Retro marking cables in the German electrical Installation industry

Hi Both, appreciate the feedback.  The reading i undertook certainly levels out with your collective input.  But, the elephant in the room for me, away from the guardianship of the regulations, is the waste that this will generate.  As copper cable generally has stable conductive properties for many years, as long as the cable has not been under any due stress and has been free of chemical contamination. 

We talk about sustainability being the most important thing in our lives now, but it seems as though this one has been invited to the party...

Are you adding a new CPC, or a new neutral to effect the TNC-s conversion, and what is the colour of the existing PEN.
If it was in the UK one might be labelling it up as a known but non-dangerous exception to current rules in a legacy installation. (as a lot of older UK intake rooms and installations generally have something there that would not meet current practice ).
Germany used to have similar regulatory options, that allowed old installations to be kept running if safe even if not complaint to latest rules does it not any more ?
Mike.

mapj1 said:

If it was in the UK one might be labelling it up as a known but non-dangerous exception to current rules in a legacy installation. (

It depends on whether you take the repurposing of a green-and-yellow marked conductor as a live conductor to be a 'non-dangerous exception' from a safe working practices perspective.

Putting standards aside, I wouldn't want to be in a position of trying to justify the rights and wrongs of it in the case that someone got hurt afterwards, say if they mistook the purpose of the conductor.

I don't think this is a simple discussion.

Daniel Hardy said:

is the waste that this will generate. 

I agree this is a difficult discussion, the ethics of waste vs the ethics of duty of care for safety, and the cost of re-wiring replacement vs cost element in "so far as is reasonably practicable" in safety.

The operator of the installation will be responsible for ongoing safety ... what is their view?

I agree, especiall as we cannot see it, though I come from the direction that it is presumably currently functioning as a CPC, (as part of its PEN role) and it is green and yellow. Perhaps one should be adding a blue neutral alongside rather than a new Green yellow earth - but the installation is already a little odd in  having a blue third phase - with that, I'd have expected to see an old German style red earth in that case, though there should not be too much of that left these days, - or a second black, or the modern grey/white.

Mike.

PS as the German wiring  colour history is quite different to ours. Bis == until, siet ==since
rot red, grau grey, Schwarz black , Blau and braun are more or less phonetic.

Blue is not an official phase colour since 1965 - though like in the UK  there would be some over-run of projects already started.

I agree with your statement, that safety should always be the top priority and that is why only "competent people" should work on any electrical installation.  But In furtherance to the topic of the cable marking, it is possible to apply this in Germany, although not the preferred or recommended option; documentation being critical to the intervention and the lifespan of the installation 

Putting standards aside, I wouldn't want to be in a position of trying to justify the rights and wrongs of it in the case that someone got hurt afterwards, say if they mistook the purpose of the conductor.

Oddly though, we're still permitted to oversleeve another (live) colour with G/Y and use as a protective conductor - commonly done with 3-core SWA on single phase circuits (unless you can get hold of some of the Irish stuff) - which to my mind poses exactly the same risk, if for errors at the other end.

   - Andy.

AJJewsbury said:

Oddly though, we're still permitted to oversleeve another (live) colour with G/Y and use as a protective conductor - commonly done with 3-core SWA on single phase circuits (unless you can get hold of some of the Irish stuff) - which to my mind poses exactly the same risk, if for errors at the other end.

Consider someone tapping into an existing cable run to install a new appliance.

If they try to connect to a phase, but it's actually an earth, then that's pretty harmless.  If they try to earth the new appliance, but it's actually live, then that's an accident waiting to happen.

Or, even for the use of a simple test-lamp type voltage indicator. If you connect the device to what you think is the protective conductor, and accidentally come into contact with the other end ...

There is a school of thought that we ought to be able to rely on the protective conductor.

My own view, based on experience, is that such an assumption is definitely not always a valid one.

Oh indeed. Something like this should be taught in lesson one..

“When I choose a cable colour,’ Humpty Dumpty said in rather a scornful tone, ‘it means just what I choose it to mean — neither more nor less.’

’The question is,’ said Alice, ‘whether you should make the same colours mean so many different things.’

With apologies to Lewis Carroll and "Alice through the Looking Glass" (electrical edition).

Having 'identified' the correct wire, now check with a meter..

Mike.

mapj1 said:

but the installation is already a little odd in  having a blue third phase - with that, I'd have expected to see an old German style red earth in that case

The OP's top thread said "brown,black,blue being the phase wires and green/yellow" - which almost sounds like they're used fairly modern (harmonized) 4-core cables - I think our 4-coure flexes were brown/black/blue/gy before we got grey introduced with the latest round of harmonization at which point I think they turned brown/black/grey/g-y.

   - Andy.

mapj1 said:

but the installation is already a little odd in  having a blue third phase - with that, I'd have expected to see an old German style red earth in that case

The OP's top thread said "brown,black,blue being the phase wires and green/yellow" - which almost sounds like they're used fairly modern (harmonized) 4-core cables - I think our 4-coure flexes were brown/black/blue/gy before we got grey introduced with the latest round of harmonization at which point I think they turned brown/black/grey/g-y.

   - Andy.

but its not actually any of the VDE recognized colour schemes ;-)

But probably correct.
I have always been very wary of colours on the continent, especially red, and not very trusting of them here either..

Worst ever was a colleagues  Greek wired 3 phase pump. Brown phase 1, blue phase 2, green yellow phase 3.... can we guess what happened here !
M.