no earth

[xbeazt]

Hi everyone

 

[bigbaddave]

What the meaning of your title?

Welcome to the gang BTW

 

[kingeri]

That was random, but hello nevertheless.

 

[xbeazt]

Just testing that the forum works OK.


Ive recently been appointed as the tester for a company which deals mainly with domestic properties. Having only ever tested my own installations on commercial / industrial installs, Ive never had any issues regarding the incoming supplies. However, when carrying out an EICR on a property I have failed to gain an acceptable reading for Ze or PEFC. I have the original test certs which confirm the prescence of an earth. I have informed the supplier who inform me that a team will be out to rectify the issue. This was last year and I am getting a little concerned that nothing has been done yet. Can anyone point me in the right direction as what I should do next ?

Cheers guys.

 

[xbeazt]

I will keep you all posted after I send a letter to the company.

 

[Des 56]

They would normally just fit an rcd to tide things over till they get around to sorting the problem
Is the installation Rcd protected ?

 

[Boatelec]

Ayup xbeazt. You don't say what sort of a supply it is or what you mean by no earth. How high is the Ze? There are a number of areas round here NWarwickshire+Leics with Ze considerably higher that the the normal 0.35 for TNCS and 0.8 for TNS and there is nothing you can do about it apart from complain to the supplier and fit an RCD. I do a lot of work on farms and out of the way locations on overhead lines. These are normally TT and it is normal to find Zes way up in the tens. At risk of telling you something you already know. Is it possible yours could be a TT? Sometimes its not immediately apparent where the supply comes in in SWA and looks like an incomer with an earth connection. I normally fit an Rcd and talk to the customer about getting the supplier in to make a TNCS connection on to the neutral.
Howard

 

[sparkless]

what type of supply?

 

[Plonker 3]

I wouldnt use a previous test certificate to find out the type of earthing system used. If it is a PME or TN-S supply and the Ze is above the set limits then contact the DNO who have a responsibility to maintain the earth connection. They should attend within a specifed te limit too if it is too high for the type of esrth connection.

If it is a TT then you will need to fit the relevant RCDs as stated above and also ensure the Ra value is satisfactory.

 

[xbeazt]

The installation is a TNS system. The previous test sheets show an acceptable reading of 0.38 ohms for Ze and my reading is 283 ohms. The earth strap connected to the incomer has clearly been on for some time. The board is a 16th edition split load with just the ring mains on two breakers and Ive just installed a separate board for a new kitchen extention but cant complete the certs until I get a main earth.

Does anyone know the reason for having no earth. Its obviously at the transformer end.

 

[chrish_1977]

How long ago was the last inspection done, can't see it jumping so high unless the problem was there the last inspection and they couldn't be bothered to investigate. I would double check it definitely isn't tt. From that reading that's what I would be looking for. If not contact dno and let them know what you have tested and the reading you have

 

[Plonker 3]

If it is a TN-S you need to contact the DNO asap as they have a resonsibilty to maintain it and should act as a emergency call out. No need to worty futher once they have been contacted as it then becomes there liability but it wolud be worth advising the customer to turn off there DB until it has been repaired to a saisfactory state.

 

[xbeazt]

I can clearly see the earth strap on the outer sheath of the main incomer which comes from the ground up. All the surrounding properties are of the same design. On Monday I will make my 4th phone call to the supplier, they also confirmed the supply type on my initial phone call and are aware that there is an immediate issue. I was also under the assumption that it was treated as an emergency and would be sorted pretty swiftly. The main issue is that this property is used as a care home for mentally ill people. But the suppliers dont seem to care at all.

 

[Des 56]

The installation is a TNS system. The previous test sheets show an acceptable reading of 0.38 ohms for Ze and my reading is 283 ohms. The earth strap connected to the incomer has clearly been on for some time. The board is a 16th edition split load with just the ring mains on two breakers and Ive just installed a separate board for a new kitchen extention but cant complete the certs until I get a main earth.

Does anyone know the reason for having no earth. Its obviously at the transformer end.

One or other of these statements needs explaining
If there is a high resistance earth,the chances are they have repaired or renewed a cable somewhere along the line,as stated previously,their action would be to fit an rcd as a temporary measure,it may be that the supply has been converted to Pme and that facility is available

Whether its them or you.an rcd needs to cover those unprotected circuits. Couldn't you shift the mcbs over for now or fit a rcd instead of the main switch

It seems to be an issue for them to solve, but at the same time,it is yours or your customers responsibility to make the installation safe,even if only temporary

 

[xbeazt]

And the main fuse is still a 3036 in the old cast iron enclosure which needs to be upgraded anyway

 

[xbeazt]

I meant " an acceptable reading " rather than " no earth ". I will be shifting the breakers to the RCD side tomorrow.

 

[Engineer54]

I can clearly see the earth strap on the outer sheath of the main incomer which comes from the ground up. All the surrounding properties are of the same design. On Monday I will make my 4th phone call to the supplier, they also confirmed the supply type on my initial phone call and are aware that there is an immediate issue. I was also under the assumption that it was treated as an emergency and would be sorted pretty swiftly. The main issue is that this property is used as a care home for mentally ill people. But the suppliers dont seem to care at all.

When you phone the DNO again ask for the persons name and position whom you are talking too!! Re- affirm that this will be the 5th time of calling and that the installation in question is a mental care facility. Might even be better to ask to speak to the area manager responsible...

If what your saying is correct, in that you have a Ze of 283 ohms (then something is very wrong and can only deteriorate further) then they should be treating this call as an emergency attendance. Make it known to the DNO person on the other end of the line that you WILL take things further if they fail or refuse to address their obligations to maintain their equipment!!

 

[xbeazt]

Cheers 54. I will ring tomorrow.

 

[xbeazt]

Just a quick update to let everyone know what happend.

The supplier came on Friday and installed a new cut out. They also found it odd that there was no presence of an earth and on further inspection realised that earth clamp that was on was only connected to the armouring of the incomer and not to the lead sheathing also. Anyway I nice new cut out has been installed and I can finish the testing.

Now my next concern is to do with the previous test certs that I have which clearly state a figure for maximum measured Zs for the circuits. This could not be possible unless it was calculated and Ze was aquired by enquiry.

Surely there is some misjustice here as the lads fitting the cut out said the earth strap had been like that for some time and was in no way connected properly.

What is everyones thoughts on this matter and what / if any action should be taken ?

 

[Geordie Spark]

Just a quick update to let everyone know what happend.

The supplier came on Friday and installed a new cut out. They also found it odd that there was no presence of an earth and on further inspection realised that earth clamp that was on was only connected to the armouring of the incomer and not to the lead sheathing also. Anyway I nice new cut out has been installed and I can finish the testing.

Now my next concern is to do with the previous test certs that I have which clearly state a figure for maximum measured Zs for the circuits. This could not be possible unless it was calculated and Ze was aquired by enquiry.

Surely there is some misjustice here as the lads fitting the cut out said the earth strap had been like that for some time and was in no way connected properly.

What is everyones thoughts on this matter and what / if any action should be taken ?

Well the first thing I would do is present my invoice for the work I've done.

 

[xbeazt]

Believe me, at the end of the month, the only thing that concerns me is putting my invoice in and receiving my sweet sweet hard earned pennies

 

[Geordie Spark]

Believe me, at the end of the month, the only thing that concerns me is putting my invoice in and receiving my sweet sweet hard earned pennies

Good lad.

All you can do is make sure that your work is spot-on and that you get paid for doing it so that you can a) sleep with a clear conscience and b) pay for the food on your table.

Whatever other folk have done on the job before you arrived is something you have little or no control over and you'll probably find if you try to "do something about it" nobody is interested.

Keep up the good work & stay safe.

 

[Engineer54]

Just a quick update to let everyone know what happend.

The supplier came on Friday and installed a new cut out. They also found it odd that there was no presence of an earth and on further inspection realised that earth clamp that was on was only connected to the armouring of the incomer and not to the lead sheathing also. Anyway I nice new cut out has been installed and I can finish the testing.

Now my next concern is to do with the previous test certs that I have which clearly state a figure for maximum measured Zs for the circuits. This could not be possible unless it was calculated and Ze was aquired by enquiry.

Surely there is some misjustice here as the lads fitting the cut out said the earth strap had been like that for some time and was in no way connected properly.

What is everyones thoughts on this matter and what / if any action should be taken ?

So how did the DNO connect the main earth conductor to the the lead sheath?? Or is it now a PME connection??

 

[xbeazt]

They just cut back the armouring and bonded the clamp to the lead outer sheathing and applied a resin to the exposed area.

 

[Engineer54]

They used a BS 951 earth clamp or other clamp?? Or did they solder the earth conductor to the lead sheath??

 

[telectrix]

They used a BS 951 earth clamp or other clamp?? Or did they solder the earth conductor to the lead sheath??

just what i was wondering. be nice to know...... OP????

 

[xbeazt]

From what I saw it was just a 951 clamp and a tar like resin from a mix. I will take a picture tomorrow and post.