Domestic Electrical Wiring

[jimmi]

Cros,

I looked closely at your split service connection. I see what you tring to do with this. I think I like about 50% of it. If I get trips with the whole system/correct wiring diagram, I want to know why, I'm getting the trips, so I can repair/replace the circuit/item that is causing the trip. If I have an item that is "electrically Leaky" I want to know so that item can be replaced.

Of Coarse, my first and foremost concern is safety. From only a SAFETY point of view, is there a reason why the split service connection is better than the whole system/correct wiring diagram?

I looked at the construction of the square D box. I think the split connection system might be hard to do due to the design of the box (the location of the neutral bar/bus). I downloaded a copy of the diagram for the split connection and will talk to my electrician about it and see what he thinks. I of coarse would rather hear form you or lop3 or elkangorito about this. Just so you know, I am more concerned with safety then money. What do you think guys?

Thanks,

Jimmi

Edited May 10, 2006 by jimmi

[elkangorito]

Cros,

I looked closely at your split service connection. I see what you tring to do with this. I think I like about 50% of it. If I get trips with the whole system/correct wiring diagram, I want to know why, I'm getting the trips, so I can repair/replace the circuit/item that is causing the trip. If I have an item that is "electrically Leaky" I want to know so that item can be replaced.

Of Coarse, my first and foremost concern is safety. From only a SAFETY point of view, is there a reason why the split service connection is better than the whole system/correct wiring diagram?

I looked at the construction of the square D box. I think the split connection system might be hard to do due to the design of the box (the location of the neutral bar/bus). I downloaded a copy of the diagram for the split connection and will talk to my electrician about it and see what he thinks. I of coarse would rather hear form you or lop3 or elkangorito about this. Just so you know, I am more concerned with safety then money. What do you think guys?

Thanks,

Jimmi

Jimmi,

I agree with Crossy. You can use a 'split' consumer board. BUT please ensure that all metal connections that have been 'cut', have at least a 13mm air gap between them, without any sharp edges (file them until they are smooth).

I was going to add this later but your questions have brought this to the fore now. A good minimum size for a distribution board (consumer unit) is at least a 12 pole board...the bigger, the better. This allows more room for MEN connections as well as more room for general cabling. I have seen many 'consumer units' that have been crammed with cables & absolutely no space for anything. Also, these crammed units usually have many 'suspect' connections due to the lack of space. Personally, I would have a minimum 18 pole consumer unit.

A bigger 'consumer unit' will also allow for any future expansion.

Also, if you do not wish to do any splitting of the consumer unit's Active busbar (the Neutral bar should not be split at all), you can always have individual ELCB's for the required circuits. This costs more dollars but is a little more easier to deal with.

[Crossy]

Of Coarse, my first and foremost concern is safety. From only a SAFETY point of view, is there a reason why the split service connection is better than the whole system/correct wiring diagram?

I looked at the construction of the square D box.

Jimmi.

You can replace the incoming breaker with a 100mA ELCB, everything will be protected then.

The main reason for splitting off inherently leaky devices is to prevent "nuisence trips", you don't want your freezer to be killed by an accidental trip whilst you are away for two weeks, pooh

From a purely SAFETY standpoint there is little difference between split / non-split

Edited May 10, 2006 by Crossy

[lopburi3]

I would go with what you have and the electrician understands. If you need to remove items from the protection later you can buy another panel for that (I have four panels in my house). I have no problem with having lights on protected circuit in your own home as we all have plenty of experience in navigating house in the dark during power failures; or sneaking out for the Dagwood sandwich. For public or commercial buildings it would be a serious issue. Once you have the grounded outlets make sure you attach a ground wire (assuming your appliances do not already have) and a three pin plug. I have used the sold with two conductor cord and replaced plug and taped ground wire to it (from ground lug on unit) on a water cooler and several small refrigerators - a more glamorous fix would be to replace the electric cord but when done could not find multi strand 3 wire (and would also be more work).

[elkangorito]

Of Coarse, my first and foremost concern is safety. From only a SAFETY point of view, is there a reason why the split service connection is better than the whole system/correct wiring diagram?

I looked at the construction of the square D box.

Jimmi.

You can replace the incoming breaker with a 100mA ELCB, everything will be protected then.

The main reason for splitting off inherently leaky devices is to prevent "nuisence trips", you don't want your freezer to be killed by an accidental trip whilst you are away for two weeks, pooh

From a purely SAFETY standpoint there is little difference between split / non-split

Crossy,

I believe the idea of using a 100mA RCD as a Main Switch, is for cost savings as well as to avoid nuisance tripping (as indicated by your PM). This is all well & good but I do think it worthwhile to point out that this Main RCD will not cover 'personal protection', which stops at a current of no greater than 30 mA.

I still think it is better to have individual ELCB's for each circuit. Because of the way the world is going (appliances are now very cheap to buy), it is really no longer a problem to worry about refrigerators being connected to an earth leakage circuit. As you know, the residual earth leakage problem, only arrises when using old appliances, which probably should be replaced anyway. I guess if one wants to keep their fridge for a long time because it still does it's job, it may begin to trip ELCB's as it gets older. As long as it is properly earthed with an MEN system in place, it should not present a real safety problem.

I think it needs to be strongly stressed, so that people don't get the wrong idea, the use of a 100mA Main ELCB is for discrimination purposes only. That is, the ultimate requirement is that if such a device is used, the installation MUST have 30 mA ELCB's downstream. I have no problem with this if applied as such. But I still prefer each circuit to be protected individually by 30mA 20mS ELCB's.

[elkangorito]

I would go with what you have and the electrician understands. If you need to remove items from the protection later you can buy another panel for that (I have four panels in my house). I have no problem with having lights on protected circuit in your own home as we all have plenty of experience in navigating house in the dark during power failures; or sneaking out for the Dagwood sandwich. For public or commercial buildings it would be a serious issue. Once you have the grounded outlets make sure you attach a ground wire (assuming your appliances do not already have) and a three pin plug. I have used the sold with two conductor cord and replaced plug and taped ground wire to it (from ground lug on unit) on a water cooler and several small refrigerators - a more glamorous fix would be to replace the electric cord but when done could not find multi strand 3 wire (and would also be more work).

Lop,

I'm not having a 'go' at you but let me know how you fair when your house is on fire & the lights have tripped on earth leakage. I'm sure that 'panic' mode will make a big difference when trying to find one's way out of a dark & burning house...especially when leading other panicing people.

Also, I hope that all of your 4 distribution boards are fed from the 1 Main Distribution Board. In Thailand, I have seen many an installation whereby each distribution board is fed from the incoming supply. VERY DANGEROUS. It does not allow for a proper MEN connection to be of any use as well as, it is dangerous for isolation purposes. ie 'switching off' a main switch, 'switches off' what? At least, with 1 main switch & correctly labelled sub-circuits, one is easily able to safely isolate a circuit that then may be worked upon. Unless one has an intimate knowledge of the wiring of the installation, circuits cannot be safely isolated. Who wants to trace circuits through ceilings or floors to make sure that something is isolated? I realise that only qualified people should be working on electrics but TIT. I think Thai electricians do this because they know little or nothing about cascading or discrimination between protective devices.

Labelling of electrical equipment is another important Australian Standard (I dare say an important British Standard as well). Is this done in Thailand? Not that I have seen.

[lopburi3]

Having RCB protection for all circuits is likely to prevent electrical fires and I do not believe the likelihood of such fires to be very great in cement building construction as found here.

As for my panels they feed from the main distribution panel and all grounds lead back to that panel/ground.

I believe the Safe-T-Cut he has will have a max trip of 25 or 30ma so it is good for life protection if not turned off.

[elkangorito]

I believe the Safe-T-Cut he has will have a max trip of 25 or 30ma so it is good for life protection if not turned off.

Let's just hope he has.

[jimmi]

Hi guys,

An update from my house. The work is done. Two electricians and myself completed the work in two days. All wires/cables were replaced. My house is now properly grounded. I replaced both hot water heaters with new Toshiba units with their own (built in) ELCB and on their own circuit. I am very pleased with the work the electricians did. There were a couple things they started to do that I had them do different. For example, When they tied two or more wires together they would simplely twist the two wires together and tape it. I stoped that and made them use wire nuts and then tape the wire nut to the wire. When the breaker box was finally wired I watched very close. They did NOT install the MEN link. I again showed them the drawing from this thread and the instructions from the Safe-T-Cut. The Safe-T-Cut instructions piont out the MEN link. The MEN link was then installed. The Safe-T-Cut has 5 settings to it. They are Direct (protection turned off), 30mA, 20mA, 10mA, and 5mA. I have it set to 5mA. Everything is now properly earthed including my computer, washing machines, and water pump.

Thanks guys for all your help as. My house was a death trap waiting to happen. Not anymore.

Jimmi

[Crossy]

Hi guys,

An update from my house. The work is done. Two electricians and myself completed the work in two days. All wires/cables were replaced. My house is now properly grounded. I replaced both hot water heaters with new Toshiba units with their own (built in) ELCB and on their own circuit. I am very pleased with the work the electricians did. There were a couple things they started to do that I had them do different. For example, When they tied two or more wires together they would simplely twist the two wires together and tape it. I stoped that and made them use wire nuts and then tape the wire nut to the wire. When the breaker box was finally wired I watched very close. They did NOT install the MEN link. I again showed them the drawing from this thread and the instructions from the Safe-T-Cut. The Safe-T-Cut instructions piont out the MEN link. The MEN link was then installed. The Safe-T-Cut has 5 settings to it. They are Direct (protection turned off), 30mA, 20mA, 10mA, and 5mA. I have it set to 5mA. Everything is now properly earthed including my computer, washing machines, and water pump.

Thanks guys for all your help as. My house was a death trap waiting to happen. Not anymore.

Jimmi

Well done that man :)

As you noticed, it is VITAL to WATCH your contractor at all stages of installation.

Setting your unit to anything less than 30mA will provide life protection from direct contact.

It's the 'Bypass' function of the Safe-T-Cut that we don't like, so long as you understand the implications of selecting this mode (as you appear to) then there is no problem.

[elkangorito]

Hi guys,

An update from my house. The work is done. Two electricians and myself completed the work in two days. All wires/cables were replaced. My house is now properly grounded. I replaced both hot water heaters with new Toshiba units with their own (built in) ELCB and on their own circuit. I am very pleased with the work the electricians did. There were a couple things they started to do that I had them do different. For example, When they tied two or more wires together they would simplely twist the two wires together and tape it. I stoped that and made them use wire nuts and then tape the wire nut to the wire. When the breaker box was finally wired I watched very close. They did NOT install the MEN link. I again showed them the drawing from this thread and the instructions from the Safe-T-Cut. The Safe-T-Cut instructions piont out the MEN link. The MEN link was then installed. The Safe-T-Cut has 5 settings to it. They are Direct (protection turned off), 30mA, 20mA, 10mA, and 5mA. I have it set to 5mA. Everything is now properly earthed including my computer, washing machines, and water pump.

Thanks guys for all your help as. My house was a death trap waiting to happen. Not anymore.

Jimmi

Good on ya Jimmi ...way ta go!!

I'm with Crossy...you've got to watch these bloody Thai electricians. I noticed something highly dangerous in my friends place at Klaeng...the place that I wired. The electrician had twisted the incoming mains cables to the consumer cables. No clamps or proper connections existed, just twisting. The supply cable was 35 mm squared multicore Aluminium & the consumer mains was 10 mm squared multicore copper. I immediately re-connected these sets of cables together with Line Clamps (brass) & wrapped them in electrical tape (unheard of in Thailand). When I purchased the clamps, the Thai electrical wholesaler gave me a funny look

Thai electricians are notorious for connecting cables by twisting them together. This is highly dangerous & very bad practice. In Australia, things called 'BP connectors' are used to connect cables together. I don't know for what 'BP' stands. All electrical connections must be properly connected (not just twisted). It is TOTALLY unacceptable to break an earth cable OR to use a connector to connect earth cables together. Check your installation to see that this has not happened.

Nonetheless, good job mate . Just make sure that all your metal-clad appliances are properly earthed to the 3 pin socket (power point).

Well done.

[Crossy]

It is TOTALLY unacceptable to break an earth cable OR to use a connector to connect earth cables together.

Good point old chap. I'll ensure that this important safety principle is clear on the web page.

BTW. Do you have a recommended method for ensuring ground continuity through a series of daisy-chained outlets. In the UK we have ring mains so (in theory at least) it is highly unlikely that a single open circuit ground will result in a dangerous loss of appliance grounding.

[elkangorito]

It is TOTALLY unacceptable to break an earth cable OR to use a connector to connect earth cables together.

Good point old chap. I'll ensure that this important safety principle is clear on the web page.

BTW. Do you have a recommended method for ensuring ground continuity through a series of daisy-chained outlets. In the UK we have ring mains so (in theory at least) it is highly unlikely that a single open circuit ground will result in a dangerous loss of appliance grounding.

According to Australian Standards, 3 pin power outlets that are wired with 2c + E cable, are wired in parallel. This means that the earth cable is broken at each power outlet to facilitate the connection. The bared ends of each cable MUST be twisted together & then screwed to the outlet. This is considered acceptable whereas breaking the earth cable for any other reason, is not acceptable.

Please see the attached PDF for info about testing an installation. It is not intended only for domestic. I didn't want to add this info now but it appears relevant.

It covers many essential "commisioning" tests required for domestic installations.

[Crossy]

According to Australian Standards, 3 pin power outlets that are wired with 2c + E cable, are wired in parallel. This means that the earth cable is broken at each power outlet to facilitate the connection. The bared ends of each cable MUST be twisted together & then screwed to the outlet.

Cheers, this is pretty much what we do in the UK. I was taught to run the cable in one piece all around the ring leaving a loop of about 6" at each outlet location. It is then possible with UK standard twin + earth to loop out the bare earth conductor without cutting it (you still have to cut and twist the live and neutral). Not easy to do with the fully insulated cable that is the norm in Thailand.

[elkangorito]

According to Australian Standards, 3 pin power outlets that are wired with 2c + E cable, are wired in parallel. This means that the earth cable is broken at each power outlet to facilitate the connection. The bared ends of each cable MUST be twisted together & then screwed to the outlet.

Cheers, this is pretty much what we do in the UK. I was taught to run the cable in one piece all around the ring leaving a loop of about 6" at each outlet location. It is then possible with UK standard twin + earth to loop out the bare earth conductor without cutting it (you still have to cut and twist the live and neutral). Not easy to do with the fully insulated cable that is the norm in Thailand.

I agree Crossy. If you have the time (not many contractors do) to not cut the earth and to strip the insulation from an unbroken section of this wire, this is by far the "best practice". Essentially, wire stripping & twisting WAS an essential part of technical college training for all apprentices. I know some Aussie contractors who are unable to strip & twist wire correctly. They seem to think that it is trivial & unimportant. On the otherhand, I have rescued many a household from a potential fire because wires have not been stripped or twisted correctly. I'm sure you'll agree.

What did you think of the 'Checking & Testing' doc? PM me please.

[elkangorito]

The next update will be about extension leads & the use thereof.

Don't forget! All things discussed here can be seen on one website;

http://www.crossy.co.uk/wiring/

[elkangorito]

The latest update.

[Crossy]

The latest update.

Website updated to include the extension leads data, thanks Elkangorito

To answer your queries (I've included it here because it is useful to all):-

Thai sockets are wired with Live on the Left looking into the socket with the ground pin at the top. For those with poor spacial awareness that means live is at the top when ground is on the right.

NOTICE TO BRITS, this means that those 'multi-plug' adaptors will have live and neutral transposed if you insert a UK plug, not really a problem with the block power supplies, but if you have an appliance with a standard UK plug the fuse will end up in the neutral line, not good.

Also remember the polarity when you replace your UK plug with a re-wirable Thai plug.

Unpolarised two-pin sockets are variable polarity (even in the same room). But many 2 pin outlets are the US polarised type, the narrow pin is live, the wider pin is neutral.

Edited May 17, 2006 by Crossy

[johng]

Extension cords are prone to physical damage. Periodically check the extension cords by running your hand along the entire length of it. If you feel any discrepancies, inspect the area. If the extension cord has a cut in it or an obviously compressed or distorted section, replace it immediately

I know its stating the obvious, but the extension cord shouldn't be inspected like this while its live ie plugged in to the mains

[Crossy]

Extension cords are prone to physical damage. Periodically check the extension cords by running your hand along the entire length of it. If you feel any discrepancies, inspect the area. If the extension cord has a cut in it or an obviously compressed or distorted section, replace it immediately

I know its stating the obvious, but the extension cord shouldn't be inspected like this while its live ie plugged in to the mains

John. Well at least it shows someone is reading our stuff

It's EXACTLY this type of constructive comment we need.

Website will be fixed immediately.

EDIT Site fixed

Any other comments are of course welcome.

Edited May 17, 2006 by Crossy

[elkangorito]

Extension cords are prone to physical damage. Periodically check the extension cords by running your hand along the entire length of it. If you feel any discrepancies, inspect the area. If the extension cord has a cut in it or an obviously compressed or distorted section, replace it immediately

I know its stating the obvious, but the extension cord shouldn't be inspected like this while its live ie plugged in to the mains

John. Well at least it shows someone is reading our stuff

It's EXACTLY this type of constructive comment we need.

Website will be fixed immediately.

EDIT Site fixed

Any other comments are of course welcome.

Thanks John. This is EXACTLY the sort of feedback we need. Neither myself nor Crossy are perfect & it's always a help to refine the ultimate objective...ZERO ELECTROCUTIONS.

[Boon Mee]

Well at least it shows someone is reading our stuff

I've been reading your stuff for a while now Crossy and you deserve a big thanks from everyone who has or will be employing this good advice.

[johng]

Thanks to the both of you ( Crossy + elkangorito ) for gathering all this info into one place.

I'm not an electrician but have received quite a few shocks in the past

I just wanted to comment that, 2 out of the 3 places that I've rented in Thailand don't even have a consumer unit !!! there's just a wooden box on the wall concealing a mass of wires just twisted together and wrapped in insulating tape ( not even conection blocks ) they must be extremely dangerous not just an electrical hazard but a fire hazard too.

[Crossy]

Thanks to the both of you ( Crossy + elkangorito ) for gathering all this info into one place.

I just wanted to comment that, 2 out of the 3 places that I've rented in Thailand don't even have a consumer unit !!! there's just a wooden box on the wall concealing a mass of wires just twisted together and wrapped in insulating tape ( not even conection blocks ) they must be extremely dangerous not just an electrical hazard but a fire hazard too.

John, it's just that type of installation we are trying to eliminate.

I'm gathering photos for a 'Rogues Gallery" to put on the site, do you mind if we use your piccies (please) ??

Meanwhile, if anyone else has photos of Thai electrical "installations" that we can use please either PM to myself, or post them here for all to wonder at.

[johng]

I'm gathering photos for a 'Rogues Gallery" to put on the site, do you mind if we use your piccies (please) ??

Yes of course you can use the photo's....

Here's another one that makes me laugh ( I know I shouldn't laugh )

everytime I go past the place.

[elkangorito]

I'm gathering photos for a 'Rogues Gallery" to put on the site, do you mind if we use your piccies (please) ??

Yes of course you can use the photo's....

Here's another one that makes me laugh ( I know I shouldn't laugh )

everytime I go past the place.

I must say that the data/voice cables passing through the roof space of the building is innovative but those 'low to the ground' high tension lines are a definite worry

[elkangorito]

Here is a suggested alternative to those ugly & dangerously exposed TPS cables running down your walls.

This is a subject that will be added to later.

[elkangorito]

Here is a suggested alternative to those ugly & dangerously exposed TPS cables running down your walls.

This is a subject that will be added to later.

Please be advised that the above attachment is intended ONLY for individual Domestic Installations...NOT condo's, apartments or industrial installations.

[elkangorito]

Coming soon...The appropriate use of PVC conduit in a Domestic installation.

[robint]

Hi Crossy

Ive been doing a bit of scouting around. Its all very well saying that the MEN or PEN system is the safest, but it relies on everyone in the area including the electricity authiority to implement this system. Its no good just going it alone otherwise you may well attract other people earth faults. Personally I ve never seen this implemented in the LOS, but it may well be in the case of new builds in BKK or pattaya? I think its a non starter not for the amateyur to meddle with.

An earth spike at least 2m long inserted into ground that is like to be permanently damp (eg near a cess pit or water storage/ rainwater drainage) is essentail

Critical areas like the kitchen and bathroom Shower must be protected with an RCD. Ive seen them in Homepro for 3000 baht (Safe T Cut made in Tahiland!!!!!!!!!!!!!!!!!). Ive also seen The Square D type made to slot into their distribution boards - sounds a better bet and only a 1000 baht. Will try and look at this properly as it was locked away.

The bathroom hot shower must have its own separate earth wire going to the spike togetther with a breaker switch OUTSIDE the bathroom (why do they insist on putting it inside next to the shower unit - ludicrous)

Its possible now to convert over to a 3 pin socket outlet as shown in Homepro (dont know which standard this type conforms to but its common on PC equipment). Personally I would recommend removing all socket outlets from the lighting circuits and blanking them off with a new plate or a dummy switch if not available). Then a completely new set of 3 wire power circuit spurs can be added using surface mounted pvc trunking. This can make a neat job. (NB no ring mains as this relies on fused plugs) Then Replace the old knife switch junk with a new Square D Cartridge mcb system. Very neat. After much effort I found some re-wireable plugs for the 3 pin system.

I looked for HRC cartridge fuses in Homepro and saw something that might be such an animal with a 30 and a 60 amp rating (class H). It purports to be made in the USA but Im not ocnvinced yet and will do some more cross checking (no pun intended). You can also see the old fachined ceramic fuses that are nothing better than a glass wire fuse. They were probably a cheap chinese copy of what should have been a genuine hrc fuse but they have been around for a 100 years.

Throw out any old kitchen appliances that have accessible metal surfaces such as the cheap rice cooker. These are potentially lethal. Get the modern totally enclosed plastic variety. Plastic kettle hotpots are great and so on

NB Dont use an RCD on lighting circuits (replace any metal types with all plastic). Also not adviseable on a fridge (but dont go messy with the metal parts round the back.

Do use a separate RCD circuit to protect any outdoor/garage power circuits in case you use power tools

Swimming pools need special attent, cant be covered here, but I would let anything other than a 12 volt lighting system near it for example.

Off the top of my head I am not sure what is done with the filter pump - perhaps someone can advise

Personally I would consider isolating the pump before using the pool.

BTW as little as 8v from head to foot can be felt by a swimmer in sea water. You can get a tingle off a 12 v battery in a marine speed boat - I know. But swimming pool water is not nearly so conductive.

Any observations on swimming pool electrics please??

Edited May 22, 2006 by robint