Does this alright to you?

[La Poste]

This is my sisters place.

I did an ELI test and it came out 0.6 Ohms but I heard a strange sort of burning welding sound coming from the CU.

When I tested again the ELI had dropped to 0.4 Ohms and stayed stable after that.

I tested again this weekend and no strange noises with an ELI of 0.4 Ohms.

Her RCD in the board had stopped working and it was impossible to move the on/off switch, it was totally stuck solid.

I replaced the RCD, tested it and all works OK but I'm not happy with the strange noises and erratic readings.

Any thoughts?

 

[Engineer54]

Probably that RCD contacts welding themselves together... Now it's been replaced, it should be fine now!!

 

[Deleted member 19807]

that dose not look like a DNO's earth i suspect it should be TT'ed, with RCD main switch.

 

[La Poste]

It looks like an old TN-S system to me, you can see the old earth wire sweated onto the supply outer sheath on the right hand side of the supply cable.

 

[Engineer54]

that dose not look like a DNO's earth i suspect it should be TT'ed, with RCD main switch.

You have obviously no experience of old DNO cut-out's to come out with a statement like that!!! You would actually do away with a TN-S with a 0.4 Zs for a TT system that you would be happy with a 200 ohm Ra ?? The mind boggles??

 

[Deleted member 19807]

a yellow crimp on a screw might be normal in hong kong but not here, i would rather have upfront type s rcd on TT over that botch up. you obviously have no idea about TT installations.

 

[Deleted member 19807]

View attachment 7747View attachment 7748

This is my sisters place.

I did an ELI test and it came out 0.6 Ohms but I heard a strange sort of burning welding sound coming from the CU.

When I tested again the ELI had dropped to 0.4 Ohms and stayed stable after that.

I tested again this weekend and no strange noises with an ELI of 0.4 Ohms.

Her RCD in the board had stopped working and it was impossible to move the on/off switch, it was totally stuck solid.

I replaced the RCD, tested it and all works OK but I'm not happy with the strange noises and erratic readings.

Any thoughts?

was this faulty rcd the main switch?

 

[La Poste]

No it's a single RCD board 30ma.

The RCd covers the socket outlets on one side of the board.

The lights etc on the other side of the board are not RCD protected.
It definitely does not have an RCD main switch.

I agree with you about the crimp and screwed earthed, it seems a bit unreliable to me.

 

[Deleted member 19807]

you could contact the DNO and see if they know what earthing you should have and if its TNS they may come and sort it out (probably not)

personaly I would TT it and either put an upfront 100mA s type in or RCBO the lighting etc. I normally get under 50 Ohms on a rod or 2

 

[La Poste]

Why would you want to TT it?
I mean what do you see wrong with this arrangement?
Thanks.

 

[Engineer54]

a yellow crimp on a screw might be normal in hong kong but not here, i would rather have upfront type s rcd on TT over that botch up. you obviously have no idea about TT installations.

Really, ....Then that's the second foolish statement you've made!! Makes you wonder how La poste ever managed to read that 0.4 Ze doesn't it!! But you would rather put your faith in an RCD just like the one La poste had to replace above ....Right??

If you don't like the present earth connection at the DNO cu-out, then crimp a suitably sized earth cable to the sweated DNO cable earth for gods sake. You don't by-pass a perfectly ''good'' TN-S earth for a sub-standard TT system!! ...Or would you??

 

[Engineer54]

Why would you want to TT it?
I mean what do you see wrong with this arrangement?
Thanks.

There is NOTHING WRONG with it!!

 

[La Poste]

I like the idea of joining both earth cables together at the same screw terminal.
The supply cables sweated earth wire and the house earth cable.
Just to make the connection more solid and reliable.

 

[Deleted member 19807]

Why would you want to TT it?
I mean what do you see wrong with this arrangement?
Thanks.

That is not an official DNO earth, its a home made one, probably done by someone who thinks they are an engineer, ask the DNO to give you an official earth (which they won't) only other proper option you have wothout interfering with DNO equipment (which you can't do) is to supply your own earth, the only earth you are allowed to supply is a TT.

 

[Engineer54]

That is not an official DNO earth, its a home made one, probably done by someone who thinks they are an engineer, ask the DNO to give you an official earth (which they won't) only other proper option you have wothout interfering with DNO equipment (which you can't do) is to supply your own earth, the only earth you are allowed to supply is a TT.

Haha!! ...absolutley Unbelievable!!!