Ground Earthing and an RCBO

[Pumpuynarak]

Can somebody please tell me what an RCBO is ?

 

PS - If you want your helicopters engine replaced or a business plan drawn up then i'm your man, get my drift lol

[transam]

Just now, Pumpuynarak said:

But THESE PEOPLE as you kindly put it are not ALL electricians and have little or no knowledge of how a house should be wired me included. I bought a new house in 2007 from a very large local builder and trusted that they would do the job properly, i knew no different after living in Thailand for 3 months.

 

Thats why in my home country the UK has proper regulations to ensure that new build houses are built to the required standard to protect the inhabitants from such things as electrocution.

 

If Thailand's does'nt have the required regulations and ENFORCE them then THEY should accept responsibility for any such deaths imo

 

Just sayin like lol

 

PS - Having lived here for 17 years now i am fully aware of Thailands shortcomings but still get surprised EVERY DAY.

Think I read somewhere that all new builds in LOS have to be earthed.

 

My house was built in 2007 too, the builders were dumbfounded at my earthed 3 pin socket request, I did get through in the end, even an earth at light fittings.

But, the biggest, dumbest thing they did, which I only found out by accident, and at a different house of a friend on an estate was, the A/C & showers do not go through the consumer unit, they are earthed, but there is nothing to trip.

 

I replaced all the wall switches to them with Haco trip switches, had to do it with the live......????

[TimeMachine]

18 minutes ago, OneMoreFarang said:

Sure, you can fit it.

But will it work efficiently without earth wiring to the outlets?

Yes. Has nothing to do with earth. If there is a difference between just the two wires of usually about 30ma then the breaker will switch regardless of earthing or no earthing.

[brianthainess]

27 minutes ago, Pumpuynarak said:

If Thailand's does'nt have the required regulations and ENFORCE them then THEY should accept responsibility for any such deaths imo

All new builds for the last 5+ yrs have regulations, PEA came to my house and checked the earth rod in the ground, before changing the meter from building charge to domestic charge meter. Some other changes all power cables to the house from the meter, must be clamp connected, not twisted wires with a bit of tape, and any underground cable must be twin copper triple insulated to your power board.

[Muhendis]

21 minutes ago, lopburi3 said:

But RCBO does not require ground to operate and save lives.

An RCBO looks at the difference between currents flowing in the live and neutral wires.

Depending on the setting of the sensitivity of this device the RCBO will trip if a current of 30milliamps to 10 milliamps is flowing more in one wire than the other.

This minute current can flow through a body and cause the RCBO to trip thus disconnecting power before harm is done. Earth is not needed for this. The person who contacts the faulty equipment is quite likely grounded enough.

[TimeMachine]

4 minutes ago, Pumpuynarak said:

Can somebody please tell me what an RCBO is ?

 

PS - If you want your helicopters engine replaced or a business plan drawn up then i'm your man, get my drift lol

The R refers to Residual current. The current entering the house live wire must equal the current in the neutral wire.  I.e. what goes in must go out through wires and not through someone's body to earth ground. If for instance your hand absorbs the current down to ground the current of live and neutral won't match and the breaker trips. The O refers to the breaker having the usual Over current protection also. So if currents match but is over a certain amount it will also trip because maybe too many devices on that breaker taking too much current. There are important other specs to each type of device. YouTube vids a plenty.

[quake]

19 minutes ago, TimeMachine said:

You don't need earth for rcbo. That's what's so fantastic and why it's so important when there is no earthing. 

Yes your correct.

But much better to have the complete system earthed as well.

And that may well,  require a rewire of all the house out lets. 

[Pumpuynarak]

13 minutes ago, brianthainess said:

All new builds for the last 5+ yrs have regulations, PEA came to my house and checked the earth rod in the ground, before changing the meter from building charge to domestic charge meter. Some other changes all power cables to the house from the meter, must be clamp connected, not twisted wires with a bit of tape, and any underground cable must be copper triple insulated to your power board.

Thankyou, i'll get PEA to come round to my gaff and check, i know for a fact i don't have an earth rod.

[KannikaP]

1 hour ago, TimeMachine said:

Why would new cabling be needed around the house? Just rewiring of switchboard .

Surely if there is only 2 core cable connecting the sockets to the fuse box (Consumer Unit) then those cables will need replacing. Lights are OK. Showers and air cons need their own feed and circuit breaker.

[brianthainess]

1 minute ago, Pumpuynarak said:

Thankyou, i'll get PEA to come round to my gaff and check, i know for a fact i don't have an earth rod.

????⚡????

[brianthainess]

Just now, KannikaP said:

Showers and air cons need their own feed

Most showers have their own RCD and won't produce any hot water if not earthed. 

[KannikaP]

Just now, brianthainess said:

Most showers have their own RCD and won't produce any hot water if not earthed. 

Thanks, I shall check on mine.

[Pumpuynarak]

8 minutes ago, brianthainess said:

Most showers have their own RCD and won't produce any hot water if not earthed. 

Interesting, my showers are relatively new (2 years old) and recently i got a tingle when i switched on. I immediatley switched it off and tried it again later, no problem.

[xylophone]

3 hours ago, cooked said:

It took me two years to find out that someone had swapped the wire colours halfway along the cable run. 

Yes, I found the same in a couple of friends houses here, when they had some electrical problems and asked me to come round to check them out. I've also witnessed it on extensions being added to houses here, whereby the "electrician" will use up any spare cable laying around the place, to complete a circuit, thereby making it damn near impossible for anyone to know which cable is which when it comes to the outlet.

 

Luckily enough I was a bit cautious with the house I first bought here, and wanted to change the large old-fashioned wall mounted circuit breaker in the bedroom, so I got the girlfriend to go downstairs to the distribution board and switch off the breakers one by one, and when that didn't work I told her to turn off the main switch on the distribution board, thinking I would be okay.........but I decided to just check the circuit breaker with my volt meter, only to find it was still live, despite all the power in the house being turned off!!!!!

 

Turns out the builder had tapped into the main cable coming from the outside pole to the distribution board (using tape and twisting the cable), so this particular circuit breaker and air con would always be live!

 

Check, and double check – – it may save a life.

[bluejets]

19 hours ago, OneMoreFarang said:

Often this would require completely new cabling all over the house.

I don't see why that would be.

An RCBO can be fitted to any existing circuit.

[motdaeng]

17 hours ago, Pumpuynarak said:

Interesting, my showers are relatively new (2 years old) and recently i got a tingle when i switched on.

I immediatley switched it off and tried it again later, no problem.

i would not using this shower anymore until the heater and

the electrical systems have been checked!

 

 

[lopburi3]

1 hour ago, bluejets said:

I don't see why that would be.

An RCBO can be fitted to any existing circuit.

Actually most in Thailand are main breaker panel type rather than the individual circuits/outlets often used elsewhere.  Often fitted after main breaker to home for protection on all circuits.

[Pumpuynarak]

20 hours ago, Pumpuynarak said:

Thankyou, i'll get PEA to come round to my gaff and check, i know for a fact i don't have an earth rod.

I say that cos i can't see any earth rod anywhere around the house like i used to see on my UK houses, is it possible i could have one that i can't see ?

[lopburi3]

3 minutes ago, Pumpuynarak said:

I say that cos i can't see any earth rod anywhere around the house like i used to see on my UK houses, is it possible i could have one that i can't see ?

Yes - many have grounded neutral at electric poles - about every 3rd pole will have a ground wire running down it.  If your main breaker panel has a link between ground strap and neutral buss that is what you should have.  But not everywhere has that system so you need to check.

[TimeMachine]

3 hours ago, Pumpuynarak said:

I say that cos i can't see any earth rod anywhere around the house like i used to see on my UK houses, is it possible i could have one that i can't see ?

Yes. I couldn't find mine in oz. Electrician was stumped. One day after cleaning out a drain opening I noticed the copper pipe with wire attached to it. 

They can be in inconspicuous places. 

[Muhendis]

3 hours ago, Pumpuynarak said:

I say that cos i can't see any earth rod anywhere around the house

Builders in Thailand often locate the earth rod under the house where you can't access it. 

To verify it's existence, simply stick a bit of rebar into the ground close to the house, disconnect the house from utility supply and with a cheap multimeter set to read Ohms, measure the resistance between CU earth and rebar its should be no more than a few ohms.

[digbeth]

What happens to RCBOs in cases where there are no central ground but some appliance has their own ground? in many Thai house without ground wiring, there are often grounds from the appliance chassis to the nearest ground or metal bit of the house, like hot water heater, air con units or washing machine to oven, would this complicate thing should one fit an RCBO or RCCD? 

it is advisable to rip these separate 'grounds' out if one were to rewire the house

[JBChiangRai]

On 9/23/2023 at 12:29 PM, Pumpuynarak said:

Interesting, my showers are relatively new (2 years old) and recently i got a tingle when i switched on. I immediatley switched it off and tried it again later, no problem.

I am not a fan of instantaneous water heater for showers.  We always fit stored water heaters typically 55 to 150 liters.

 

I had a condo in Pattaya with them, when I sold it, the buyer phoned me a few months later and said he got a tingle when showering if the lights in the TV room were on. It never happened to me because the lights were never on in my TV room when I was showering.

 

I suggested 2 possible solutions first, and my recommended solution, get it checked out by a sparky and second, don't shower with the TV lights on.

[lopburi3]

4 minutes ago, digbeth said:

What happens to RCBOs in cases where there are no central ground but some appliance has their own ground? in many Thai house without ground wiring, there are often grounds from the appliance chassis to the nearest ground or metal bit of the house, like hot water heater, air con units or washing machine to oven, would this complicate thing should one fit an RCBO or RCCD? 

it is advisable to rip these separate 'grounds' out if one were to rewire the house

No effect on RCBO and add protection as any serious leak to ground in appliance will trip a normal circuit breaker.  Only remove such grounds if you actually wire appliance to electric box ground.

[Crossy]

6 minutes ago, digbeth said:

What happens to RCBOs in cases where there are no central ground but some appliance has their own ground? in many Thai house without ground wiring, there are often grounds from the appliance chassis to the nearest ground or metal bit of the house, like hot water heater, air con units or washing machine to oven, would this complicate thing should one fit an RCBO or RCCD? 

it is advisable to rip these separate 'grounds' out if one were to rewire the house

 

RCDs or RCBOs (RCDs with over-current protection) will work just fine with multiple earths or even with no earth.

 

If you are re-wiring it would be wise to wire to the current Thai standard of a central rod and a N-E (MEN) link in the consumer unit (this assumes that your local distribution system has the neutral earthed every 3rd pole or so).

 

 

[digbeth]

On 9/23/2023 at 11:51 AM, transam said:

Think I read somewhere that all new builds in LOS have to be earthed.

 

My house was built in 2007 too, the builders were dumbfounded at my earthed 3 pin socket request, I did get through in the end, even an earth at light fittings.

But, the biggest, dumbest thing they did, which I only found out by accident, and at a different house of a friend on an estate was, the A/C & showers do not go through the consumer unit, they are earthed, but there is nothing to trip.

 

I replaced all the wall switches to them with Haco trip switches, had to do it with the live......????

bigger loads like hot water heater and aircon are usually run separate from the consumer unit, with separate breaker to prevent the it tripping the whole house back in the day as these appliance would be late addition and the aging consumer unit in the house probably wont have the space or main breaker able to handle the load, the electrician that did your install probably did it out of habit without knowing why

[transam]

15 hours ago, digbeth said:

bigger loads like hot water heater and aircon are usually run separate from the consumer unit, with separate breaker to prevent the it tripping the whole house back in the day as these appliance would be late addition and the aging consumer unit in the house probably wont have the space or main breaker able to handle the load, the electrician that did your install probably did it out of habit without knowing why

My A/C, less than 1000w, shower, 4500w, can a 32 amp consumer unit deal with this...?

Strange how back home, everything went through the consumer unit...

[lopburi3]

7 minutes ago, transam said:

My A/C, less than 1000w, shower, 4500w, can a 32 amp consumer unit deal with this...?

Strange how back home, everything went through the consumer unit...

New AC are much less power hungry and smaller units seem to just have plug to insert into normal outlet.  In the past there were no breaker panels - just a plywood panel with main fuse and a couple fuse knife switches.  AC was wired direct to a breaker/switch next to unit.  Heaters to breaker/switch outside bathrooms (you turned breakers off when not in use).

 

As for 32 amp feed being enough - probably - but depends on what else you may be using at same time (refrigerator/stove/toaster/pot/lights/fans/etc) - as a general rule would be best to upgrade to the larger meter normal 60 plus amp service that most homes use if they have more than fans/lighting.

[transam]

8 minutes ago, lopburi3 said:

New AC are much less power hungry and smaller units seem to just have plug to insert into normal outlet.  In the past there were no breaker panels - just a plywood panel with main fuse and a couple fuse knife switches.  AC was wired direct to a breaker/switch next to unit.  Heaters to breaker/switch outside bathrooms (you turned breakers off when not in use).

 

As for 32 amp feed being enough - probably - but depends on what else you may be using at same time (refrigerator/stove/toaster/pot/lights/fans/etc) - as a general rule would be best to upgrade to the larger meter normal 60 plus amp service that most homes use if they have more than fans/lighting.

The problem is with not going through a consumer unit here, you have a mass of live wires you cannot isolate, there is no way of turning these feeds off, so if a loft fire, rats, you are stuffed.

Again, back home we have an incoming service cut off switch, which covers everything.   ????

[lopburi3]

5 minutes ago, transam said:

The problem is with not going through a consumer unit here, you have a mass of live wires you cannot isolate, there is no way of turning these feeds off, so if a loft fire, rats, you are stuffed.

Again, back home we have an incoming service cut off switch, which covers everything.   ????

That was then - these days most homes do have proper main and sub breakers for everything - but electricians are learn on the job and, as with most of us, don't like to change once we learn one way of doing things.