Reverse Neutral/Live or has the Earth Rod Disconnected?

[Docmartin]

Got a new switchboard ?

Too many tiresome RCBO trips ?

No problemo !

Just wind back leakage protection !

30 mA is for weakling westerners.

We locals can handle 100 mA through the heart - we're used to it.

[Crossy]

21 hours ago, Crossy said:

 

You can make a lost-neutral detector using a regular RCD, there's a thread on the board somewhere.

 

 

Found the thread:-

 

 

[Metropolitian]

It could be worth checking the transformer at the street. If it is connected to earth.

 

I did check the transformer here, as I am changing the whole electric system here. New consumer units and wiring, getting rid of shared neutral wiring between groups and replacing the burned/eaten wires.

The consumer unit is a mess, the stand-alone breaker of the aircon in the front room is connected to the incoming wires and still live when the CU is shut off.

 

Want to make sure everything is ok, so I went for a walk to check if the neutral is a PEN. At the transformer I couldn't see anything connected to earth, and checked the foot of the pole and yes I see a wire to the ground, fixed to a bolt and then a wire to... it's cutted off!

 

I am going to inform at the electric company about this.

I think it should be a PEN system from outside and at home TN-C-S.

 

Anyway in any case PEN or not, with the non-earth-connection at the transformer,  the earthing rod outside the home has then only one function, capacitance earthing.

 

Maybe this is the cause with the OP, and at next door a leaking into ground.. sending those 35 volt (with very little milliamps) to your ground, or vice versa.

 

 

[Metropolitian]

The transformer. With the 3 incoming wires and star system L123+N

At the bottom, a earthing wire goes under and a piece of wire which is cut off (offscreen)

Fuzzy picture, sorry for that but there is almost visible that the wire is interupted.

 

I hope not that the 'engineers' think a bolt in the pole and the pole does the job.

Same as the old water heater in the shower here, earth wire just nailed in the wall, wall does the job. It amazed me years ago, now got used to this practice but at my place it will be by my regs.

 

 

 

 

[Metropolitian]

47 minutes ago, Metropolitian said:

I think it should be a PEN system from outside and at home TN-C-S.

Correcting myself.

TT with earth nulled and indoors "TN-C-S with PEN conductor" (The link between the neutral and earth busbar.)

 

 

Edited December 10, 2019 by Metropolitian
fixing writing error

[Crossy]

@Metropolitian can you check if the neutral is grounded at other poles, it should be at every 3rd or 4th pole for the Thai implementation of MEN (similar to PME in the UK).

 

That star point ground is a bit mangy to say the least, are you quite sure that's the only "connection"?  

[Metropolitian]

On 12/11/2019 at 5:15 AM, Crossy said:

@Metropolitian can you check if the neutral is grounded at other poles, it should be at every 3rd or 4th pole for the Thai implementation of MEN (similar to PME in the UK).

 

That star point ground is a bit mangy to say the least, are you quite sure that's the only "connection"?  

Today I went for a walk, to check the 24Kv transformer again and walking around in all the sois that's connected to this one transformer. It was a interesting walk as I walked to the main entrance of our 'muban noi' , at the front gate the soi has transformers too.

Ok, at that street (it's a part of our muban) the transformers do have earthing. And at the endpoints the neutral is earthed. (so not every 3 poles) Nothing in between these endpoint has N to PE link.

The same for the other side of that street.
Entering the muban noi again, looking at all the start and endpoints of the lines, nothing. At the transformer, I found a link at the transformer itself (on the backside) and after 2 meter it is cut off.

 

The transformer for our connection:

 

At the right bottom you can see the cable bolted to the transformer.

 

 

And again the same , with better light, photo from the wire at the bottom of the leg.

 

Just outside the street, other 'smaller' transformer.

Clearly seen the link from the casing to the ground

 

At the endpoints of the line at the consumers side.

That is the way how it should be.