TN-S & TT on same installation what should I class it as?

[Miketwinny]

got a 16mm earthing conductor from main supply sheath goin in to the MET + an earth electrode(rod) next to the supply with a 10mm earthing conductor comin off it to the MET
Should I class it as a TT system for test results and mark the EIC as TN-S & TT :nonod:

 

[SPARTYKUS]

Jeysuz I can't hardly believe what I'm seeing. - someones driven an earth rod in but an inch from the service mains and the gas mains......

thats more of a worry!

 

[SPARTYKUS]

Btw it would be TNS. THATS the best earthing system. Hard line back to the tranny!

 

[SPARTYKUS]

Did you test the Ze? What was the TNS Ze?

im just wondering now why on earth that rod is there

 

[telectrix]

seen a few like that. and don't worry about the services, he's only driven the rod in half way;LOL.

 

[Miketwinny]

No tests done yet, been like that from new; 43 years.If the Ze for the TN-S system is OK, I can make the rod redundant.

 

[Guest55]

theres every chance its a dno bodge , seen dafter things done by power companies.
either way , tn-s is by far the better earth path and should be given precedence over tt.

 

[Silly Sausage]

Could you smell any gas there?
That looks distinctly like a meter union seal lying next to the rod, seen a few of those before! :wink_smile: :smilielol5:

 

[Rockingit]

Maybe at some point in the past (or from new) the Ze simply wasn't good enough so to lower it or there was a 'long time to fix' fault they knocked a rod in. If it's been concreted/screeded in like that from new suggests to me it got put in when you could see what was going on underneath.

 

[Miketwinny]

no gas problem been like that for 43 years

 

[markythesparky]

is the main switch an RCD? cant be a TT if its not.

 

[tigi]

My advice is not to make any judgement call on this one. Call in your local supply authority to address this HORROR show
or u could get egg on your face, they can confirm TNS max 0.8 ohms or TNCS max 0.35 ohms for your Ze's
They are normally very helpful and it should be free of charge
Let us all know the outcome

 

[bigbaddave]

got a 16mm earthing conductor from main supply sheath goin in to the MET + an earth electrode(rod) next to the supply with a 10mm earthing conductor comin off it to the MET
Should I class it as a TT system for test results and mark the EIC as TN-S & TT :nonod: View attachment 17960[/QUOTE

**** me...If this is the way he creates a earth then I think it would be safer without... Close or What

 

[Stroppy]

My advice is not to make any judgement call on this one. Call in your local supply authority...They are normally very helpful and it should be free of charge

From what I've read on here if you phone them up and mention an earth stake they think you are talking about an eco-friendly slab of beef.

 

[trev]

Tell you what Tigi, you must be very lucky and have gotten through to the one person at the local DNO who actually knows what you're talking about and how to help you. Every time I've done it round here I get the image of that Little Britain character...Computer says naw

 

[tigi]

Nice one Trev
That Little Britain character wouldn't be !!!!
Have a good evening

 

[wildgoose]

It's takes brave or stupid man to knock a rod in so close to the incoming services!!

On the subject of the earthing. I would first verify that there was a good TNS earth of less than 0.8ohms. If so, then run a new 16 mm earth up to the CCU from the MET and do away with the TT earth altogether as it is not needed.

 

[JD6400]

got a 16mm earthing conductor from main supply sheath goin in to the MET + an earth electrode(rod) next to the supply with a 10mm earthing conductor comin off it to the MET
Should I class it as a TT system for test results and mark the EIC as TN-S & TT :nonod: View attachment 17960[/QUOTE

**** me...If this is the way he creates a earth then I think it would be safer without... Close or What

You think that was close !!!
One of our lads had a wee mishap this morning while installing a stake on a local farm .
It was a 3ph 35mm incomer before he literally blew it clean apart on all 3 phases , the supply side was still live when they got to us !
I knew it was going to be painful when the first two vans turned up but my arse near on gave out when the other three turned up !!!!!!!!!!!!

 

[sparkymalarky]

Horror show!!!

However, I can withdraw two positives from this!

1. It didn't happen on a Friday afternoon.
2. Tomorrow is Friday.

 

[sparkymalarky]

Surely you had a wee peak at that Tx between the shed and the pole? Would yer man not have figured that the cable didn't dissipate through the atmosphere and that it was most likely underground? lol.

 

[wildgoose]

You think that was close !!!
One of our lads had a wee mishap this morning while installing a stake on a local farm .
It was a 3ph 35mm incomer before he literally blew it clean apart on all 3 phases , the supply side was still live when they got to us !
I knew it was going to be painful when the first two vans turned up but my arse near on gave out when the other three turned up !!!!!!!!!!!!


View attachment 18005View attachment 18006View attachment 18007View attachment 18008View attachment 18009

That was bad luck!

Now the question we are all wanting to ask - who pays??

 

[GLENNSPARK]

My advice is not to make any judgement call on this one. Call in your local supply authority to address this HORROR show
or u could get egg on your face, they can confirm TNS max 0.8 ohms or TNCS max 0.35 ohms for your Ze's
They are normally very helpful and it should be free of charge
Let us all know the outcome

so you would just go with this would you....rather than get a measured value eh?
LOL....

 

[Knobhead]

Could you smell any gas there?
That looks distinctly like a meter union seal lying next to the rod, seen a few of those before! :wink_smile: :smilielol5:

You running the gas meter backwards at the weekends then Archy?

 

[JD6400]

That was bad luck!

Now the question we are all wanting to ask - who pays??

I have already assumed the position and await delivery of the bill while firmly gripping my ankles , with out even a hint of any Vaseline in sight !!!!:blush2:

What do you reckon it will be then ?

A builder we work with hit two only a few months apart last year on a local estate we work for , i think the first was £7000+vat and second was £5500+vat !:dunce2: But in fairness they were both HV underground and not LV like this one .

 

[Miketwinny]

Re: TN-S & TT on same installation what should I class it as?

is the main switch an RCD? cant be a TT if its not.

No RCD protection on the installation.

 

[Miketwinny]

got a 16mm earthing conductor from main supply sheath goin in to the MET + an earth electrode(rod) next to the supply with a 10mm earthing conductor comin off it to the MET
Should I class it as a TT system for test results and mark the EIC as TN-S & TT :nonod: View attachment 17960[/QUOTE

**** me...If this is the way he creates a earth then I think it would be safer without... Close or What

been like that from new 43 years no problems guna do a Ze test soon.

 

[JD6400]

Surely you had a wee peak at that Tx between the shed and the pole? Would yer man not have figured that the cable didn't dissipate through the atmosphere and that it was most likely underground? lol.

It was actually some form of voltage suppressor and not a Tx apparently but that is besides the point , just thought i would throw that in as even the jointer's had not seen one before !

 

[sparkymalarky]

ballpark figure? £750 - £1500? assume to replace cable & labour etc.

 

[JD6400]

I am hoping for something under £2500 , the more under the better !

 

[wildgoose]

I have already assumed the position and await delivery of the bill while firmly gripping my ankles , with out even a hint of any Vaseline in sight !!!!:blush2:

What do you reckon it will be then ?

A builder we work with hit two only a few months apart last year on a local estate we work for , i think the first was £7000+vat and second was £5500+vat !:dunce2: But in fairness they were both HV underground and not LV like this one .

I'm afraid you just can't call it until the bill arrives. On an optimistic note there have been a couple of instances recently where my DNO have charged nothing ?? One was a serious moving of the incoming power so that the client could have the incoming service moved. Cable excavated with mini digger, cut, jointed and extended. All FOC - was Very impressed.

Fingers crossed then