This setup will relay nurse call lamps and a Pfeifton across the site. It uses 1970s construction for a good reason…
https://www.youtube.com/watch?v=9kZ027QOtQA
(the noise is a pager transmitter signal)
the electric supply is TN-C-S (PME, where protective earth and neutral are combined)
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those two cables are undersized for a modern install but only UKPN can alter them and they charge a lot of money for that.
TN-C-S makes it easier for the Electric Company as they can use cable without a metal cover; but it has the disadvantage of any diverted neutral current from unbalance three phase loads + all the high frequency interference modern power supplies send down functional earth is thereby radiated in a loop via the neutral throughout the whole building.
Even worse, differences in earth potential between the PEN conductor and the building metalwork permit stray electric to flow throughout the site (including radio interference). It is not dangerous (that would trip the RCD) but a nuisance as there is enough electricity to upset sensitive systems like computer networks which only use a couple of volts.
I had to read the lot of it – a cahier is a French exercise book or engineers notebook (they are however of superior quality to those handed out at school in Britain and used well into adulthood).
There is no equivalent version in English.
OK it is not unreasonable the Professeur would write in his own language although the Soviet Union is blamed for introducing TN-C-S to Europe and China. I am not too sure about that as France and the Soviets worked on non military tech throughout the 1970s (they did to be fair invent a superior colour TV system to the rest of Europe); and TN-C-S/PME appeared suddenly around 1978 in areas of the London, Eastern, Southern and South Eastern Electricity boards which all shared engineering ideas with France…
I disconnected the -27V accu supply from the lamp panel; and turned out all the lights to my office/workshop upstairs. The other end of the lamps are still connected to the main building earth. if I touch the (disconnected) accu supply which normally feeds the lamps; the stray current lights the LEDs! It is not a lot and might not be DC (most likely a combination of rough harmonics) but just shows how much rubbish gets into a TN-C-S system. This is also why I use 1970s era German standard relays; as they need at least 30mA to pull in (stray electric would have put off the RCD before then)
Apologies for the shaky video; I had to do this late at night and quickly before the nurses wondered why all the lights were out upstairs and I caused a panic as theyd probably think I had managed to get myself sparked from 230V…
GL you’re a genius.
Almost probably a genis. The fact you seem to be allowed tp have whatever you bloddy well want to do god only know with seems to prove it.
I am no way smart enough for “genius” level – it is just I grew up in 1970s/80s where you had to learn stuff from basic principles; as well as have some knowledge of other languages which was always the case until the 21st century.
There were two good bits of advice my Professor friend told everyone – the first is when you are faced with something which looks complicated; start with what you do know and use this to split the system into smaller pieces that can be individually tested.
The second was that he believed small children should be encouraged to experiment at an early age and even receive a few strong but non-lethal electric shocks and see what happens if low voltage circuits are accidentally sparked from L+ or L- to M/FE (earth) – these teach them to respect electricity. He did say that might have been a factor in his divorce; but his sons and daughters are all alive and well.
The Dutch, Germans, French, Belgians, Danes and Norweigians have the same attitudes which is why try and keep up with my languages as if you confine yourself to the Anglosphere you only get a limited amount of info or end up having to translate it from American and convert everything to metric so I might as well have read it in NL/DE/FR/DK/NO to start with.
It isn’t going to get me into Heaven either – other than to fix up defective communications equipment or add more repeater masts (I expect smartphones are now allowed in all afterlifes provided they are not used for anything sinful – provided they are silent they are now permitted in Catholic Churches, Mosques and Buddhist temples)
After many late nights reading the French cahier; UKPN earthing scheme and listening to Radio Maria (where Vincent reads the Chronicles or Narnia in Dutch at some random hour and plays English choral music) I envisaged new mast provides as being sent to some random outdoor place, where everyone on the work party (which could equally include Abdul and Ahmed) is closely watched by a foreman from Yorkshire + glared at random cats (some of which may have wandered over from foreign Heavens but are all annoyed because you’ve dug up their favourite chilling out place) – with the dude singing the specifications like a hymn accompanied by the cats.
“And Thou shalt bury; a grid of Copper,
At least a Metre, below the Firmament”
(miauw)
And once you are done with that an entire load of German Nuns arrive and the equivalent of BNetzA and check the grid is of sufficient dimensions, hasn’t got mangled in installation, correctly earth bonded to the mast and any electric supply earthing terminal; then everyone has to set up the equipment cabinet fill the big hole in and replant all the flowers; shrubbery and everything else that was previously there before the Nuns and Commnication Ministry visit again to check it once more. It might be better than being clouted with a rod of iron which can happen to some disbelievers but is stil hard work.
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