harmonistaion is the fault of everything

[steptoe]

spotted on the blog of a self appointed 'expert'  

Before harmonisation, this earthing system was termed PME, or Protective Multiple Earth on the consumer side of the installation, and term that is still in common use, even though, strictly speaking, it may not always apply to it’s post-harmonisation cousin, TN-C-S.

so apparently, TN-C-S suddenly appeared after harmonisation, prior to that it was all PME, and suddenly its not?

surely it was always TN-C-S  and started to become PME as the DNOs upgraded their networks,

as per what I posted once here

nothing to do with harmonisation from my understanding , or is it?

 

[Tony S]

We had TN-S or TT when I started. TN-C-S and PME were a cost cutting exercise.

I’ll be honest, until I retired and joined an electrical forum I didn’t know other systems existed. BS7671 didn’t apply to my line of work at the time.

Other than my own house (TT) everything was TN-S in my world. I put enough transformers in to know about the single N→E link in TN-S systems.

 

[Lurch]

nothing to do with harmonisation from my understanding

Concur wholeheartedly.

I remember years ago trying to explain to everyone that 'TN-C-S is not PME'. Now no-one even knows what any of these things are.

 

[binky]

trouble is how the hell can you tell the difference when out on a job, apart from the odd DNO sticker?

 

[Lurch]

trouble is how the hell can you tell the difference when out on a job, apart from the odd DNO sticker?

Isn't it all PME now?

 

[Andy™]

Isn't it all PME now?

not always, it sometimes lacks the M

PME is always TNCS. TNCS is not always PME

 

[Tony S]

not always, it sometimes lacks the M

PME is always TNCS. TNCS is not always PME

No wonder we’re confused!

 

[Lurch]

not always, it sometimes lacks the M

PME is always TNCS. TNCS is not always PME

I know all that, obviously. What I meant was I thought that the network was now all PME, as in they have been adding lots of earthing points so all the TN-C-S is now PME by default. Can't remember where I read it, might have something referred to on here once. Might have also been slightly unofficial.

 

[steptoe]

I've never seen them dig up any joints just to rod them.

Usually only for a new supply, or fixing something, then they PME it.

 

[kerching]

NICEIC AC Around here always puts TNS as TNCS as CS stands for cable sheath :slap

 

[sprocketflup]

Lol what does he think the TN is for?

Totally (k)nackered Cable Sheath maybe

 

[kerching]

He is a gob  w

Scrapes through his annual,assessment through bull     And ...

cannot find a pair of plums

 

[apprentice87]

I know all that, obviously. What I meant was I thought that the network was now all PME, as in they have been adding lots of earthing points so all the TN-C-S is now PME by default. Can't remember where I read it, might have something referred to on here once. Might have also been slightly unofficial.

I had a bit of a rant about it once... So far as I am concerned just about ALL supplies [i mean houses and the like] are TNCS/PME now. Perhaps not from the advantge side of things, but definitely from the downsides of the thing [I nearly said negative side of things then!!]

What i mean is, everytime the dno repair a service joint. or connect up a new supply, they link the neutral of the cable to the cable sheath, AND, [if they can be arsed] put in a rod as well.

So, you might like to think you have a proper TNS supply and so, "supply neutral faults will not affect me!!" but you would be wrong, you will be just as dead as your neighbours WITH a PME supply as THEIR neutral, is now most likely connected to YOUR exposed conductive parts...

john

 

[binky]

great! :facepalm:

 

[steptoe]

I had a bit of a rant about it once... So far as I am concerned just about ALL supplies [i mean houses and the like] are TNCS/PME now. Perhaps not from the advantge side of things, but definitely from the downsides of the thing [I nearly said negative side of things then!!]

What i mean is, everytime the dno repair a service joint. or connect up a new supply, they link the neutral of the cable to the cable sheath, AND, [if they can be arsed] put in a rod as well.

So, you might like to think you have a proper TNS supply and so, "supply neutral faults will not affect me!!" but you would be wrong, you will be just as dead as your neighbours WITH a PME supply as THEIR neutral, is now most likely connected to YOUR exposed conductive parts...

john

you see my problem is this John,

I like you,

you have a wealth of knowledge to share

then you come out with an idiotic comment like this, :shakehead

what part of TN-C-S is not PME is it you are misunderstanding?

and then the bit about 'are all PME'  .?!

just about every supply out there is anything but PME, unless it was installed in the last 5 years or so.

a proper PME requires an earthed N just before it enters the property,

I'd reckon that only happens on new supplies,

as for earthing every joint,,,,, what do you really think?  :C

btw, negative would be fine, you only have negative on a DC supply 

 

[binky]

so proper PME would have a rod just beofe the house that is clearly easy to find and identify???? ray

Changing tack slightly, how about discussing the pros and cons of assuming everything is PME or T-N-CS?

 

[steptoe]

so proper PME would have a rod just beofe the house that is clearly easy to find and identify???? ray

Changing tack slightly, how about discussing the pros and cons of assuming everything is PME or T-N-CS?

not necessarily,

just as every joint doesnt have a 'rod'

usually just a 'pigtail'

stick your own rod in, and put a notice at the incomer, thats what I have done, [minus the notice] , havent got round to a proper notice yet.

LOCALISED PME IN SERVICE

would about do it

 

[misssweden]

I've never seen them dig up any joints just to rod them.

That would be one way to make the footpaths look like a patchwork :slap  

 

[steptoe]

That would be one way to make the footpaths look like a patchwork :slap  

you can dig up my footpath anytime you want, 

 

[misssweden]

you can dig up my footpath anytime you want, 

Thanks darling, you paying the council for the opening notice? I guess you don't have a streetworks ticket so I'll have to sort out chapter 8.