Electric Cable - Meter to home, sizes, material

[Formaleins]

Well after the recent storms my incoming supply and poles took a beating. The cable from the road to my home was snapped in 4 places so I need to replace it. The cable run is about 100m meter to consumer unit. I often suffer from low power despite being connected next to the transformer, generally it is ok about 225V but at certain times will drop to about 175V when running an 8KW water heater.

 

Obviously there are other times when locals are fiddling with welders and the like and it nose dives to 160V.

 

Looking at my original cable it is aluminium, 7 core, which I think is probably around 25mm SQ size, but the sheathing has no markings at all.

 

What is the largest diameter cable that is normally fitted to the homes here, locals tell me it is the 25mm stuff but I am sure that I have seen thicker, sometimes in a blue pvc sheath. I will probably stick with aluminium over copper just for the costs, but is there a size up from the 25mm or is that it?

 

We are on the 15/45 meter, single phase,  100m run for live and 100m for neutral. I know I need to keep the sizing reasonable as otherwise it wont fit into the connectors on the safety / consumer unit side.

 

Any ideas?

 

Cheers.

[bankruatsteve]

 

Simple.  Contact your PEA and do what they recommend.  Most likely 25mm² Al.

[Crossy]

OK 100m on a 15/45 would size out at 25mm² in copper, bump that to 35mm² if you go aluminium (cheaper).

 

If you already have voltage issues going 35mm² in copper or 50mm² in aluminium may be worthwhile.

 

The bigger sizes won't fit in the breakers or possibly the meter, but it's no issue to crimp on a pigtail of 25mm² at each end (do not trim strands to get it to fit).

 

How big do you want to go? Bangkok Cables do THW-A in up to 500mm².

[Formaleins]

6 hours ago, Crossy said:

OK 100m on a 15/45 would size out at 25mm² in copper, bump that to 35mm² if you go aluminium (cheaper).

 

If you already have voltage issues going 35mm² in copper or 50mm² in aluminium may be worthwhile.

 

The bigger sizes won't fit in the breakers or possibly the meter, but it's no issue to crimp on a pigtail of 25mm² at each end (do not trim strands to get it to fit).

 

How big do you want to go? Bangkok Cables do THW-A in up to 500mm².

Thanks again Crossy, USEFUL info as always! Understand the fit with breakers and yes, understand not to cut the damn strands like the locals do, crazy!  So, I could run two 25mm aluminium each for live and neutral? then crimp at the joints - I suspect a special tool might be in order any suggestions? The last thing I want is it all getting arsed up with a poor joint. Any suggestions for crimps for the aluminium @ 2 x 25mm?

 

Thanks as always! I might pass on the 500mm, my posts are a mix of poor concrete and termite ridden teak, would cost me more for the supports than the house is worth!

 

PS EDIT - would it be worthwhile putting the 2 x 25mm on the live and a single 25mm on the return? I just picked up 2 x 100m of 450/750 - 70C cable with the 7 core auminium, but this stuff looks a lot better than my original, the insulation is a lot thicker for one thing and it wasn't too expensive at 1240 B for each 100m length. problem with my cable at the minute is even worse than I thought, after climbing through 50 metres of broken teak trees and scrub, I have found that the sparks have put in two more joints, so my live feed is divided into 5 lengths joined with twists, covered with a bit of insulating tape and covered with some gaffa tape for good measure. Saying that, when the cables were broken in the storm my son and me rigged up some cable from my other 5/15 supply, about 50 or 60 metres on a two pin plug, using 1.5mm lighting cable (emergency only) and all the fridges were on, all the lights worked the two pcs and the routers all fired up, just wired the 2 cores into the main breaker and away it went. and as an added bonus the 8kw hot water for the shower fired up on about the 4kw setting so we could all get a shower, cable was probably glowing but needs are needs and surviving here with no electric for over 48 hours is no fun.

Edited April 30, 2019 by Formaleins

[sometimewoodworker]

16 minutes ago, Formaleins said:

Thanks again Crossy, USEFUL info as always! Understand the fit with breakers and yes, understand not to cut the damn strands like the locals do, crazy!  So, I could run two 25mm aluminium each for live and neutral? then crimp at the joints - I suspect a special tool might be in order any suggestions? The last thing I want is it all getting arsed up with a poor joint. Any suggestions for crimps for the aluminium @ 2 x 25mm?

 

Thanks as always!

 

PS EDIT - would it be worthwhile putting the 2 x 25mm on the live and a single 25mm on the return?

The current carried on the neutral is the same as on the line so no different sized conductors do not help.

 

you will probably have more difficulty with terminating 2 cables and fitting those into the meter and your house than a single cable.

[Fruit Trader]

13 minutes ago, sometimewoodworker said:

The current carried on the neutral is the same as on the line so no different sized conductors do not help.

The volts drop calculation would change if he increased the size of the live conductor.

[Formaleins]

34 minutes ago, sometimewoodworker said:

The current carried on the neutral is the same as on the line so no different sized conductors do not help.

 

you will probably have more difficulty with terminating 2 cables and fitting those into the meter and your house than a single cable.

makes sense I guess, but worth a try. Just hoped that using larger csa cable on the live might have helped a bit.

[Formaleins]

1 hour ago, sometimewoodworker said:

The current carried on the neutral is the same as on the line so no different sized conductors do not help.

 

you will probably have more difficulty with terminating 2 cables and fitting those into the meter and your house than a single cable.

Agreed, be nice to tag two 25mm together, but without the right gear it would end up as the usual Thai abortion, probably like what I have at the minute, cables twisted together with a pair of pliers, some insulating tape and more worry than it is worth. Without the proper tool to crimp cables together then I might just stick with the one 25mm. This what we ended up joining, slashing down with rai, ground is waterlogged and bare cables.....are they alive or are they dead?

Edited April 30, 2019 by Formaleins

[Formaleins]

snapped! by the wind! Dorothy never had this crap in Kansas!

Edited April 30, 2019 by Formaleins

[Formaleins]

Hi Crossy, you mentioned doubling up the cable and using a 25mm pig tail at either end, do you have any drawings / photos of the type of joint? At the house side it is a bit more straight forward, but for the meter side, I obviously would need to make a joint that will be acceptable to PEA, thanks.

[sometimewoodworker]

1 hour ago, Formaleins said:

Hi Crossy, you mentioned doubling up the cable and using a 25mm pig tail at either end, do you have any drawings / photos of the type of joint? At the house side it is a bit more straight forward, but for the meter side, I obviously would need to make a joint that will be acceptable to PEA, thanks.

He didn't talk about doubling up the cable, that was you, he talked about using a larger size of cable 36mm or 50mm and adding a short 25mm crimped pigtail at each end.

[TTL2]

14 hours ago, Formaleins said:

snapped! by the wind! Dorothy never had this crap in Kansas!

For the broken square wooden pole. I could suggest that you use a thick long PVC pipe to sleeved it in between (ensure it's longer in between the broken line in order to support the tension) and filled in the cement.

Alternatively you could heat up using burner to soften the PVC to grasp it onto the pole square shape and mould to shape it further cool it down using cold water to harden it back and you might need not to cement at all.  

[brianthainess]

19 hours ago, Formaleins said:

Thanks again Crossy, USEFUL info as always! Understand the fit with breakers and yes, understand not to cut the damn strands like the locals do, crazy!  So, I could run two 25mm aluminium each for live and neutral? then crimp at the joints - I suspect a special tool might be in order any suggestions? The last thing I want is it all getting arsed up with a poor joint. Any suggestions for crimps for the aluminium @ 2 x 25mm?

 

Thanks as always! I might pass on the 500mm, my posts are a mix of poor concrete and termite ridden teak, would cost me more for the supports than the house is worth!

 

PS EDIT - would it be worthwhile putting the 2 x 25mm on the live and a single 25mm on the return? I just picked up 2 x 100m of 450/750 - 70C cable with the 7 core auminium, but this stuff looks a lot better than my original, the insulation is a lot thicker for one thing and it wasn't too expensive at 1240 B for each 100m length. problem with my cable at the minute is even worse than I thought, after climbing through 50 metres of broken teak trees and scrub, I have found that the sparks have put in two more joints, so my live feed is divided into 5 lengths joined with twists, covered with a bit of insulating tape and covered with some gaffa tape for good measure. Saying that, when the cables were broken in the storm my son and me rigged up some cable from my other 5/15 supply, about 50 or 60 metres on a two pin plug, using 1.5mm lighting cable (emergency only) and all the fridges were on, all the lights worked the two pcs and the routers all fired up, just wired the 2 cores into the main breaker and away it went. and as an added bonus the 8kw hot water for the shower fired up on about the 4kw setting so we could all get a shower, cable was probably glowing but needs are needs and surviving here with no electric for over 48 hours is no fun.

All new house wiring its no longer allowed to be twisted together it must be clamped.

[bankruatsteve]

5 minutes ago, brianthainess said:

All new house wiring its no longer allowed to be twisted together it must be clamped.

Is this for Thailand?  What kind of "clamp".

[The Theory]

On 4/30/2019 at 12:41 PM, Formaleins said:

The cable from the road to my home was snapped in 4 places

Support the new one by “towing metal cable”. It won’t snap again it needs some work though at both ends. 

[KhaoYai]

What is your current power supply - 15 or 30 amps? A 15/45 meter does not determine your supply - its just the type of meter used for supplies between 15 and 45amps.

 

If you are suffering from low voltage and are on a 15amp supply as many are, it may be possible to upgrade it to 30amps.  My house was on 15amps but the PEA told me a higher power cable also passed my house. I therefore upgraded to a 30amp supply and no longer suffer from power drops - probably because very few of the other locals are on this cable.

 

I'm told that higher (45amp +) supplies are available but for some reason, in Thailand these are only available through a 3 phase system.

 

I'm mentioning this because you are about to replace your supply cable and may want to 'future proof' it.

 

16mm2 would be fine if you're on a 30amp supply - that's what was installed when mine was upgraded (previously 10mm2) and it's fine. However, I'm nowhere near 100m from the meter. If you want to go to 45amp you would need 25mm2.

 

There's a handy calculator here:

 

http://www.doncastercables.com/technical-help/

 

 

Edited May 1, 2019 by KhaoYai

[Formaleins]

6 hours ago, TTL2 said:

For the broken square wooden pole. I could suggest that you use a thick long PVC pipe to sleeved it in between (ensure it's longer in between the broken line in order to support the tension) and filled in the cement.

Alternatively you could heat up using burner to soften the PVC to grasp it onto the pole square shape and mould to shape it further cool it down using cold water to harden it back and you might need not to cement at all.  

That is a really smart idea, I will remember that! sadly due to the amount of fallen teak trees I will soon be having some rather natty teak wood electric poles, no more crappy concrete for me!

[Formaleins]

2 hours ago, KhaoYai said:

What is your current power supply - 15 or 30 amps? A 15/45 meter does not determine your supply - its just the type of meter used for supplies between 15 and 45amps.

 

If you are suffering from low voltage and are on a 15amp supply as many are, it may be possible to upgrade it to 30amps.  My house was on 15amps but the PEA told me a higher power cable also passed my house. I therefore upgraded to a 30amp supply and no longer suffer from power drops - probably because very few of the other locals are on this cable.

 

I'm told that higher (45amp +) supplies are available but for some reason, in Thailand these are only available through a 3 phase system.

 

I'm mentioning this because you are about to replace your supply cable and may want to 'future proof' it.

 

16mm2 would be fine if you're on a 30amp supply - that's what was installed when mine was upgraded (previously 10mm2) and it's fine. However, I'm nowhere near 100m from the meter. If you want to go to 45amp you would need 25mm2.

 

There's a handy calculator here:

 

http://www.doncastercables.com/technical-help/

 

 

Thanks for that, unfortunately where we are we are already on the highest available for this village, no signs of 3 phase either, jesus, it is only in the last few years that we were able to get a phone, there were no lines in our village only mobiles - even for internet you had to use a mobile for a modem.

[Formaleins]

7 hours ago, sometimewoodworker said:

He didn't talk about doubling up the cable, that was you, he talked about using a larger size of cable 36mm or 50mm and adding a short 25mm crimped pigtail at each end.

but the same principal applies, probably a longer pigtail, maybe a resin joint......if I could find one here!

[KhaoYai]

1 hour ago, Formaleins said:

Thanks for that, unfortunately where we are we are already on the highest available for this village, no signs of 3 phase either, jesus, it is only in the last few years that we were able to get a phone, there were no lines in our village only mobiles - even for internet you had to use a mobile for a modem.

When I bought my house I was told the same - 15amp maximum. That was almost 5 years ago but a couple of years ago I had occasion to talk with the engineers at my local PEA office.  He looked on a map and told me that there was a higher amperage cable going right past my house along with the others.  To cut a long story short, in 2017, my supply was upgraded to 30amp at a cost of 12,000 baht.

 

It might be worth your while to check with the engineers rather than ask at the admin office at your local PEA - I asked them on 2 different occasions and they told me no, the only way they would upgrade my supply was to either get 12 locals to sign up for an improved supply or pay 300,000. I don't know if that information was just wrong or whether, sometime between then and me talking to the engineers, someone else paid for the higher power cable - as I say, check with the engineers.

 

Although I, and I guess most people, don't need as much power in Thailand as I did in the UK, 15amps is woefully low.  I used to hear the microwave slow down when I turned the kettle on - not now.

[Formaleins]

20 minutes ago, KhaoYai said:

When I bought my house I was told the same - 15amp maximum. That was almost 5 years ago but a couple of years ago I had occasion to talk with the engineers at my local PEA office.  He looked on a map and told me that there was a higher amperage cable going right past my house along with the others.  To cut a long story short, in 2017, my supply was upgraded to 30amp at a cost of 12,000 baht.

 

It might be worth your while to check with the engineers rather than ask at the admin office at your local PEA - I asked them on 2 different occasions and they told me no, the only way they would upgrade my supply was to either get 12 locals to sign up for an improved supply or pay 300,000. I don't know if that information was just wrong or whether, sometime between then and me talking to the engineers, someone else paid for the higher power cable - as I say, check with the engineers.

 

Although I, and I guess most people, don't need as much power in Thailand as I did in the UK, 15amps is woefully low.  I used to hear the microwave slow down when I turned the kettle on - not now.

I never visit PEA, the cables and transformers are right outside our place, they are the only cables for miles around. (The microwave almost grinds to a stop here if you turn on the 8kw water heater...probably a blackout in the village too. We used to have to take power from a 200 metre run and we were about the last in line so often you could not even fire up a fluorescent light.) Now they put the new cable it is doable.

[sometimewoodworker]

1 hour ago, Formaleins said:

 

9 hours ago, sometimewoodworker said:

He didn't talk about doubling up the cable, that was you, he talked about using a larger size of cable 36mm or 50mm and adding a short 25mm crimped pigtail at each end.

but the same principal applies, probably a longer pigtail, maybe a resin joint......if I could find one here!

 

All of the normal joints are available if you go to a specialist shop.

 

You should really talk to someone who knows the details of reduction fittings and the various ways of doing it if you are going down the doubled line and neutral cables

[Formaleins]

6 minutes ago, sometimewoodworker said:

All of the normal joints are available if you go to a specialist shop.

 

You should really talk to someone who knows the details of reduction fittings and the various ways of doing it if you are going down the doubled line and neutral cables

Agreed, and to be honest, I am not going there, it is often enough hassle getting basics done properly, I have no sadistic self masochistic fetish in complicating matters here when it comes to electricity, they know what they know, they do what they do, they do not want some farang disturbing their mental equilibrium. I will settle for 25mm sq and live with it!

 

Cheers.

 

The original galactic warriors that installed my electrics seemed to think that 110-120V was pretty much ok, I had to take them by their nose rings to the meter on the road and show them that YES Thailand does have 230V, then drag them back and show them that after they wired everything up, we were now almost on an American supply of 120V! Took a while, some wires were moved around and eventually I no longer had a 120V voltage drop from the meter to the house, but what the hell ….TIT! (TIC is the same)

Edited May 1, 2019 by Formaleins

[sometimewoodworker]

4 hours ago, KhaoYai said:

I'm told that higher (45amp +) supplies are available but for some reason, in Thailand these are only available through a 3 phase system.

The supplies are

5/15

15/45

30/100

then 3 phase

15/45

and up

 

The maximum you can get is dependent on the local infrastructure so your area may not permit 30/100 but do have a 3 phase available.

[sometimewoodworker]

19 minutes ago, Formaleins said:

To cut a long story short, in 2017, my supply was upgraded to 30amp at a cost of 12,000 baht.

It was actually a 30/100A supply and about ⅔ of the price was for the different meter which you can get back if you move, the remaining ⅓  was for their work and paperwork 

[KhaoYai]

10 hours ago, sometimewoodworker said:

It was actually a 30/100A supply and about ⅔ of the price was for the different meter which you can get back if you move, the remaining ⅓  was for their work and paperwork 

Yes, I know I get something back - that was explained to me in their broken English and my poor Thai when I paid for the supply.  I also got 6000 back that the original owner paid when I produced a power of attorney from her on signing up for the upgrade.

 

30amp is the max available at the moment and it took a major new road being built (Bang Pa In - Korat motorway M6) for the higher power cable to be installed. The downside is that whilst construction of the new road is taking place, my house suffers numerous power cuts when they work on the supply - all other houses in the village unaffected because they are still on the 15amp cable ????.

 

What really gets to me is that you'd think my house is right out in the sticks - with the previous supply being only 15amp. Yes its rural but Makro is only 1km away and Tesco, Homepro and such just 2km. Still, its Thailand and they do things differently I guess.

 

Can you explain the 30/100amp category?  I was just told 30amp - maybe that's just what my local PEA office calls it. Does it mean 30amp minimum/100amp maximum?

Edited May 2, 2019 by KhaoYai

[KhaoYai]

10 hours ago, Formaleins said:

The microwave almost grinds to a stop here if you turn on the 8kw water heater...probably a blackout in the village too.

If you want constant hot water, fit an inverter air source heat pump - no I don't know what all that means but what I do know is that mine is only 1.2kw yet produces 200l of hot water @ 60 degrees C in about 1.5 hours from start up.

[Crossy]

32 minutes ago, KhaoYai said:

Does it mean 30amp minimum/100amp maximum?

 

It's 100A max. The 30A is the calibration current, no minimum load.

 

A 30/100 is the biggest single-phase supply you will get, next step will be 15/45 3-phase.

 

 

[sometimewoodworker]

14 minutes ago, KhaoYai said:

Can you explain the 30/100amp category?  I was just told 30amp - maybe that's just what my local PEA office calls it. Does it mean 30amp minimum/100amp m

There is no minimum, it is the range that it is granted to be accurate.

 

here is a 5/15 the smallest you can have

 

The meter can supply around 30~50% over it's range with no problems, though it may be inaccurate (which way do you think it will read)

 

Howeve just because you have a meter that is capable of reading a 130A load doesn't mean that the cables and transformer on the PEA side are capable of delivering it, or that your house side has big enough cables either.

 

For me at the moment each 20A load drops my supply voltage by 10V so with an unloaded supply of 215V a 130A load would  theoretically  drop my supply to 150V, it wouldn't in practice because I have under voltage protection that cuts in about 180V

[emptypockets]

Perhaps consider going underground. 20 odd years ago  I hired a bobcat with a trench digging attachment.  100 metres to the house. Conduit and 25sq mm copper conductors. Good for 70 amps at 5% voltage drop from memory.  Trench was a metre deep. 

I think going overhead will only cause you problems again, sooner or later, in the future. I also personally detest aluminium conductors especially if you need to joint them somewhere. 

Each to his own of course.