Do Shower Heaters Include A Safety Cut Off

[Litlos]

Oh well I will throw my 2 Satang in here and try and answer a few questions.

The picture of the Thai wired distribution board by Mickba does not appear to be MEN as there is no hard wired link between the neatral and earth bars that I can see.

A few definitions and explanations might help. ELCB, RCDI, RCBO etc all perform the same basic function of earth leakage protection. A circuit breaker is like a mechanical fuse and can incorporate other functions as well. In a domestic situation it is very common for the earth leakage protection to be incorporated into the main circuit breaker (on the incomer) for a distribution board. On a single phase installation the main circuit breaker is generally 2 pole, this means the two wires from the meter both connect to the incoming side of the breaker which also helps give the unit the reference required to act as a RCBO etc. When the wires come in from the meter to the main circuit breaker they are both the same colour and are always checked for correct wiring so the active or phase goes to the distribution breakers and the neutral goes to the neutral link bar, WRONG - TIT so the active has a 50% chance of being wired to the wrong side of the Main breaker. As most Thai domestic wiring is not MEN no one really knows what is wired where.

So in the picture of the distribution board some greys are apparently active and some blacks are apparently active as well. As I type this I can hear a faint echo of Mai Pen Rai. Well this is sort correct as there is only a 50% chance the active is correct to the fuses why does it matter if the wiring is switched around as well, add into the mix the fact that most outlet scockets can have a plug inserted in either orientation and Mai Pen Rai may be the correct way of dealing with things.

However the does not matter theory falls apart when the power supply is hard wired to something like an oven/AC or shower unit which does have marked active and neutal points. The reason for this is generally in a piece of equipment the neutral is run straight through and the active is switched. For example in a basic oven the neutral goes straight to the heating element and the active goes through the on/off switch then the thermostat. So if the wiring is swapped the wrong parts of the circuit are live all the time.

mA = milli amps a measure of current flow. There is nothing wrong with having a main breaker having earth leakage and sub breakers also having earth leakage. Ideally they should have different mA ratings with the sub circuits having a smaller rating. An example of this is where the shower unit incorporates it own ELCB.

If the test button on a device ELCB does not trip its breaker then there are a few possibilities. One is there is no earth wire properly connected, the second is the the ELCB breaker is broken. A good idea to get this checked ASAP.

A lot of power socket outlets in Thailand (Asia?) do not have earth wiring included even if there is provision for the earth prong. A lack of a proper earth can make equipment with metal cases dangerous in case of incorrect wiring of active and neutral. There are also the tingles where the equipment incorporates a filter in a power supply that references earth. A good example of the is the desktop PC. No earth and the case can give a nasty tingle due to no return or drain path via the earth. Sometimes this can be cured by swapping the plug around in the socket to give possibly the correct orientation of active and neutral to the power supply. At the end of the day the best wiring is a proper earth and I believe that most (some?) new wiring in Thailand is being installed this way.

Cheers

[Kwasaki]

I don't think that's what Crossy was saying, but he can elaborate if so. Yes, the ELCB only protects the unit. I don't know why you are worried about the wires, but RCD at the CU is extra protection - which could be debated, I suppose.

Sorry, i haven't found Crossy's post yet, so i was just saying what I thought the OP meant in his post.

I'm not particularly worried about the cables from the shower 15 mA ELCB back to the CU, but I assume 30 mA protection on the whole house (possibly excluding fridge freezer and some lights if possible) would be a good idea?

I'll try again " mickba " as I said before I think you should wait until Crossy or electau come on or look at this http://www.crossy.co.uk/wiring/ it explains the Thailand 2 pole system or start another thread.

You only need to install one RCD positioned at the incoming supply to the house, you can have an isolator before that if you want.

The RCD is then connected the Dist box which has the row of MCB's.

From the given amp value of each MCB the live wire will supply the house circuits and household appliances.

Before things like shower units and heaters, air-con etc it's good to have what's called safety breaker switches which are same as MCB's.

Shower units have there own ELB or other protection, Oh !!! and usually ELB's trip switch test buttons on showers only work when power is going to the unit, no power no worky.

All water electrical appliances and metal cased products should be earthed back to the Dist box earth bar.

The main earth wire from the Dist box earth bar is then connected to the relative earth grounding system you have.

Edited October 31, 2011 by Kwasaki

[Crossy]

OK, let's take a simple and pragmatic approach to this.

Firstly, those built-in RCDs only protect you from an internal fault in the heater, they don't, for example, protect you if you touch the crappy taped joint on the incoming supply. That said, having one is far better than having nothing. Personally, I would have an RCD in the distribution board even if my chosen heater had an internal one.

There are several ways you can arrange things:-

1. A whole house RCD, cheapest option but there's the risk of being plunged into darkness when the breaker trips.
   
2. A split-service board, half the board has an RCD the other does not, or maybe each half has its own RCD (IEE 17th Edition) with the circuits distributed between the two, have a look here for a diagram http://www.crossy.co.uk/wiring/Consumer.html
   
3. Individual RCBOs for each circuit, an RCBO has both over current and earth leakage built in to one box. This is the most fault-tolerant arrangement as only one breaker will open in the event of an earth fault, but it's also by far the most expensive.
   

There is nothing inherently wrong with having an RCD protecting another RCD but even with a 30mA and 100mA rated unit it's difficult to define exactly which will trip, usually in the event of a solid L-E fault both will open anyway.

Personally, I would go for a split unit, with things like A/C and the freezer on the un-protected side or possibly give the freezer an RCBO.

[mickba]

Firstly, thanks for the replies.

I apologise to the OP if I've taken the thread beyond the scope he intended.

If the Mods would like me to start a new thread just tell me, but as Crossy has replied I'll persevere for now.

Shower heaters conforming to Thai Industrial Standards (TIS) are fitted with a 10mA RCD unit integral with the unit as an ON/OFF switch.

The heater should be earthed either to the existing earthing system or earthed to an individual electrode if the former is not possible.

The circuit to the heater should be protected by a 30mA RCD. The shower heater should be permanently connected in an approved manner.

Yes, it would be recommended that all final subcircuits be protected by one or more 30mA RCDs depending on the distribution of the circuits within the electrical installation.

The Panasonic shower was bought in Thailand 3 years ago and it definitely has a 15 mA RCD inside.

It is earthed back to the earthing system in the main CU.

My intention is that the circuit will also have a 30 mA RCD.

...................................

The picture of the Thai wired distribution board by Mickba does not appear to be MEN as there is no hard wired link between the neatral and earth bars that I can see.

A few definitions and explanations might help. .......................

..............................................

So in the picture of the distribution board some greys are apparently active and some blacks are apparently active as well. As I type this I can hear a faint echo of Mai Pen Rai. Well this is sort correct as there is only a 50% chance the active is correct to the fuses why does it matter if the wiring is switched around as well, add into the mix the fact that most outlet scockets can have a plug inserted in either orientation and Mai Pen Rai may be the correct way of dealing with things.

However the does not matter theory falls apart when the power supply is hard wired to something like an oven/AC or shower unit which does have marked active and neutal points. The reason for this is generally in a piece of equipment the neutral is run straight through and the active is switched. For example in a basic oven the neutral goes straight to the heating element and the active goes through the on/off switch then the thermostat. So if the wiring is swapped the wrong parts of the circuit are live all the time.

mA = milli amps a measure of current flow. There is nothing wrong with having a main breaker having earth leakage and sub breakers also having earth leakage. Ideally they should have different mA ratings with the sub circuits having a smaller rating. An example of this is where the shower unit incorporates it own ELCB.

If the test button on a device ELCB does not trip its breaker then there are a few possibilities. One is there is no earth wire properly connected, the second is the the ELCB breaker is broken. A good idea to get this checked ASAP.

A lot of power socket outlets in Thailand (Asia?) do not have earth wiring included even if there is provision for the earth prong. A lack of a proper earth can make equipment with metal cases dangerous in case of incorrect wiring of active and neutral. There are also the tingles where the equipment incorporates a filter in a power supply that references earth. A good example of the is the desktop PC. No earth and the case can give a nasty tingle due to no return or drain path via the earth. Sometimes this can be cured by swapping the plug around in the socket to give possibly the correct orientation of active and neutral to the power supply. At the end of the day the best wiring is a proper earth and I believe that most (some?) new wiring in Thailand is being installed this way.

Cheers

All much appreciated.

I do understand your explanations and I am concerned about the orientation of the wiring. I intend to spend the time to work out why some are connected wrongly step by step.

It isn't just the lives and neutrals which are mixed up, but there are several green cables connected to the neutral bar.

You are correct that there is no hard wire directly from earth to neutral bars and I plan to rectify that.... once I understand what those greens to neutral are.

I'm not happy that the supply to the Water Heater & Pump has been spliced into the 'ring main' (not ringed). I'd like them to have their own supply from the CU, or possibly share with one of the showers, but I have worked out how to do it yet.

The Pump is not earthed so I have to correct that too.

.....................................

I'll try again " mickba " as I said before I think you should wait until Crossy or electau come on or look at this http://www.crossy.co.uk/wiring/ it explains the Thailand 2 pole system or start another thread.

You only need to install one RCD positioned at the incoming supply to the house, you can have an isolator before that if you want.

The RCD is then connected the Dist box which has the row of MCB's.

From the given amp value of each MCB the live wire will supply the house circuits and household appliances.

Before things like shower units and heaters, air-con etc it's good to have what's called safety breaker switches which are same as MCB's.

Shower units have there own ELB or other protection, Oh !!! and usually ELB's trip switch test buttons on showers only work when power is going to the unit, no power no worky.

All water electrical appliances and metal cased products should be earthed back to the Dist box earth bar.

The main earth wire from the Dist box earth bar is then connected to the relative earth grounding system you have.

Thanks. Sorry, I did start to look at Crossy's posts, but digressed when I found the one about a blueprint for his new house.

I appreciate your clarification and mostly that's what I plan to do. The only thing I'm not sure about are the safety breakers before the A/C units, but I'll look at those too.

Regarding the second shower unit, with water flowing hot and the red power light on, the Test button does nothing, so I believe I need to investigate that one.

OK, let's take a simple and pragmatic approach to this.

Firstly, those built-in RCDs only protect you from an internal fault in the heater, they don't, for example, protect you if you touch the crappy taped joint on the incoming supply. That said, having one is far better than having nothing. Personally, I would have an RCD in the distribution board even if my chosen heater had an internal one.

There are several ways you can arrange things:-

1. A whole house RCD, cheapest option but there's the risk of being plunged into darkness when the breaker trips.
2. A split-service board, half the board has an RCD the other does not, or maybe each half has its own RCD (IEE 17th Edition) with the circuits distributed between the two, have a look here for a diagram http://www.crossy.co...g/Consumer.html
3. Individual RCBOs for each circuit, an RCBO has both over current and earth leakage built in to one box. This is the most fault-tolerant arrangement as only one breaker will open in the event of an earth fault, but it's also by far the most expensive.

There is nothing inherently wrong with having an RCD protecting another RCD but even with a 30mA and 100mA rated unit it's difficult to define exactly which will trip, usually in the event of a solid L-E fault both will open anyway.

Personally, I would go for a split unit, with things like A/C and the freezer on the un-protected side or possibly give the freezer an RCBO.

Hmmmm - That's thrown me a little, having been shopping today.

My intention was to buy a new split-service board (Option 2) but I couldn't find one on Safe-T-Cut's website or in 3 DIY stores or an electrical supplier.

Therefore, I purchased a stand alone Safe-T-Cut 50A Main Circuit Breaker with adjustable RCBO (Model PR20 50A) such as you describe as Option 1, which I intended to set at 30 mA.

I can't return it, but as it's adjustable down to 5 mA, I could utilise it next to the Water Heater & Pump, if you can tell me where I can find a split system.

I found lots of CUs with RCBO in place of the Main switch, but not a split one. I'm near Pattaya BTW.

Loss of power to the whole house is a pain I agree, but I do have one of those emergency lights fitted. Also, having explored the roof space, there are lots of cables up there which appear to be just twisted and taped (hopefully I'm wrong) and as they're draped across the steel joists I felt there was an argument for whole house RCD protection?

I hadn't appreciated that eg. 10 mA & 30 mA RCDs may both trip together in case of a fault

[Crossy]

No problem with this drifting slightly off topic, it's still all about safety

Since you have a Safe-T-Cut I would install it as intended in front of the main CU, your emergency light will as you say, prevent total darkness. Nothing wrong with doing it this way, millions of homes in the UK are wired like this (minus the emergency light) and we're not dropping like flies.

You are now safe whilst you find the elusive split board should you decide to continue

You're right, you are unlikely to be able to find a split board ready made, particularly in the major DIY stores (did you find 3 core flat cable there?). However, if you start with a regular board with a DIN rail mount for the components you can do anything you wish.

All you need to make a split unit from a regular CU is an extra Neutral bar and a DIN mount RCD to put in the middle.

If you can cut the existing neutral bar in half and still mount it safely that is one (very economical) solution (you may find that the existing bar is already split and a link installed).

Otherwise take a look at the Haco Thailand website http://www.hacothailand.com/ (Internet Explorer only), the last few pages of the Consumer Units section has all the bits you'll need to make up a split unit, have a look at TB-125 or possibly SB-T07 or SB-T05. Download the CU catalogue here http://www.hacothailand.com/fileupload/2018Mar09p9cyvn8.MCB%20no%20price.pdf the pictures are better.

I don't think Haco will deal direct with the public but a quick contact via their contact form (in Thai preferably) should net you a local dealer who can order what you need.

[electau]

Installing a 30mA RCD upstream of a 10mA RCD is perfectly allowable as the 10mA RCD will trip in less than 0.04seconds and the 30mA will trip in less than 0.2/0.3 seconds.

Max standing leakage current should nor exceed 30% of the rated unit. In practice this should be 1mA or less. Remember standing leakage current is additive.

If your electrical installation is TT or direct earthing RCDs must protect all final subcircuits, ie. permanently connected electrical equipment.

An RCBO is permitted to be used as a main switch. In the event of an earth fault it will disconnect the whole installation.

Circuit distribution can be (1) RCBO (main switch) MCBs (final subcircuits). or.(2) MCB (main switch) one or more RCDs or RCBOs,then MCBs ( final subcircuits) from the load side of the RCDs. Depending on the number of final subcircuits you may require more than one RCD.

DIN rail mounted MCBs and RCDs should be utilised if possible as they fit most load centre enclosures (distribution boards).

Edited October 31, 2011 by electau

[Litlos]

"You are correct that there is no hard wire directly from earth to neutral bars and I plan to rectify that.... once I understand what those greens to neutral are"

Mickba - Hold fire on the connection between the neutral and earth bars. Somewhere in TVF there is post from Crossy on MEN and TT systems. From memory the problem with installing the MEN link is if no one else has it you become the sole earth point for the neutral apart from at the transformer. I would like to be able to point you to the exact post, but very slow internet connection. Hopefully Crossy will come back and confirm or correct if I am wrong.

if you are going to be looking in the distribution board it is worthwhile confirming the active is the one going to the sub breakers as well. Apparently this is not always the case.

Cheers

[Crossy]

Yes Litlos, agree 100%

It is vital that you do NOT link N-E unless you KNOW that your area has MEN / PME implemented. Doing so could introduce a potentially hazardous situation. It won't kill you immediately but will lurk in the shadows waiting for a particular set of circumstances to occur before coming back to bite.

If in any doubt whatsoever do not install this link and leave the system as TT with overall RCD protection.

[electau]

It would be advisable not to use the MEN system unless it is used on the LV disribution system in your area. You should check with the PEA/MEA for their policy.

The TT system with RCDs is the safer option. That is NO link between the main neutral and the earthing system.

[mickba]

................................ Hold fire on the connection between the neutral and earth bars.

.............................................................

Yes Litlos, agree 100%

It is vital that you do NOT link N-E unless you KNOW that your area has MEN / PME implemented. Doing so could introduce a potentially hazardous situation. It won't kill you immediately but will lurk in the shadows waiting for a particular set of circumstances to occur before coming back to bite.

If in any doubt whatsoever do not install this link and leave the system as TT with overall RCD protection.

It would be advisable not to use the MEN system unless it is used on the LV disribution system in your area. You should check with the PEA/MEA for their policy.

The TT system with RCDs is the safer option. That is NO link between the main neutral and the earthing system.

Thanks for the advice and concern guys. Apart from my shopping yesterday, I'm treading very carefully on this and my priorities are to make the whole system as safe as possible (RCBO/s) and then to spend the time understanding how each circuit has been wired before changing anything.

It isn't a large house, but the previous occupier was massively into gadgetry in general,a full home cinema setup (sadly a little dated now) as well as an ornamental fish pond, so the resultant wiring is rather complex.

I live in a village of about 90 houses, with only about 4 Farang, so finding stuff out about the overall installation might be difficult.

I can appreciate that some BMs may be screaming "Call in a qualified Electrician" but I'm sure 'qualified' Electricians did this work in the first place and anyway, I want to understand how everything is wired.

I am a novice, as you'll no doubt have gathered. I have done 3 whole house rewires from scratch in UK, but the last one was almost 20 years ago (wow, where did that go?).

We did use PME earthing back then, but I was unaware of the risks if that is not the policy in my area, so thanks for that.

I always did this work in the past with 'hand holding' from afar and I shall certainly be careful to check everything I can before changing anything.

These days, the internet and forums like this make that hand 'holding' so much easier.

Your time spent is hugely appreciated and I hope others can benefit from your expertise and advice.

[Crossy]

I am a novice, as you'll no doubt have gathered. I have done 3 whole house rewires from scratch in UK, but the last one was almost 20 years ago (wow, where did that go?).

We did use PME earthing back then, but I was unaware of the risks if that is not the policy in my area, so thanks for that.

Three rewires from scratch even 20 years back hardly classes you as a novice, it's probably at least that long since I did any house bashing

Regulations and technology have moved on since then mind, that's why I appreciate the input of members like Electau (and previously elkangorito, sadly now left the forum) and several others who have up to date experience and knowledge.

BTW, why not draw out a TT system and add a single N-E link, then analyse what happens if you lose the neutral between you and the transformer.

Good luck with your rewire and take care

[mickba]

Three rewires from scratch even 20 years back hardly classes you as a novice, it's probably at least that long since I did any house bashing

Regulations and technology have moved on since then mind, that's why I appreciate the input of members like Electau (and previously elkangorito, sadly now left the forum) and several others who have up to date experience and knowledge.

BTW, why not draw out a TT system and add a single N-E link, then analyse what happens if you lose the neutral between you and the transformer.

Good luck with your rewire and take care

LOL - 3 rewires, very very slowly and methodically and the 'hand holding' was a key factor. Let's just say I'm very much not qualified.

"BTW, why not draw out a TT system and add a single N-E link, then analyse what happens if you lose the neutral between you and the transformer."

Yes, I thinik I've got your drift.

What I do need to find out, is what those 2 # 4mm Green cables connected to the neutral block are?

Although there's no visible hard link N-E, it may be possible that there is an indirect one?

Up in the roof, apart from the Greys & Blacks swapping around, Earth may be Green but more often it's White.

In answer to your previous Q BTW - No, I haven't found flat Twin & Earth here - I've bought separate 4mm Green for Earth so far.

Thanks.

[Kwasaki]

Oh !!! and usually ELB's trip switch test buttons on showers only work when power is going to the unit, no power no worky.

The only thing I'm not sure about are the safety breakers before the A/C units, but I'll look at those too.

Regarding the second shower unit, with water flowing hot and the red power light on, the Test button does nothing, so I believe I need to investigate that one.

Also, having explored the roof space, there are lots of cables up there which appear to be just twisted and taped (hopefully I'm wrong) and as they're draped across the steel joists I felt there was an argument for whole house RCD protection?

I'm just another DIY Thailand electrician not by choice I guess, just ended up having to check up on my survival rating.

The safety breakers switches in the room for A/C units are just like an on & off switch but also act as a MCB.

The shower ELB test button not working yeah !! you need to look at that it may need replacing or like one of mine the push button was not correctly positioned for testing.

Regarding twisted cables taped in loft ( hopefully your wrong ) Noooooo !!! you are most probably right.

Me's I got some of these :- And some of these, in-case the tape failed :-

Edited November 1, 2011 by Kwasaki

[thaibeachlovers]

................................ Hold fire on the connection between the neutral and earth bars.

.............................................................

Yes Litlos, agree 100%

It is vital that you do NOT link N-E unless you KNOW that your area has MEN / PME implemented. Doing so could introduce a potentially hazardous situation. It won't kill you immediately but will lurk in the shadows waiting for a particular set of circumstances to occur before coming back to bite.

If in any doubt whatsoever do not install this link and leave the system as TT with overall RCD protection.

It would be advisable not to use the MEN system unless it is used on the LV disribution system in your area. You should check with the PEA/MEA for their policy.

The TT system with RCDs is the safer option. That is NO link between the main neutral and the earthing system.

Thanks for the advice and concern guys. Apart from my shopping yesterday, I'm treading very carefully on this and my priorities are to make the whole system as safe as possible (RCBO/s) and then to spend the time understanding how each circuit has been wired before changing anything.

It isn't a large house, but the previous occupier was massively into gadgetry in general,a full home cinema setup (sadly a little dated now) as well as an ornamental fish pond, so the resultant wiring is rather complex.

I live in a village of about 90 houses, with only about 4 Farang, so finding stuff out about the overall installation might be difficult.

I can appreciate that some BMs may be screaming "Call in a qualified Electrician" but I'm sure 'qualified' Electricians did this work in the first place and anyway, I want to understand how everything is wired.

I am a novice, as you'll no doubt have gathered. I have done 3 whole house rewires from scratch in UK, but the last one was almost 20 years ago (wow, where did that go?).

We did use PME earthing back then, but I was unaware of the risks if that is not the policy in my area, so thanks for that.

I always did this work in the past with 'hand holding' from afar and I shall certainly be careful to check everything I can before changing anything.

These days, the internet and forums like this make that hand 'holding' so much easier.

Your time spent is hugely appreciated and I hope others can benefit from your expertise and advice.

You're welcome to expand the post. It's all interesting, thanks everyone, I'm learning a lot.

When I had the shower put in, I only employed an electrician because it's the sister in law's house, and wanted immunity if it all goes wrong. However, he was as bad as I expected, and I had to sort a few things out after he'd gone. I'm sure he's used twisted wires in the roof too, but I don't have a long enough ladder to get up there and check it out.

[mickba]

..................................I'm just another DIY Thailand electrician not by choice I guess, just ended up having to check up on my survival rating.

The safety breakers switches in the room for A/C units are just like an on & off switch but also act as a MCB.

The shower ELB test button not working yeah !! you need to look at that it may need replacing or like one of mine the push button was not correctly positioned for testing.

Regarding twisted cables taped in loft ( hopefully your wrong ) Noooooo !!! you are most probably right.

Me's I got some of these :- And some of these, in-case the tape failed :-

I think electrical work in Thailand is one area where ignorance is not bliss and, even if we don't do the work ourselves, it pays to try to understand how our homes have been wired.

I understand the safety breakers for the A/C, but the supply comes from the roof through conduit directly into the units, so I have to look sometime how easy it would be to intercept the supply and route it through a breaker. I think that can be later.

I fitted an RCBO breaker to the Water Heater & Pump supply today and earthed the Pump. I'm not done there as I would like to take the supply from the cables I laid for the Panasonic Shower, but I haven't figured how to get across the suspended ceilings to that wal yetl. Also, it's darned hot up there.

I'll investigate the other shower tomorrow and start labelling cables to get ready to fit the RCBO to the main CU as I'll have to disconnect everything to re-route the main supply cables.

I hope I'm wrong about the twisted cables, but I'm not looking too hard until I have whole house RCBO protection. If they are twisted I reckon I'd need up to 50 of those boxes and a whole lot of those jointing thingies.

One more complication is that I'd been assuming that the Kitchen CU was supplied from the main CU, but with the latter turned off today, the Kitchen CU was still live.

I'd had a quick look at the main incoming cables and I didn't see where they'd been intercepted, so I need to go back to check where it gets supply from, as that means I still won't have whole house protection with an RCBO on the main CU.

The suspended ceilings make all of this pretty difficult up there.

You're welcome to expand the post. It's all interesting, thanks everyone, I'm learning a lot.

When I had the shower put in, I only employed an electrician because it's the sister in law's house, and wanted immunity if it all goes wrong. However, he was as bad as I expected, and I had to sort a few things out after he'd gone. I'm sure he's used twisted wires in the roof too, but I don't have a long enough ladder to get up there and check it out.

Thanks, I'll try not to stray too far - I'll be back to Shower Earth Trips tomorrow.

As you say, it's all interesting stuff, if only to show people how dodgy some of this work can be.

I know what you mean about the ladder, I had to go and buy a 9 footer to get me up to the hatch.

I'll post some more pics later.

[mickba]

........................................

I'm just another DIY Thailand electrician not by choice I guess, just ended up having to check up on my survival rating.

The safety breakers switches in the room for A/C units are just like an on & off switch but also act as a MCB.

The shower ELB test button not working yeah !! you need to look at that it may need replacing or like one of mine the push button was not correctly positioned for testing.

Regarding twisted cables taped in loft ( hopefully your wrong ) Noooooo !!! you are most probably right.

Me's I got some of these :- And some of these, in-case the tape failed :-

Just to give you, or anyone who hasn't looked up there an idea of what I'm looking at, I took a few pics.

Bear in mind that this village was built by a main contractor and probably wired by a 'qualified' sub contracting Thai electrician.

The one owner before me added many things, but he's not a DIYer and would have intended to use qualified electricians.

A general view of the spaghetti up there :-

..

I checked how come the kitchen supply isn't off when the main CU is off - it's been spliced into the incoming supply lines and taped.

Worse than that, it seems that perhaps the incoming supply cables were too short...... so they added a bit more on.

I haven't investigated too closely, but those joints do seem to be just twisted and taped - when I disturbed one of them I got a whole lot of sparks when it touched one of the metal ceiling fixings.

So much for my idea that by putting an RCBO on the main CU I'd have whole house protection.

I'm not of a nervous disposition, but that is scary. I guess I have to give in and get someone in to make some proper joints on the incomers.

Just one more thing I've found. Investigating a leak from the jacuuzzi I found that it has its own 30 mA RCBO, which is OK, but having to dismantle the bath to find it isn't so good. It looks like the supply has again been taken from the 16A ring main (not ringed) - more spurs here that Roy Rogers.

[mickba]

......................................................

An RCBO is permitted to be used as a main switch. In the event of an earth fault it will disconnect the whole installation.

Circuit distribution can be (1) RCBO (main switch) MCBs (final subcircuits). or.(2) MCB (main switch) one or more RCDs or RCBOs,then MCBs ( final subcircuits) from the load side of the RCDs. Depending on the number of final subcircuits you may require more than one RCD.

............................................................

Regarding my post above, in order to rectify the unsafe jointing which has been done to the main incoming cables, could you advise on what part to use eg. a junction box or a breaker switch or what?

Thanks.

[Kwasaki]

Regarding twisted cables taped in loft ( hopefully your wrong ) Noooooo !!! you are most probably right.

Me's I got some of these :- And some of these, in-case the tape failed :-

A general view of the spaghetti up there :-

I checked how come the kitchen supply isn't off when the main CU is off - it's been spliced into the incoming supply lines and taped.

Worse than that, it seems that perhaps the incoming supply cables were too short...... so they added a bit more on.

So much for my idea that by putting an RCBO on the main CU I'd have whole house protection.

Just one more thing I've found. Investigating a leak from the jacuuzzi I found that it has its own 30 mA RCBO, which is OK,

It looks like the supply has again been taken from the 16A ring main (not ringed) - more spurs here that Roy Rogers.

Best to wait for the qualified sparkys Crossey & electau to reply on this.

Your view of the loft looks pretty normal for here to me.

Firstly :- As for the kitchen, if your electrical incoming supply cable has been compromised, that needs to be reinstated with a connecting junction box if there is no isolator switch before the spliced cable joint.

Secondly :- If the splice is a good joint maybe put a separate RCB on the cable to the Kitchen feed.

Thirdly :- Where a bit more cable is added if you cannot replace the cable easily then re-connect joints with a junction box.

Forth :- Jacuzzi, I would think it is most common the wiring in Thailand being spur or what is called " radial circuit " if it has a functioning RCB I would say it's OK.

I would still go ahead with installing an RCB before your dist box.

[mickba]

Best to wait for the qualified sparkys Crossey & electau to reply on this.

Your view of the loft looks pretty normal for here to me.

Firstly :- As for the kitchen, if your electrical incoming supply cable has been compromised, that needs to be reinstated with a connecting junction box if there is no isolator switch before the spliced cable joint.

Secondly :- If the splice is a good joint maybe put a separate RCB on the cable to the Kitchen feed.

Thirdly :- Where a bit more cable is added if you cannot replace the cable easily then re-connect joints with a junction box.

Forth :- Jacuzzi, I would think it is most common the wiring in Thailand being spur or what is called " radial circuit " if it has a functioning RCB I would say it's OK.

I would still go ahead with installing an RCB before your dist box.

Following your numbering above :-

Firstly & Secondly - Where the 2.5 mm supply for the kitchen has been taken from the main incomers (no isolator switch before) it appears that the main cables have not been cut, so my layman's thought is to remove the kitchen supply cables (cut them) and make good the sections of the main cables which have been bared as best I can and enclose them in a box perhaps, but not a junction box )?

I'm thinking that I would then take the 2.5 mm kitchen supply cable down to the RCBO I'm fitting at the Main CU and take the supply from there, perhaps via it's own MCB for isolation purposes. Then the cable and the kitchen would be protected and could be isolated.

Thirdly - I agree that a junction box would be correct, but I wondered about putting a high amperage (100?) switch up there instead so that I could then do the installation of the RCBO at the Main CU with the incoming power off.

Fourthly - I'm not greatly concerned about the jacuzzi, but later I might move the CU outside the bath. It just seems a bit daft to have to unscrew and remove the bath panel to switch off the supply or reset the trip.

Thanks for your thoughts.

[electau]

Circuits should be wired in a loop in loop out method, That is the circuit from the MCB at the switch board to either the switch or the light fitting in the case of lighting circuits and for power circuits from socket outlet to socket outlet.

Junction or cable termination boxes need only to be used where required. Eg additions or alterations to circuit wiring.

The so called ring circuit should not be used.

Flat 2 core and earth TPS cable should be used. This will give you an earth at all points of utilisation. Cable can be run as unenclosed in free air in ceiling spaces and cavity walls and on the surface of walls enclosed in PVC duct.

Terminals from junction boxes can be screw type tunnel,( BP/Clipsal) or insulation displacement type (Waco) or the US screw on wire lock type (3M).

Twisted and taped joints must never be used.

All final subcircuits must have an overcurrent protective device.(MCB or RCBO) the size in amps must not exceed the current rating of the cable. The maximum demand of the circuit must not exceed the rating of the cable.