Water Heater Questions, Important To Connect A Water Heater Electric System To Ground ?

[frenchFARANGbkk]

Hi,

Do you know if it's important to connect a water heater electric system to ground, or no more than a washing machine?

Because there is no ground connected to the condo !

I guess this is the same for most of the Thai, so it must be safe? :-)

Also, do you know if the electric cable going to the water heater must be big (thick) or any size is ok ?

Thanks a lot !

[yabaaaa]

Water and electricity together = death.

Is it important............. for me yes!!

[Crossy]

It is vital that your water heater (and washing machine) are properly grounded.

If there is no ground available then as an absolute minimum you should have an RCD (Safe-T-Cut) device to reduce the danger of death when you get a fault.

It is also vital that the correct size of cable is used to prevent the danger of fire from an over-heated cable.

EDIT Since this is now in DIY I've removed the bump our OP put on the other water heater thread.

[Lite Beer]

Moved to D.I.Y.

As said it is essential for it to be earthed (grounded)

This may help http://www.crossy.co.uk/wiring/protection.html

[frenchFARANGbkk]

Thank you so much, can you tell me if it's difficult to install a Safe T-cut and how much it cost ?

[frenchFARANGbkk]

Thank you so much, can you tell me if it's difficult to install a Safe T-cut and how much it cost ?

Can you tell me also who can do it for me ( homepro ?) and if the best it to to have ground + Safe T cut or just ground/earth alone is enough when available ?

[stgrhe]

Thank you so much, can you tell me if it's difficult to install a Safe T-cut and how much it cost ?

Can you tell me also who can do it for me ( homepro ?) and if the best it to to have ground + Safe T cut or just ground/earth alone is enough when available ?

I say that any electrical appliance in a wet room should have both a proper ground as well as a residual current device (RCD). A proper ground will only protect your house / apartment from fire while the RCD will save life should the worst happen. Do not compromise on your and your family's safety.

Edited because of a spelling error.

Edited November 9, 2009 by stgrhe

[lopburi3]

Actually they both can save your life - the ground should trip a circuit breaker before a person becomes the ground - and the RCI should trip is a short enough time to prevent death - use them together as both can fail. All point of use water heaters should have a built in RCI which should be tested monthly to prevent any crud buildup that might prevent breaker from triping (had a unit where this happened - newer models were re-designed to avoid). But as the main power line will not be protected by that RCI recommend another unit upstream. The Safe-T-Cut should be installed by an electrician as wires are hot and very dangerous where it is normally placed (input main line). Believe costs about 4-5 thousand baht but often can get home/apartment owner to pay part of it as they are a selling/renting point as well known here.

[Ohms]

Frenchfarang etc.

I had to write when I saw all these clowns answer your question! First of all beware of asking questions that can only be answered by a professional. I am a qualified Electrician and Maintenance Superintendant Offshore. To all you clowns that answered his question, if you dont know then then shut the #### up!

Flame Removed

I'll keep this very short and not bore you with the hows and whys but yes you need both, a earth or ground as our yankie friends call it and a RCD or ELCB as sometimes known. If your equipment isnt earthed/grounded properly then the RCD will not work correctly FACT!

To answer how big a cable you need then you need to know what load the equipment will will take, eg. if the boiler was rated at 5000watts then we know the voltage is roughly 220V the 5000 divided by 220 is 22.72Amp. You will now need to search the internet to find the 'current carrying capacity' of a cable to suit in this instance 2.5mm square should suffice. This will all depend on the distance of your cable run, how it is run etc etc

For all the people who actually know what Im talking about, I know there are other factors to take into consideration like power factor correction etc but for his purpose this will be enough to allow him to safely calculate the correct cable size

Frenchfarag etc if you still need help then PM me. TIP be wary of people answering your post that have alot of posts behind their belt all it shows is that they like to talk alot about things they really have very little understanding about. These are the kind of people we would all avoid in the pub! ha ha

[Crossy]

Ohms.

With my Sparks hat on

A couple of observations:-

A modern domestic/industrial RCD / ELCB / GFI (or whatever we're calling it today) does NOT require a ground to function correctly. They work by comparing the current flowing in the line and neutral conductors, any imbalance of greater than 30mA (eg a flow through you) will drop the breaker and save your life. I am aware of marine systems with a floating neutral (although not expert), in these systems the operation of an RCD does require a ground, perhaps your offshore profession is clouding your knowledge.

Using 2.5mm² at >20A is really on the line, the cable will get pretty warm (although not enough to cause a fire), in a high ambient location such as Thailand using 4mm² would be a sensible option and allow for upgrade when you find your heater doesn't have the oomph in the cooler weather.

Why are you talking about PF correction, a heater is a resistive load so we have a PF of unity?

Just out of interest, we've had significantly more controversial threads on power supply in the 3 years since you joined, why choose this one to demonstrate your electrical knowledge, nobody has given any positively hazardous advice?

Now with my mod hat on

We welcome all professional sparkies (and plumbers, builders, roofers etc.) opinions when put in a clear and professional manner. However flaming and name calling achieves nothing and will not be tolerated.

[Ohms]

Oh god here we go like I said I wanted to keep it short but anyway your quite correct a RCD does monitor the current by using a ct on each conductor. Any imbalance trips the device but if not earth/grounded then there will be nowhere for the fault current to go therefore will only activate when you touch it. Hardly a protective device any longer! The horse has already bolted I would say, and really not how it was designed to operate But due to the small current involved you should be ok ha ha your call!

"30mA RCD" why 30mA because that’s what u always use? The 'monkey see, monkey do' ethos doesn’t work well with electrical installation. True they are the most commonly rated RCD for socket outlets etc but for equipment containing elements you will probably find a lot of nuisance tripping but reverting back to your interpretation on how it works by relying on it activating when you ground it yourself, then I can see where your coming from ha ha.

Using 2.5mm? Like I said it would probably suffice and was off the top of my head and did state to check current carrying capacity on the net or better still IEE Regs as that was used as an example only, also stated was dependant on how the cable was run. By that I mean, clipped direct, in conduit, bunched with other cable etc etc

Most engineers don’t allow for upgrades as they calculate that the equipment is already up to the job in the first place. Cant imagine if I had to install oversized cables on every item of equipment on an Oilrig incase I “needed more oomph in the winter” ha ha that was comedy classic! You made me smile after a hard day thanks!

Power Factor Correction? Your absolutely right, but as completely resistive loads are unheard of in my business then that was an oversite on my part. But Kudos to you and thank you for pointing that out

“Just out of interest”, As you seemed to be so interested in me, and thanks for checking out my profile but sorry you didn’t find anything there! The reason I don’t post much is that I have a life I don’t feel the need to spend every waking hour conversing with people through a computer. Even if I did I certainly wouldn’t admit to knowing every post on Thaivisa in the last three years on electrical installation/theory. Call me old fashioned but I like to do it the old way and actually meet people face to face, but ‘whatever yanks your chain’

If your answers prove anything it would be that you need to be commended on your ability to search wikipedia rather than getting a proper qualification on the subject you seem so passionate about, but its good to be passionate about something. How do I know your not qualified? I think you know better than to ask that question.

Actually I don’t know why I bothered in the first place. I don’t really like French people that much! But to put an end to this thread once and for all, Frenchfarang buy a gas heater and stop asking stupid questions! Touché!

No hard feelings Crossy ole chap!

[frenchFARANGbkk]

Thanks for replies, but don't worry, I also don't linke and don't speak to French people !

In my opinion what is stupid is using gaz in Thailand, but you might know what you are speaking about :-)

So the definitive reply is: Buy 4 mm cable for ground + RDC/Eartch breaker

Then do you know anyone who can install this for me ?

Thanks again for all.

[Ohms]

Ha ha frenchy great sense of humour!

But seriously I would suggest ole Crossy he he!

Let us know the load of your water heater in watts or kilowatts and we will be able to tell you what size of cable to use. It will be written on the specification lable. The 4mm cable was just an example.

ok?

[David006]

Thanks for replies, but don't worry, I also don't linke and don't speak to French people !

In my opinion what is stupid is using gaz in Thailand, but you might know what you are speaking about :-)

So the definitive reply is: Buy 4 mm cable for ground + RDC/Eartch breaker

Then do you know anyone who can install this for me ?

Thanks again for all.

Good grief what a verbose bunch....! Ground your home! Get a shower heater with a GFI ( don't think they sell 'em without. now) .and get somebod' to check you have a good earth/ground to your home. N American GFIs and Oz use the ground..here they don't downo..y? washing machines and kettles etc seem to have 3 pin plugs with only two pins.....

Ah yes... three deaths this month from electrocution in Trang province..no GFI no ground I assume !!! ...the local electrical inspectors just "passed" SIL new meter and entrance cables to her farm house with NO INSULATORS on the poles no GFI and a rats nest of house wiring ..go figure..

[Crossy]

washing machines and kettles etc seem to have 3 pin plugs with only two pins.....

Those are European 'Schuko' plugs, in France and Belgium the 3rd pin is part of the outlet and mates with the hole in the plug, in Germany and most of the rest of Europe the ground makes contact with the side strips on the plug.

HomePro have adaptors so that you can safely use these plugs with regular Thai grounded outlets, they look like this:-

You can also get proper Schuko outlets that fit a Thai back-box from the same place. Both the adaptor and outlets are under the brand name 'WonPro'.

[David006]

washing machines and kettles etc seem to have 3 pin plugs with only two pins.....

Those are European 'Schuko' plugs, in France and Belgium the 3rd pin is part of the outlet and mates with the hole in the plug, in Germany and most of the rest of Europe the ground makes contact with the side strips on the plug.

HomePro have adaptors so that you can safely use these plugs with regular Thai grounded outlets, they look like this:-

You can also get proper Schuko outlets that fit a Thai back-box from the same place. Both the adaptor and outlets are under the brand name 'WonPro'.

Thanks for that...interesting... wonder what the logic/safety aspect the design is based upon...

I was repairing our cheapie Panasonic Plastic dual tub washer (only has a two flat prong plug) and noticed both motors have ground bonding connected which go no place....same with our the fridges...ah well!

Not being experienced in HT distribution AC theory....anyone know what the resistance to ground of the "neutral" standard is? I suppose theoretically it should be the same as local ground since it is effectively that at the source. Also I noticed there is always a few ac volts to "ground" on the neutral ...ie a pd.( I have seen this in several locations in Thailand)! Suspect this is induced voltage only..the source of ground hum..?

[Crossy]

Thanks for that...interesting... wonder what the logic/safety aspect the design is based upon...

I was repairing our cheapie Panasonic Plastic dual tub washer (only has a two flat prong plug) and noticed both motors have ground bonding connected which go no place....same with our the fridges...ah well!

Not being experienced in HT distribution AC theory....anyone know what the resistance to ground of the "neutral" standard is? I suppose theoretically it should be the same as local ground since it is effectively that at the source. Also I noticed there is always a few ac volts to "ground" on the neutral ...ie a pd.( I have seen this in several locations in Thailand)! Suspect this is induced voltage only..the source of ground hum..?

The Schuko is a very safe design, the outlets are shuttered and the plug fits into a recess, it is impossible to contact live metalwork whilst inserting/removing the plug from the correct outlet, in both versions the ground connects first / disconnects last. As to why we get these on Thai appliances, who knows.

The neutral-ground connection at the transformer should be a few ohms if it has a proper earth mat. Your local ground spike will likely have a few hundred ohms, which is why an RCD is necessary, a L-E fault will not pull enough current to drop the MCB.

The N-E potential you're seeing is the volt drop along the neutral under load, the ground is at the same potential as the neutral at the transformer.

[InterestedObserver]

Ohms.

With my Sparks hat on

A modern domestic/industrial RCD / ELCB / GFI (or whatever we're calling it today) does NOT require a ground to function correctly. They work by comparing the current flowing in the line and neutral conductors, any imbalance of greater than 30mA (eg a flow through you) will drop the breaker and save your life. I am aware of marine systems with a floating neutral (although not expert), in these systems the operation of an RCD does require a ground, perhaps your offshore profession is clouding your knowledge.

In the US a residential GFI (GFCI) is required to trip at approximately 5 mA, see below from the National Electrical Code (NEC).

100.1 Definition

100.1- Definitions. Ground-Fault Circuit-Interrupter. A device intended for the protection of personnel that functions to de-energize a circuit or portion thereof within an established period of time when a current to ground exceeds the values established for a class A device.

FPN: Class A ground-fault circuit interrupters trip when the current to ground has a value in the range of 4 mA to 6 mA. For further information, see UL 943, standard for Ground-Fault Circuit Interrupters.

[Crossy]

In the US a residential GFI (GFCI) is required to trip at approximately 5 mA, see below from the National Electrical Code (NEC).

No argument there IO, I'm quoting UK regs ('coz that's what I know). Are ALL circuits required to be GFI protected as they are in the UK?

I would think a 5mA trip would cause significant issues with nuisance trips

30mA was chosen as being a happy medium between creation of a lethal shock and minimising false triggers.

[lopburi3]

I suspect that is why they are used on individual outlets and appliances rather than in panels from what little I have seen (not that much time is US during the last 40 years)

[InterestedObserver]

Are ALL circuits required to be GFI protected as they are in the UK?

I would think a 5mA trip would cause significant issues with nuisance trips

Not ALL residential circuits are required to have GFI (GFCI) protection. The US National Electrical Code (NEC) provides a list of eight (8) locations where 125 volt, single phase, 15 and 20 amp receptacles are required to have GFI protection for personnel; generally those locations that can get wet or damp, like a bathroom. Nuisance trips are not an issue with properly insulated household appliances, and the washer and dryer won't plug into the sized receptacles covered.

[Crossy]

Not ALL residential circuits are required to have GFI (GFCI) protection. The US National Electrical Code (NEC) provides a list of eight (8) locations where 125 volt, single phase, 15 and 20 amp receptacles are required to have GFI protection for personnel; generally those locations that can get wet or damp, like a bathroom. Nuisance trips are not an issue with properly insulated household appliances, and the washer and dryer won't plug into the sized receptacles covered.

Thought so, the sensible option

The IEE regs. 17th Edition require that all circuits in a domestic installation must have 30mA RCD protection at the board if the cable is buried less than 50mm deep in a wall or is not in a metal conduit. This along with the requirement to protect outlets where equipment MAY be used outdoors (so all downstairs outlets) effectively means that all circuits must be on a 30mA RCD or RCBO. We also must have split service boards so that a single fault won't take out all the lights.

[finner]

Don't know the Thai regulations regarding RCD's or GFI's but MAKE SURE YOU GET ONE ! The main breaker in our house is equipped with one and I thought it was a bit of overkill since I've been in the habit of following the local code in my country which specifies which type of circuit requires one, not the main.

Well here am I using the Thai made extension cord in the yard last week, barefoot of course, and did I get a jolt when I touched the back of the outlet which was a wall outlet on a cord and had some live screws exposed. Wondered why I wasn't dead till I happened to look at the 30 amp MAIN GFI breaker which had tripped and saved my stupid arse.

By the way, where do you get good female cord receptacles? All I've found so far are really good quality ones from the USA but they are rated at 125 volt.

Concerning OHM, had to laugh when he was telling us all how much he knew but was absolutely wrong about a GFI or RCD having to be grounded. One of their primary uses is in circuits where there is no reliable ground. They sense the difference between the current going out of the unit and the current returning to the unit. Nothing to do with ground except that's where the difference current went after it passed through me.

[Crossy]

Don't know the Thai regulations regarding RCD's or GFI's but MAKE SURE YOU GET ONE ! The main breaker in our house is equipped with one and I thought it was a bit of overkill since I've been in the habit of following the local code in my country which specifies which type of circuit requires one, not the main.

Well here am I using the Thai made extension cord in the yard last week, barefoot of course, and did I get a jolt when I touched the back of the outlet which was a wall outlet on a cord and had some live screws exposed. Wondered why I wasn't dead till I happened to look at the 30 amp MAIN GFI breaker which had tripped and saved my stupid arse.

By the way, where do you get good female cord receptacles? All I've found so far are really good quality ones from the USA but they are rated at 125 volt.

Glad to hear that an RCD has saved someone from a shock or even death

Regarding outlets and extensions, you certainly get what you pay for, Panasonic outlets and switches are good. The best IMHO are made by WonPro, definately not cheap but the best locally available stuff. Haco do a modular system which includes Schuko and Universal (that accept UK plugs) outlets, choose the combination of outlets you need for your particular location. We have mostly Panasonic, but with Haco in the kitchen for the kettle, grill and microwave and in the laundry room for the washing machine (all of which have Schuko plugs).

Your US leads and outlets will be just fine (said whilst getting out asbestos underwear), the amount of insulation required to give mechanical strength is far in excess of that required to provide actual insulation, the 125V rating is academic.

Ohms is obviously an intelligent and qualified industrial electrician, provided he keeps a professional hat on, realises the differences between an oil-rig and a domestic situation and can resist flaming other members he is welcome to add his input to any thread on TV.

[Crossy]

Well I hope it is within the rules to say that I am a qualified Electrician here in Bkk and will be glad to help you.....

Each situation is different here in LOS . The rules are broken in so many ways..a seeminly simple problem can be complicated.

I don't want to bore you with my experiences but it is not uncommon for the electricians here to run the neutrals off the breaker and the hot wires on the neut buss..so a well meaning beginner puts in a device thinking it will protect him and NO it does not. Jack

Nope, no rules broken Jack (although we'd rather you didn't use non-default font / colour settings), forum rules are here http://www.thaivisa.com/forum/boardrules.html

You are welcome to add your comments, we all make errors and several sets of eyes on a problem is best. I really do worry when some chap starts a thread with 'I know nothing about electrics, but how can I fix.......' but in the absence of half decent domestic sparks in Thailand (I know several excellent Thai industrial electricians) we have to try.

Do however remember that you're not in your home country, wiring techniques common there (eg UK ring-mains) may not apply here.

The general consensus is that in the absence of a coherent domestic installation manual we base our recommendations on the Aussie wiring regs, but like most things in this world, common sense rules

[david96]

RCD/RCBO 10ma Class 1 40 msecs trip max.

RCD/RCBO 30ma Class 2 300 msecs trip max.

Class 1 used in higher risk areas, such as dental surgeries and wet areas.(AS3003)

Standing leakage current should not exceed 30% of the rating of the protective device.

Under a sensitivity test they must trip between 50% and 100% of the rating of the device.

The actual test is at 100% of the rating of the device in ma to earth. There is also a test button on the units that will stimulate an out of balance current to check the operation of the device.

In practice most RCD/RCBOs will trip at about 70% of their rating in ma. at an average time

of 20 to 30msecs.

An RCD has no overload or short circuit rating and must be have a protective device, HRC fuse or MCB on the line side of the RCD.

An RCBO has overload and shortcircuit protection it is a combination MCB/RCD.

An RCD or RCD/RCBO will not prevent you receiving an electric shock but it will minimise the risk of death or severe injury by indirect contact as the victim is disconnected from the source of supply within milliseconds.

Electric shock can cause cardiac failure.

The Safe-T-Cut units available in Thailand are generally RCBOs but they may not comply with

IEC or AS/NZ Standards.

[frenchFARANGbkk]

Anybody can install RCBO in Bangkok ?

Thanks.

[Gulfstream]

Would an RCD/RCBO/ELCB Breaker in the Electric Service Box (Breaker Panel) work just as well as a Safety-T-Cut separate device?

Now having a condo upgraded with new Electric Service and cannot Earth for numerous reasons. Need protection for water heaters (as does OP), washer, and hob.

Planning to us an ABB brand in panel safety breaker. Any advice for or against this plan?

[stgrhe]

Would an RCD/RCBO/ELCB Breaker in the Electric Service Box (Breaker Panel) work just as well as a Safety-T-Cut separate device?

Now having a condo upgraded with new Electric Service and cannot Earth for numerous reasons. Need protection for water heaters (as does OP), washer, and hob.

Planning to us an ABB brand in panel safety breaker. Any advice for or against this plan?

That would be an even better solution than using the Safe T Cut, which by the way is a product I am not too impressive with. ABB has a hugh range of RCBOs for different applications and with different characteristics.

Their AC-types provides protection against overload and short-circuit currents; protection against the effects of sinusoidal

alternating earth fault currents; protection against indirect contacts and additional protection against direct contacts (I delta n=30 mA), while the A-types protection against overload and short-circuit currents; protection against the effects of sinusoidal alternating and direct pulsating earth fault currents; protection against indirect contacts and additional protection against direct contacts (I delta n=30 mA). However, the A-types for residential applications are not stocked in Thailand and ABB have recommended me to go for the AC-type.

Also, with regards to the different characteristics of operation ABB Thailand only recommend the C-characteristics to be used here. This should help you limit your search as the ABB pro M compact catalogue is almost 700 pages.

The below unit is the one ABB have recommended for my house that is under construction. ABB's distributor in Thailand is PMK Corporation Ltd. in Nonthaburi and their telephone number is 02 903 9999; e-mail: [email protected]

DS 951 AC type, C characteristic

In A Type code Order code EAN kg pc.

6 DS 951 AC-C6/0.03 16021351 413509 0.200 5

10 DS 951 AC-C10/0.03 16021369 413608 0.200 5

16 DS 951 AC-C16/0.03 16021377 413707 0.200 5

20 DS 951 AC-C20/0.03 16021385 413806 0.200 5

25 DS 951 AC-C25/0.03 16021393 413905 0.200 5

The DS9... series are 2-pole RCBO for 1L + N.

ABB pro M Compact catalogue can be downloaded here:

http://www.abb.com/AbbLibrary/DownloadCent...KMTdWVmHkmEigUH

Switch off auto proxy in your web browser before downloading as this catalogue is very difficult to download. It took me more than 10 tries before I succeeded.

Good luck

[Gulfstream]

Would an RCD/RCBO/ELCB Breaker in the Electric Service Box (Breaker Panel) work just as well as a Safety-T-Cut separate device?

Now having a condo upgraded with new Electric Service and cannot Earth for numerous reasons. Need protection for water heaters (as does OP), washer, and hob.

Planning to us an ABB brand in panel safety breaker. Any advice for or against this plan?

That would be an even better solution than using the Safe T Cut, which by the way is a product I am not too impressive with. ABB has a hugh range of RCBOs for different applications and with different characteristics.

Their AC-types provides protection against overload and short-circuit currents; protection against the effects of sinusoidal

alternating earth fault currents; protection against indirect contacts and additional protection against direct contacts (I delta n=30 mA), while the A-types protection against overload and short-circuit currents; protection against the effects of sinusoidal alternating and direct pulsating earth fault currents; protection against indirect contacts and additional protection against direct contacts (I delta n=30 mA). However, the A-types for residential applications are not stocked in Thailand and ABB have recommended me to go for the AC-type.

Also, with regards to the different characteristics of operation ABB Thailand only recommend the C-characteristics to be used here. This should help you limit your search as the ABB pro M compact catalogue is almost 700 pages.

The below unit is the one ABB have recommended for my house that is under construction. ABB's distributor in Thailand is PMK Corporation Ltd. in Nonthaburi and their telephone number is 02 903 9999; e-mail: [email protected]

DS 951 AC type, C characteristic

In A Type code Order code EAN kg pc.

6 DS 951 AC-C6/0.03 16021351 413509 0.200 5

10 DS 951 AC-C10/0.03 16021369 413608 0.200 5

16 DS 951 AC-C16/0.03 16021377 413707 0.200 5

20 DS 951 AC-C20/0.03 16021385 413806 0.200 5

25 DS 951 AC-C25/0.03 16021393 413905 0.200 5

The DS9... series are 2-pole RCBO for 1L + N.

ABB pro M Compact catalogue can be downloaded here:

http://www.abb.com/AbbLibrary/DownloadCent...KMTdWVmHkmEigUH

Switch off auto proxy in your web browser before downloading as this catalogue is very difficult to download. It took me more than 10 tries before I succeeded.

Good luck

Thanks Stgrhe, good info and bought 2 of the ABB safety's today, only one type was sold and has 30mA sensitivity. The shop confirmed

your suggestions are quite correct.