrics for a few weeks. Need to sort out some of the outside stuff (car port, etc.) while the ground is still manageable. If I leave it another month it will begin more than a tad hard to dig.