Electric : ground and neutral connected

[leogerritsen]

Yesterday i was in Global House Pranburi and I saw this electric schema hanging.

[Kenny202]

Thats an earth leakage breaker system. Measures if there is any leakage between voltage going in (active) and going out (neutral). So for eg some voltage going to ground.... perhaps via you ....they will trip the circuit in 30 milliseconds. Very effective and a must for all homes used in conjunction with circuit breakers (which are more to protect cables for short circuits or overcurrent). Not a good idea to use on circuits for fridges or washing machines and Im guessing probably would get a lot of nuisance tripping on electric showerheads

[bankruatsteve]

It is the way Thailand implements "MEN".  

[Kenny202]

5 minutes ago, bankruatsteve said:

It is the way Thailand implements "MEN".  

I dont think they use a proper MEN system here. Neutral grounded to earth in your home but not on PEA side. Every place Ive owned here seem to get tingles off mant steel bodied applianes

[bankruatsteve]

4 minutes ago, Kenny202 said:

I dont think they use a proper MEN system here. Neutral grounded to earth in your home but not on PEA side. Every place Ive owned here seem to get tingles off mant steel bodied applianes

Well, from all accounts where it is implemented, they do it right.  Not all of Thailand has MEN and should not be connected as such in the CU unless that is known to be the case.

 

Edit: "Tingles" from class-1 appliance has nothing to do with MEN and all to do with ground system.

[sfokevin]

7 minutes ago, Kenny202 said:

I dont think they use a proper MEN system here. Neutral grounded to earth in your home but not on PEA side. Every place Ive owned here seem to get tingles off mant steel bodied applianes

Same here... My house is a relatively modern build and NONE of the 3 prong outlets have any wiring to the grounds... The PEA provides no ground either... I got tired of having to wear my flip flops to use my espresso machine and had a local sparky add ground wires in the kitchen receptacles to a ground rod.

[leogerritsen]

I see N and Earth connected, the breaker switches off Line and Neutral. But Neutral stays connected as if it is PE ? Isn't that dangerous ?

 

[Crossy]

8 hours ago, leogerritsen said:

I see N and Earth connected, the breaker switches off Line and Neutral. But Neutral stays connected as if it is PE ? Isn't that dangerous ?

It's no different to TNC-S / PME in the UK which few worry about. Back home you don't see the N-E connection as it's in the service head behind a seal.

 

There are potential (sorry) issues with an open neutral, but if you have a look at your poles you should see the neutral grounded to a rod at every 3rd or 4th pole. Combine that with every house having a rod too and that's a pretty good ground net, the neutral (and ground) isn't going far above earth potential.

 

I'm not overly happy with the earth being permanently connected to the incoming neutral so we have an isolator before the distribution board, open that and we are totally disconnected from the outside world.

 

Once you get past the MEA/PEA inspection (the MEN connection and rod was pretty much the only thing our inspector actually inspected) there's nothing to stop you converting to TT if that's what floats your boat.

 

[leogerritsen]

Thanks all.

I feel more confident now. I will make an isolator switch before the MEN.

I am very happy i got such a clear response from you guys !

[Peterphuket]

I'm searching of the color of the ground wire in Thailand.

I have here a cable with 3 conductors, black/brown and grey, I really can't find on the internet.

I know "Crossy" knows a lot, maybe he can help me?

Thanks in advance.

[johng]

Don't rely on the colors....check for yourself what is live or not.

But "normally" Black is live,
Grey is neutral and green is earth...but earth is a brown color so maybe thats your earth...but check it yourself.

[Peterphuket]

Thank you John, but it is a new cable, I have to use outside, I'm surprised, thy don't use the color green, but TIT.

[bankruatsteve]

11 minutes ago, Peterphuket said:

Thank you John, but it is a new cable, I have to use outside, I'm surprised, thy don't use the color green, but TIT.

Agree the colors don't make much sense for a 3-core cable.  Hopefully, it is UF grade or the like for use outside.  i would go with black for live, grey for neutral, and the brown for ground.  Maybe strip back the insulation so it is obvious as the ground.

[Crossy]

Yeah, I have some 3-core round cable that's black, white, red. It went against the grain but red is now ground (with a bit of green sleeving).

 

 

[Fruit Trader]

Brown black and grey are Euro three phase. Thailand likes an international mix in its electrical cables.

[Peterphuket]

10 minutes ago, Fruit Trader said:

Brown black and grey are Euro three phase. Thailand likes an international mix in its electrical cables.

That's interesting to know, it is 3x1mm square, and the brand is Yazaki, looks like Japanese?

But I'm not so familiair with that matter, but I suppose when it is use for three phase, it is missing a 4th conductor, or I'm wrong?

 

[Fruit Trader]

17 minutes ago, Peterphuket said:

That's interesting to know, it is 3x1mm square, and the brand is Yazaki, looks like Japanese?

But I'm not so familiair with that matter, but I suppose when it is use for three phase, it is missing a 4th conductor, or I'm wrong?

 

Yes that's correct if the neutral (blue) is not required in the Euro color scheme. A small three phase motor could be wired using 3x1mm cable with the ground delivered from elsewhere.

[lopburi3]

On 2/11/2019 at 7:37 PM, Kenny202 said:

Not a good idea to use on circuits for fridges or washing machines and Im guessing probably would get a lot of nuisance tripping on electric showerheads

That was the thinking but in 40 years of usage here have not had any such issues (and if I did would want to correct it) - as far as electric showers they have a built in unit and should also be attached to another upstream to protect the wire going to unit (never had an issue and have 6 heaters in operation).

[Led Lolly Yellow Lolly]

Every colour of the rainbow is used for 3-phases here. The only safe option is to verify the sequence yourself.

[leogerritsen]

I am the OP of this post. I thanked the contributors for their answers.

After that someone took over and changed the subject.

Why not open a new post ?

[Rimmer]

A post containing text in Dutch language has been removed