Can anybody assist, re the photos. Wondering if this is a TNS or TNCS system.
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TNS OR TNCS
- Thread starter DARTHVADER
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You have to ask the DNO, mate. There's NO WAY to tell for sure just by looking at the head.
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That's what I thought re the label for PME, but cant see one ? I'll check with local DNO.
Thanks for replies.
Thanks for replies.
Hi all.
Got a quick response back from the dno...they couldn't advise exactly! but the electrician would know what type it was. The girl at the DNO advised likely TNS given the area I'm in.
A PME upgrade if required would be £154.
So still none the wiser.
Got a quick response back from the dno...they couldn't advise exactly! but the electrician would know what type it was. The girl at the DNO advised likely TNS given the area I'm in.
A PME upgrade if required would be £154.
So still none the wiser.
might get shot for this one but:-
Why not have the Ze checked, if it less then 0.35, treat the install as PME anyway.
Why not have the Ze checked, if it less then 0.35, treat the install as PME anyway.
i think you are b/s'ing us with that
ah, no, you're telling the truth
typical response. Phrased a different way- 'we don't want to know unless someone is going to pay us, even if it is our responsibility to ensure any services we provide to you are functional. We don't like helping and we're not sorry. You little fish, we big fish, so wotcha gonna do??
''
at this point, did you hear any coins bouncing on a desk and someone in the background shouting either 'heads' or 'tails'
bout right for a 15 minute job
My money is on TN-S by the size of the cable and the external henley.
You could do a loop test on the N and E and if see how dis-similar they are, you could snip, but the best way is a call to the DNO.
You could do a loop test on the N and E and if see how dis-similar they are, you could snip, but the best way is a call to the DNO.
Thanks for replies.
One electrician has looked at this today (my neighbour) and he is not sure.
The reason being is there is a 6mm 3 core armoured cable buried ready to take supply to a log cabin, once purchased ! Spark initially advised he would need to know earthing, as to if it goes back to mcb board, or earth rod in garden.
Like your comments mikhailfaradayski, you have obviously been there a 1000 times !
One electrician has looked at this today (my neighbour) and he is not sure.
The reason being is there is a 6mm 3 core armoured cable buried ready to take supply to a log cabin, once purchased ! Spark initially advised he would need to know earthing, as to if it goes back to mcb board, or earth rod in garden.
Like your comments mikhailfaradayski, you have obviously been there a 1000 times !
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As already stated it is impossible to ID a TN-S supply as it could be combined anywhere on system for example next doors house and it would become TN-C-S.
The supply company have a duty to tell you what it is. They are the only people who can.
Why does it matter? If it is declared as a TN-S then ELI has to be better than 0.8 and if declared as TN-C-S then it has to be better than 0.35 which in days before RCD could make a difference but with RCD's on buried cables even if TN-S it would be very unlikely that you would be over the limit.
In any case most people today use an earth loop impedance tester the idea of measuring the resistance and calculating the ELI went out with the arc.
As to charge to change to TN-C-S one unlikely they could even if the wanted as all properties from same transformer would also need changing and so I would assume the girl on the phone hadn't a clue.
The question what type of supply do I have is a standard question asked when we find it's TT and 9 out of 10 they have to send some one out to check. On arrival you drop it in conservation that next door is TN-C-S and 9 out of 10 they will make yours TN-C-S without charge. As a result I know they have to tell you when asked what type of supply you have.
However I would be a lot happier with TN-S than TN-C-S so can't see why anyone would want it changing?
As to PME that is same as TN-C-S seems to be some confusion on earlier post.
So please tell why do you want to know. Are you going to serve petrol of something?
The supply company have a duty to tell you what it is. They are the only people who can.
Why does it matter? If it is declared as a TN-S then ELI has to be better than 0.8 and if declared as TN-C-S then it has to be better than 0.35 which in days before RCD could make a difference but with RCD's on buried cables even if TN-S it would be very unlikely that you would be over the limit.
In any case most people today use an earth loop impedance tester the idea of measuring the resistance and calculating the ELI went out with the arc.
As to charge to change to TN-C-S one unlikely they could even if the wanted as all properties from same transformer would also need changing and so I would assume the girl on the phone hadn't a clue.
The question what type of supply do I have is a standard question asked when we find it's TT and 9 out of 10 they have to send some one out to check. On arrival you drop it in conservation that next door is TN-C-S and 9 out of 10 they will make yours TN-C-S without charge. As a result I know they have to tell you when asked what type of supply you have.
However I would be a lot happier with TN-S than TN-C-S so can't see why anyone would want it changing?
As to PME that is same as TN-C-S seems to be some confusion on earlier post.
So please tell why do you want to know. Are you going to serve petrol of something?
Hi thanks for the reply, as I said spark asked me to find out as the earthing at the log cabin.Thanks.
ericmark, sorry for the stupid question but when you say a measurement better than 0.35 or 0.8 is needed, using TNCS as the example, is an ELI measurement of 0.30 better or worse than 0.35.
I ask out of interest and also if 0.30 is better than 0.35 isnt it better to treat every TN system as a TNCS as this is a lower threshold.
I ask out of interest and also if 0.30 is better than 0.35 isnt it better to treat every TN system as a TNCS as this is a lower threshold.
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