Need help in earthing arrangement

[107]

Hello guys,

hope you all keeping well. I'm new bird on this forums as this is my first post thread. Anyway, one of my customer saying, after every visit from British Gas engineer they always saying 'you don't have suppler earthing in your property. pls sort this out ASAP.'

When i went on site to do initial inspection, I checked main cut out unit. and i can see earth wire coming out from main incomer city cable. Please see my attached picture for your reference.

So why BG engineer keep on saying NO SUPPLER EARTHING? I know the best way to check by performing Ze test, but I'll get my multi meter back after two weeks. And i have to quote him in two days.

If any of you come across with this kind of installation (see picture) and what you did to solve the problem? (earth rod installation, bonding to water n gas pipe, asking energy provider for Ze??) it would be really help full, if I can little bit of advice please. To be honest i never seen installation like this, particular in earthing arrangement.

Many Thanks.
107.

 

[Deleted member 26818]

Am I missing something, but the picture appears to show an earth braid attached to the sheath of the incoming cable?

 

[Guest55]

Am I missing something, but the picture appears to show an earth braid attached to the sheath of the incoming cable?

agreed , tns was my assumption.

 

[GLENNSPARK]

it is TNS but a Ze would confirm it......
i thought it was obvious from the pics....hense my desent into childishness earlier.....

 

[trev]

There is indeed a braid attached to the sheath but nothing is impossible There could be a problem with the sheath of the cable (unlikely I know) or the BG guy could be talking total and utter shi.....erm nonsense. That's what I meant to say, nonsense

 

[Engineer54]

Generally the only thing a BG fitter will test anything with is a plug-in socket tester, so more likely there is an earth connection fault at the supplying socket outlet or somewhere else on the circuit!!

Not sure why the OP even went to look at this job, having been told of a possible fault that would almost certainly need test equipment to verify?? A jobbing electrician can't function without test equipment for Two Weeks. If your own equipment is off being repaired or whatever, then you need to hire, beg, steal of borrow, in order to be able to function/work surely??

 

[Silly Sausage]

I've got my neon screwdriver, what else do I need.

 

[SYKRAPS]

Ze at the incomer to verify connection and check that Gas and Water are bonded (this what the BG engineer has probably picked up on btw).

It could be the end of a shared supply and the earth to the sheath has been interupted upstream maybe.

Electrician making first post and going to perform testing with no test gear FFS, I would be embarassed to admit the fact publically.

Also the photo could do with showing where the connected earth cables are running too if you can update it please.

 

[bigbaddave]

107.. Does this refer to how many days you work without a tester??

 

[stonejenson]

The braided connection from the sheath suggests TNS, but what happens when there's no cable at all???
I wanted to change my own CU last year, began to look and couldn't figure out my own arrangement - no MET, no cable to Neutral (still have no idea how i was connected) - got supplier to come and look (do a PME check they said), they sent someone to replace supply head. While doing it, I said, I was after an MET and watched as the installer stripped the supply cable sheath, attached the braid and connected it directly to the main Neutral block! After it's taped up, you can't tell that I now have a TN-C-S/TN-S bizarre combination, which is an old way of doing it supposedly.
Now I've done my 2394 and 2395 I'm starting to look at doing more EICR's and again the first one I look at has no obvious earthing connection... here we go again!

 

[GLENNSPARK]

The braided connection from the sheath suggests TNS, but what happens when there's no cable at all???
I wanted to change my own CU last year, began to look and couldn't figure out my own arrangement - no MET, no cable to Neutral (still have no idea how i was connected) - got supplier to come and look (do a PME check they said), they sent someone to replace supply head. While doing it, I said, I was after an MET and watched as the installer stripped the supply cable sheath, attached the braid and connected it directly to the main Neutral block! After it's taped up, you can't tell that I now have a TN-C-S/TN-S bizarre combination, which is an old way of doing it supposedly.
Now I've done my 2394 and 2395 I'm starting to look at doing more EICR's and again the first one I look at has no obvious earthing connection... here we go again!

well if you knew anything much at all about inspection & testing then you would know that the PEFC and the PSCC on a TN-C-S will be largely the same and its that...that will give the game away as far as earthing arrangements that cant be visually verified is concerned...
you carry out ECRs?...lol..
forget the 2394/2395 until you can grasp basics like this...

 

[stonejenson]

well if you knew anything much at all about inspection & testing then you would know that the PEFC and the PSCC on a TN-C-S will be largely the same and its that...that will give the game away as far as earthing arrangements that cant be visually verified is concerned...
you carry out ECRs?...lol..
forget the 2394/2395 until you can grasp basics like this...

In my defense, perhaps I hadn't worded my post quite clearly enough - I couldn't figure out what earthing arrangement I had on my own installation at the time, as had no test equipment and was in the middle of my level 2 studies a good few years ago. Now having learned a lot more, yes, I know I can test to get a better idea as to what the situation is, but the first person that has asked me to do an EICR, while I was there to deal with other issues not related to electrical work, had no TN-S or TN-C-S set up that I could see, and has in fact, rather oddly for a semi detached house in the town centre, got a TT set up, with an earth stake mostly buried under a slab in the back yard. The point was it's hard to tell what's going on just by looking, and that I know there's going to be jobs like this in the future, when even if you think you know how it's arranged - you can still be wrong. I imagine even you have been confused at some point in your career.

 

[Engineer54]

The braided connection from the sheath suggests TNS, but what happens when there's no cable at all???
I wanted to change my own CU last year, began to look and couldn't figure out my own arrangement - no MET, no cable to Neutral (still have no idea how i was connected) - got supplier to come and look (do a PME check they said), they sent someone to replace supply head. While doing it, I said, I was after an MET and watched as the installer stripped the supply cable sheath, attached the braid and connected it directly to the main Neutral block! After it's taped up, you can't tell that I now have a TN-C-S/TN-S bizarre combination, which is an old way of doing it supposedly.
Now I've done my 2394 and 2395 I'm starting to look at doing more EICR's and again the first one I look at has no obvious earthing connection... here we go again!

And totally bloody Wrong!!

Why the hell did he attach the sheath to the neutral, when all he needed to do, for a PME connection is bring an earth connection out from the neutral block on the service head?? The guy's an out and out idiot!! I wonder if he even checked the cable Sheath, for a TN-S earth already being in place??

 

[stonejenson]

And totally bloody Wrong!!

Why the hell did he attach the sheath to the neutral, when all he needed to do, for a PME connection is bring an earth connection out from the neutral block on the service head?? The guy's an out and out idiot!! I wonder if he even checked the cable Sheath, for a TN-S earth already being in place??

You'd have to ask UK Power networks that one. I did see whilst doing my lev 3 studies a diagram that showed an older style arrangement for TN-C-S, where they attach an earthing clamp to the sheath, then to the MET, but not quite how they did it. At the end of the day, the earth path is the same as illustrated, with the addition of bonding the lead sheath, and if the sheath is unbroken along the whole supply run as a standard TN-S, then it's a kind of belt and braces thing I suppose.

With my installation as was, there was no connection to be found anywhere on the supply sheath, and no bonding to gas or water. (Nor any connection to supply neutral, and no earth stake) No earth cables other than the CPC's of circuits ran to the earth block in the old CU, bar one that went to a second CU upstairs, and again there, there was only the CPC's to circuits. It still remains a mystery.

 

[chopper76]

Anyway back to the British gas statement, are you sure the customer mis heard main equipotential bond- to the gas main?

 

[somersetsparks]

Good point chopski, I have seen plenty of those little notice things on gas meters, it usually means they couldn't see it without opening their eyes lol