TN-C-S or TT?

[somersetsparks]

Patronising i'm not!! You must work for the only DNO in the country that strips out complete local network distribution cables and replaces with new, along with all the branch lines joints off to the householders service cut-out. And if they Do, ....not to the point, where 99.9% of the area's LV network distribution cables have been replaced, or have been fully PME'd....

Patronising you are i'm afraid, although you have a huge knowledge, the way you deliver it is very argumentitive and egotistical IMO
Well in built up areas, PME is 99.9% available, In fact in the large town I live in, there is barely a property were it isnt available, millions have been spent in the last 10 years doing service renewals, there are still paper leads around but almost all have been PME'd. There was a huge program to upgrade the overloaded network which is now essentially complete.

 

[Engineer54]

Patronising you are i'm afraid, although you have a huge knowledge, the way you deliver it is very argumentitive and egotistical IMO
Well in built up areas, PME is 99.9% available, In fact in the large town I live in, there is barely a property were it isnt available, millions have been spent in the last 10 years doing service renewals, there are still paper leads around but almost all have been PME'd. There was a huge program to upgrade the overloaded network which is now essentially complete.

You can read into, what and how i deliver my posts anyway you like, i have no control at all on that score!!

But i will say it again, your DNO must be the ONLY one in the country digging up street by street to replace/renew existing PILC cables, in order to have PME distribution...

I wonder if anyone else here, knows of any such DNO programme that is going on, or has been completed in there neck of the woods??

 

[somersetsparks]

You can read into, what and how i deliver my posts anyway you like, i have no control at all on that score!!

But i will say it again, your DNO must be the ONLY one in the country digging up street by street to replace/renew existing PILC cables, in order to have PME distribution...

I wonder if anyone else here, knows of any such DNO programme that is going on, or has been completed in there neck of the woods??

Well I only no what goes on in our area, I'm guessing you have checked with all the other DNO's in the country, so I won't bother to argue the fact.

 

[Engineer54]

Well I only no what goes on in our area, I'm guessing you have checked with all the other DNO's in the country, so I won't bother to argue the fact.

You may think i'm having a pop at you, but i'm not!!

What i do know, is that what your describing makes for economic nonsense. Even the cost of PME'ing every joint on an existing street distribution cable, would be prohibitive, against a zero monetary return, to what are now all private companies, that has shareholders. All they will want to see, is their shares increase in value and dividends increase.... I can understand PME'ing overhead LV distribution lines, as they are relatively cheap to convert, compared to underground street network distribution systems.

If as you say, this has been done by your area DNO, then the residents and businesses should consider themselves very lucky indeed....

 

[somersetsparks]

You may think i'm having a pop at you, but i'm not!!

What i do know, is that what your describing makes for economic nonsense. Even the cost of PME'ing every joint on an existing street distribution cable, would be prohibitive, against a zero monetary return, to what are now all private companies, that has shareholders. All they will want to see, is their shares increase in value and dividends increase.... I can understand PME'ing overhead LV distribution lines, as they are relatively cheap to convert, compared to underground street network distribution systems.

If as you say, this has been done by your area DNO, then the residents and businesses should consider themselves very lucky indeed....

You are right, they won't just decide to rip out a whole towns PILC cables but after numerous faults in particular streets etc. and the need for extra capacity for the fast growing town (doubled in last 40 years), I suppose it became necessary to do? Not all streets are done obviously and even where they are any branches etc. have usually been left. I can only speak for the town I work in and its immediate area and I'm certainly not in a management role, more of a grunt on the ground, always found it fascinating to watch the jointers joint to PILC though, such a skill.

 

[Cbigfoot]

Well that's not completely true at all. So what do you think happens when a TN-S supply is converted to TNC-S/PME??
They will only use crimped connections when a joint is replaced, they certainly aren't going to replace every joint on the distribution supply run before converting a households service head. It maybe several years before a converted distribution cable is fully PME'd, and is more likely than not, supplying both TN-S and TNC-S during that period.

By the way, there is nothing wrong at all, with soldered joint connections, they have been around long, long before crimped connections, they are as sound as any crimp connection too. There are very few circumstances where soldered terminations are not advised or permitted...

Ok, I must have misunderstood, i thought we were talking about overhead supplies here. The OP was talking about OH and so i have continued in that same area. I have never seen an underground supply that is TT unless the incoming earth has been lost at the joint underground. I would not expect a DNO to replace its cables underground just to implement PME, and i have not experienced a TNS service converted into PME without the service being replaced. In my areas if a TNS service is moved within a property they leave it as TNS and do not convert it to PME

I was not talking down soldered joints or connections, and yes i agreee there are many that are still in service and will be for years. However most DNO have moved over to crimp or more accurately shear off connections because of time and cost factors, but also they have a lower failiure rate than soldered joints. Now before everyone gets on thier soap box, i am not saying this is my point of view but that of the DNO i worked for and the jointers and linesmen who were using them on the cables that i spoke to and asked about it.

It was also the policy of SSE at one point that they would replace the old bare conductors with an insulated bundled service wherever possible, and then use concentric down to the head. If the main OH service was not easy to replace they would still replace the bare conductors into the property with concentric and when it was connected to the existing OH main Shearoff would be used. That would replace all connections along the length of the main; once all services had been connected, it would be staked down and labeled as PME.

 

[trev]

I have never seen an underground supply that is TT unless the incoming earth has been lost at the joint underground.

They must be fairly common, we have an underground supply and we're on a TT.

 

[Cbigfoot]

They must be fairly common, we have an underground supply and we're on a TT.

Fair enough! maybe its area specific, dependant on the original DNO way back when........

 

[Geordie Spark]

They must be fairly common, we have an underground supply and we're on a TT.

Aye ... me 'nall .... at me old hoose in Gateshead & Wor Lass's hoose in Sooth Shields.

 

[SPARTYKUS]

They must be fairly common, we have an underground supply and we're on a TT.

Thats just a great example of the vastness of detail and differences across areas. There are many combinations and permutations.

It's a big subject and to have seen it all & know it all would be some going.

 

[Guitarist]

Thats just a great example of the vastness of detail and differences across areas. There are many combinations and permutations.

It's a big subject and to have seen it all & know it all would be some going.

That's why we value E54 so highly