Does my CU set up comply with Thai regulation?

[bluejets]

It's a mistake to run (as in your case) 4 circuits from each of the rcd's.

Any one of which will trip the rcd and render 4 circuits inoperable.

Single combo's are available here, and I'd argue very little, if any, difference in cost with the added obvious advantage when tripped but also in board space.

[jim234]

9 hours ago, bluejets said:

It's a mistake to run (as in your case) 4 circuits from each of the rcd's.

Any one of which will trip the rcd and render 4 circuits inoperable.

Single combo's are available here, and I'd argue very little, if any, difference in cost with the added obvious advantage when tripped but also in board space.

I do understand the benefits of using RCBOs and have looked into it. As far as I have found a RCBO set up will cost me about 4x as much though. 

 

I will have about 30 circuits in total, so I am far from a black out in the event of a faillure where 4 circuits will be cut off. Also, I will divide my light circuits among several RCDs, so there will always be light close by.

 

So for me it basically comes down to the costs for choosing RCDs instead of RCBOs.

[jim234]

9 hours ago, Crossy said:

Yeah, just export your earth from CU1 to CU2, just one rod and one N-E bond.

 

I would feed the 10mm² to CU2 with a 50A breaker to give some discrimination but in the event of a short all bets are off as to which MCB will actually open first.

Ok a 50A breaker it will be!

[brianthainess]

I was not allowed to do my own electrics, it had to be a known registered electrician who had 4 unqualified laborers do most of the work. 

[MangoKorat]

On 9/27/2023 at 10:31 AM, Crossy said:

 

The customs chaps at the airport are on the lookout for easy pickings.

 

Over limit on booze or tobacco, there's no mechanism for paying duty so it's customs party time!

They get a manifest of everything bought at duty free during your trip before your flight arrives - all airports do.  Whether they have time/bother to check every report is another matter.

[bluejets]

On 9/29/2023 at 5:45 PM, jim234 said:

I do understand the benefits of using RCBOs and have looked into it. As far as I have found a RCBO set up will cost me about 4x as much though. 

Home state pricing or local suppliers here in Thailand?

It's still a mistake going 4 circuits to an elcb rather than single RCBO's regardless, for the reason I mentioned.

Wait until the day comes when you have to find a defect, and it will.

As I also mentioned, space is also a concern.

 

Might pay to mention that any work performed here by falang is under scrutiny so I'd make sure to have appropriate work permit.

Also be prepared to fork out if you decide to "bring stuff in" and get noticed, which could possibly be even after the fact.

In short, don't be a smart arse, they(authorities) don't like it one bit.

[surreybloke]

Just read this.    I was at a trade show in the uk recently  .    Speaking to the reps on the MK stand. Mk are owned by Honeywell. 

 

They are as I understand it about to market a single width RCBO  with double pole as a type A.     Made in China  BTW

 

Remember   Schneider manufacture type a rcbos in Thailand.    Can you buy them in the land of smiles. ????    5555

[bluejets]

Single width RCBO's have been around for donkey's ages......... I'd say at least 15 years.

[Crossy]

19 minutes ago, bluejets said:

Single pole RCBO's have been around for donkey's ages......... I'd say at least 15 years.

 

@bluejets did you mean single-width??

 

Single-width 2-pole (rather than solid neutral) RCBOs are certainly available, we use them in the BTS distribution boards, but they are not particularly common or cheap.

[MangoKorat]

Forgive my ignorance but I've noticed a lot of talk about 3 phase on this thread - never really looked at what 3 phase actually is.  When I upgraded to 30/100 the PEA told me if I wanted more, I'd have to go to 3 phase.  How would that work? Doesn't 3 phase run at around 400v?

 

The reason I'm asking is that I'm likely to be building a new house soon and I don't think the 30/100 supply I have is actually 30/100.  My microwave slows down when I flick the kettle on - I've checked the wiring on the ciruit and its 2.5 so it should carry the load.

[sometimewoodworker]

2 hours ago, MangoKorat said:

Forgive my ignorance but I've noticed a lot of talk about 3 phase on this thread - never really looked at what 3 phase actually is.  When I upgraded to 30/100 the PEA told me if I wanted more, I'd have to go to 3 phase.  How would that work? Doesn't 3 phase run at around 400v?

You should really do some reading so you know the questions to ask. No it’s not 400v unless you’re in the MEA it’s 380v or under.

Each phase is theoretically 220 V but often less.

 

2 hours ago, MangoKorat said:

The reason I'm asking is that I'm likely to be building a new house soon and I don't think the 30/100 supply I have is actually 30/100.  My microwave slows down when I flick the kettle on - I've checked the wiring on the ciruit and its 2.5 so it should carry the load.

 You really need a voltmeter on your supply, because it’s very likely that when you turn on the kettle you supply voltage drops (FWIW when I shower I get a 20V drop), this will be because the phase that you’re on has too many people on it. However, going to 3 phase doesn’t necessarily mean that you’re going to get a better supply. Probably one of the phases will be better but there’s no guarantee.

[bluejets]

23 hours ago, Crossy said:

 

@bluejets did you mean single-width??

 

Yes, before breakfast comment, seldom any good at that time. Cheers...........

[Crossy]

49 minutes ago, bluejets said:

Yes, before breakfast comment, seldom any good at that time. Cheers...........

 

Fixed it for you ???? 

[Crossy]

10 hours ago, MangoKorat said:

Forgive my ignorance but I've noticed a lot of talk about 3 phase on this thread - never really looked at what 3 phase actually is.  When I upgraded to 30/100 the PEA told me if I wanted more, I'd have to go to 3 phase.  How would that work? Doesn't 3 phase run at around 400v?

 

The reason I'm asking is that I'm likely to be building a new house soon and I don't think the 30/100 supply I have is actually 30/100.  My microwave slows down when I flick the kettle on - I've checked the wiring on the ciruit and its 2.5 so it should carry the load.

 

Thailand is 3-phase, 4-wire (3 phases + neutral). Single-phase supplies take from one phase and the neutral. So, if you have a 3-phase supply to your home you can treat it as if it was 3 single-phase supplies. 

 

The "400V" (actually 380V) is phase-to-phase and only relevant if you have 3-phase appliances.

 

It's very likely that your 30/100 isn't really capable of 100A, at least not whilst maintaining the 220V+-10% that it supposed to. Our 15/45 village supply drops about 25V at 50A so just about OK, but it doesn't take much load elsewhere in the village to pull it way down, the under-voltage trip opens at 165V which it does rather more often than I'd really like.

 

If you are building a new place, I would wire it as if you are having 3-phase then use a "single-phase kit" on the incomer if you start off with a single-phase supply (as your construction supply will be).

 

[MangoKorat]

15 hours ago, sometimewoodworker said:

You really need a voltmeter on your supply, because it’s very likely that when you turn on the kettle you supply voltage drops (FWIW when I shower I get a 20V drop), this will be because the phase that you’re on has too many people on it.

Yes, I have always suspected that I'm not receiving the supply I expected but I doubt anything will be done about it if I complain.  There are certain times of day when some appliances won't even operate, for example, I have 'touch control' bedside lamps which you tap to turn on or off + they have 3 brightness settings.  Recently I went to sleep leaving one light on at the dimest setting.  I woke up around 5am and tried to turn the lamp off, it wouldn't respond at all - neither get brighter nor turn off, I had to unplug it.  My bedroom ceiling fan often doesn't work between 5am and 6am - it just buzzes.  Two other ceiling fans that are a different brand will work at that time.  I suspect that what is happening is some major drawdown like a local factory turning on at the start of the day is creating demand on the supply somewhere further back down the line.  I thought these problems would stop when I upgraded that's why I did it but there's been no change.

 

When I build the new house its extremely likely that I will install a solar power system - I'm undecided if that will be on or off grid.  Off grid would require batteries - I would be going to solar mainly for environmental reasons but I am concerned about the damage that mining the metals required for batteries is causing.  It seems that humans have learned very little - in our quest to stop causing one type of damage to our planet, we are simply causing different damage in different regions.  However, another major reason is to be able to have aircon 24/7 without huge electricity bills so a lot of reading and thinking to do.

 

I'm also not too happy with the rules about solar installation if I'm understanding them correctly - an 'on grid' system must be installed by one of the PEA's approved suppliers???  To me that actually means - must be installed by one of the most expensive companies around but I'll check that out.  I intended on doing a lot of the work myself to save money. I would have expected that it would be acceptable for such an installation to simply be inspected and certified by a professional but it seems not if my understanding is correct.

[MangoKorat]

7 hours ago, Crossy said:

The "400V" (actually 380V) is phase-to-phase and only relevant if you have 3-phase appliances.

Confused - how many volts are each phase?  Sometimewoodworker states that in theory each phase is 220v so would that not = 660v?  Told you I was ignorant re electric ????,

Edited October 8, 2023 by MangoKorat

[Crossy]

5 minutes ago, MangoKorat said:

How many volts are each phase?

 

Phase to Neutral 220V your normal single-phase supply.

 

Phase to Phase 380V which is what 3-phase appliances see. 

 

The apparent "weirdness" is due to the 120^o phase angle between the phases, I'm not going to go into 3-phase theory here, but Mr Google or Wiki can be a lot of help in understanding.

[MangoKorat]

1 minute ago, Crossy said:

 

Phase to Neutral 220V your normal single-phase supply.

 

Phase to Phase 380V which is what 3-phase appliances see. 

So would I need some form of transformer to convert one of the phases to 220v to run the 'normal' household appliances?

 

I ask becase it is possible that I will be putting a car lift in and most of those are 3 phase.  Obviously that would not be possible if I go for an off grid solar system. The build is about a year away so better to get the thinking done now.

[Crossy]

21 minutes ago, MangoKorat said:

So would I need some form of transformer to convert one of the phases to 220v to run the 'normal' household appliances?

 

NO!

 

Because there is already 220V between any one of the phases and the neutral.

 

If you look at the poles outside your house you will see 4 wires, three of them are the phases and one (usually the top one) is the neutral. If you trace the wires that go to your house (via the meter) you will see that they are connected to one of the phases and the neutral.

 

No transformers or anything else needed, it's just the way 3-phase 4-wire works. Dead handy.

 

3-phase appliances just connect to the three phases without using the neutral, unless they have 220V control gear.

 

What sort of power consumption would the lift be? Plenty of 3-phase off grid inverters (either single unit or three single-phase units running together).

EDIT 2 A quick Google puts the lift motor at around 2HP, that's well within the capabilities of a single-phase installation, check with your chosen lift supplier to see if they offer a single-phase version.

 

EDIT This diagram may help, note that it's for 230V phase-neutral but you should get the idea.

 

 

[lom]

24 minutes ago, Crossy said:

EDIT This diagram may help, note that it's for 230V phase-neutral but you should get the idea.

Thailand has jacked up the transformer output voltage to 230V/400V where I live, I guess to follow which is becoming a global standard.

Europe has had it for decades.

 

[Crossy]

4 minutes ago, lom said:

Thailand has jacked up the transformer output voltage to 230V/400V where I live, I guess to follow which is becoming a global standard.

Europe has had it for decades.

 

 

Generally, PEA is 220V phase-neutral, MEA is 230V phase-neutral. Of course, locally all bets are off due to compensating for overloaded transformers and transmission lines.

 

In reality it matters little as all your kit should be happy with either voltage +- >10%.

 

[MangoKorat]

1 hour ago, Crossy said:

NO!

 

Because there is already 220V between any one of the phases and the neutral.

 

If you look at the poles outside your house you will see 4 wires, three of them are the phases and one (usually the top one) is the neutral. If you trace the wires that go to your house (via the meter) you will see that they are connected to one of the phases and the neutral.

???? mai khao jai - some of us just don't get certain things. For me its electricity at the input side of the consumer unit!!!  After that I'm fine - as long as I know that I have a live and a neutral running at 220-230v coming out of the consumer unit, I can work with that ????.

 

I spent 25 years of my working life repairing cars - including autoboxes and those babies can take some understanding but when it come to electricity - other than live, neutral and earth, I hit a brick wall.

 

In any case, I've already hijacked the OP's post enough already.

 

As I get nearer to planning my build, I intended asking questions on here, in particular regarding the solar power supply that I want.  I want to get this right - from the start, not end up with something that has limitations or doesn't give me what I want.  For example, at my current Thai house I installed an air source heat pump water heater (probably just gave away the name I used to go under on here). I did that for environmental reasons as I insist on having hot water available at all times.  Those things are incredible in terms of efficiency but in terms of electricity bills, the system doesn't work for me - because I didn't look into it enough in the first place.  I didn't realise that I was heating 200L of water and keeping it hot 24/7.  For someone who has a requirement for plenty of hot water all day, they would be a 'must have' but for someone who's just taking a couple of showers and washing dishes - a decent electric shower and under-sink water heater (or even just the kettle) would be a better choice. There may be other choices too.

 

I'm still a bit of a 'car nut' and like to do my own repairs - hence the lift installation.  As for the power required, I haven't gone into that yet, all I can say is it won't be a massive lift, not for 'hobby' use.  In the UK there are quite a lot of single phase lifts available these days - I presume because the efficiency and start-up properties of electric motors is much better than it used to be? I don't know what the situation in Thailand is but a quick scan reveals most that are advertised are 3 phase.

 

I remember years ago - I had a very old 3hp single phase motor running my compressor.  That thing used to blow suppy fuses all the time despite me increasing the wiring to 6mm. The fact was, I presume, that on start-up, it was just trying to draw down too much power.  I 'fixed' the issue by supplementing the fuse for a 7/16 bolt with the head cut off ????.  Looking back, that was pretty dangerous..........to say the least but it worked for over 10 years until I bought a new compressor with a 3hp motor that was half the size of the 'museum piece' and allowed the use of a fuse ????.

 

When I'm ready to do more in depth planning, I'll post on here but thanks for everyone's answers so far.

Edited October 8, 2023 by MangoKorat

[Crossy]

2 minutes ago, MangoKorat said:

I had a very old 3hp single phase motor running my compressor.  That thing used to blow suppy fuses all the time despite me increasing the wiring to 6mm. The fact was, I presume, that on start-up, it was just trying to draw down too much power.  I 'fixed' the issue by supplementing the fuse for a 7/16 bolt with the head cut off ????.

 

I do have this t-shirt although it was my employer who installed the bolt! I would have installed a proper 32A Commando socket on sensible wiring but, small company, no money, you know the story. 

[lom]

On 9/28/2023 at 8:25 AM, Crossy said:

And under/over voltage protection.

Very important, you can under certain occasions get very low phase voltage(s) that can destroy your water pump motor or fridge/aircon compressors. They are available for DIN-rail mounting in either 1-phase or 3-phase versions.

I'd recommend to use 3 of the 1-phase versions instead of the 3-phase version which will disconnect all 3 phases when there is a problem only on a single phase. The 1-phase versions will only disconnect the problematic phase.

[MangoKorat]

15 minutes ago, Crossy said:

 

 small company, no money, you know the story. 

I know it very well.

[sometimewoodworker]

6 hours ago, MangoKorat said:

, I have always suspected that I'm not receiving the supply I expected but I doubt anything will be done about it if I complain.  There are certain times of day when some appliances won't even operate,

That is wrong. If you get enough data you can get the PEA to actually do something. It is almost certain that you are seeing supply voltages at under 180V at times and that with enough data (at least a month and at several times a day) is enough, if you are lucky and politely ask or have influential friends, to get them to doing something.

[bluejets]

On 10/8/2023 at 6:20 PM, MangoKorat said:

air source heat pump water heater

Those things are rubbish, for several reasons.

They made them compulsory install here for a couple of years about 10 years ago, and were removed within 2 to 3 years at considerable cost I might add.

Been removed all over, replaced with the age old storage units.

Claims they make were at best, wildly over rated.

 

 

 

 

[MangoKorat]

15 minutes ago, bluejets said:

Those things are rubbish, for several reasons.

They made them compulsory install here for a couple of years about 10 years ago, and were removed within 2 to 3 years at considerable cost I might add.

Been removed all over, replaced with the age old storage units.

Claims they make were at best, wildly over rated.

 

 

 

 

As the owner of one, I can state quite clearly that you are wrong in geographical terms.  They are a highly efficient energy converter. The only problem I have with an air source heat pump such as the one I have, is that I made the wrong choice for my situation. To make a heat pump efficient in terms of heating water, you need to have a high demand for hot water - I don't.

 

I could take you to a restaurant just outside Pattaya that has had the exact same model of pump that I have for many years.  They use a lot more hot water than I do and the owner will clearly tell you that his bill for heating water has been cut by more than half.

 

I don't know which country you are referring to when you say they were installed compulsorily but if its a cold country, I can understand why you don't think highly of them.  Despite the claims of manufacturers they don't seem to work well at all in cold countries.  We are having all sorts of problems with them in the UK.

 

I can however tell you, that in a hot country such as Thailand, they work very well.

Edited October 9, 2023 by MangoKorat