Earthing

[RF Lighting]

I take it you don't have many dealings with YEDL

 

[dingbat]

RF's right. Call that number, tell them you appear to have no earth, tell them you've been told this is dangerous and you'll find that YEDL will, quick as a flash, be round in 6-12 weeks.

Get a job reference. They will do it for free, but they won't actually make the final connection between MET and consmer unit.

 

[Shift]

Thanks for the advice everyone I've reported the Dangerous situation to YEDL as suggested, asked about resolving the situation in 24hrs and was told that they are not obliged to supply PME but will as a goodwill gesture in other words they will do it when they get round to it. Like you said RF Lighting they dont give a stuff.

I know the splitload (30ma rcd) CU I've bought will still be suitable if it turns out my system can be converted to TNS but if it has to be a TN-C-S system will it still be ok.

 

[Spark123]

Are you aware of the diffenences between TN-S and TN-CS and the requirements?

 

[eds_taff]

Please could someone explain why the cu will not be suitable for a TT system?

 

[davy_owen_88]

TT supplies require a separate 100mA time delayed RCD to protect lights/immersion heaters/etc. and a 30mA RCD for sockets likely to supply power to appliances used outdoors.

 

[Spark123]

The old CU does not have any RCD protection.

The new one will only have a switched incomer, needs to be an 100mA time delayed RCD incomer ideally for TT although this can be installed in the meter tails in a separate enclosure.

 

[eds_taff]

Great thanks for that.
I have some problems of my own then which I will start a new thread about.

Cheers

 

[securespark]

Did you disconnect MEB's when testing Ze?

If not, then do so & retest. It may be that you have nothing off that earth on the conduit and your earth connection is actually via the service pipework. This has never been allowed (in the case of gas pipes) and not been allowed since 1966 (in the case of water pipes).

 

[Shift]

Are you aware of the diffenences between TN-S and TN-CS and the requirements?

Yes just had a look at the on site guide, TN-S just uses the incoming outer sheath via a clamp as its earth and TN-C-S uses the neutral, an RCD works by tripping when there is current going to earth so if the neutral doubles as the earth there will always be some current going to neutral/earth so will continually trip the RCD. I think thats correct so I hope they will be able to convert to TNS.

 

[DESL]

an RCD works by tripping when there is current going to earth so if the neutral doubles as the earth there will always be some current going to neutral/earth so will continually trip the RCD.

Er No - RCD detects the difference between current on L & N on LOAD side not supply

 

[Spark123]

Nope, the N-E connection is done by the DNO at the supply head, as this is pre RCD it will not cause an imballance in the currents in the phase and neutral of the RCD coils hence it is not a reason for it to trip.
What I meant is are you aware of the differences in the requirements, i.e. the earthing and bonding requirements?

Bah, beaten by DESL lol

 

[Shift]

Did you disconnect MEB's when testing Ze?

If not, then do so & retest. It may be that you have nothing off that earth on the conduit and your earth connection is actually via the service pipework. This has never been allowed (in the case of gas pipes) and not been allowed since 1966 (in the case of water pipes).

There isn't any MEB's connected.

 

[Shift]

Sorry for my ignorance as you know there are large holes in my knowledge.Thanks for that Spark 123 and DESL so the CU will be ok then.The only difference I can see in the on site guide is the note at the bottom of the page where it states ''local electricity supply network conditions may require larger conductors'',is that what you mean.

 

[dingbat]

I hope they will be able to convert to TNS.

They won't. You'll get PME, like everybody else!