High TNS readingssssss

[richy3333]

@buzzlightyear I think we drink similar shandy

 

[PEG]

I'm having an awful holiday,here.....lights and telly keep going off...

 

[Bradley6969]

Not changed any glands yet and only going by EICR at the moment, so I’m getting 1.13 ohms on earth loop but if I go to PSC L+N is 0.26 so may get round it that way as will still disconnect in required time, have 63amp 60898 MCB at mains DU then feed the caravan boxes

 

[Bradley6969]

It would be good if the OP could clarify the test results and what they mean by original values. Their other threads recently about this same job make me think these original values refer to the EICR conducted before they started the remedials rather than referring to an EIC.

Yes sorry

 

[Bobster]

TNS system
60947-2 main switch
60898 double pole 63amp MCBs that feed some caravan boxes now some circuits I can get below the disconnection times of 0.56 ohms but some are 1.22 ohms now I’ve tried changing glands anything else I can do apart from TT the hook up unit? Or do you need upfront RCD

If not change the distribution unit feeding boxes with RCD and Rod it

Not changed any glands yet and only going by EICR at the moment, so I’m getting 1.13 ohms on earth loop but if I go to PSC L+N is 0.26 so may get round it that way as will still disconnect in required time, have 63amp 60898 MCB at mains DU then feed the caravan boxes

You're contradicting yourself.

PSC L+N is 0.26 so may get round it that way as will still disconnect in required time

What do you mean by this then?

 

[Bradley6969]

You're contradicting yourself.



What do you mean by this then?

Sorry meant to put I’ve not tried changing any glands yet

Well calculates the max current flow between L+N same as earth loop between L+E in the event of a fault?

 

[Bobster]

Sorry meant to put I’ve not tried changing any glands yet

Well calculates the max current flow between L+N same as earth loop between L+E in the event of a fault?

Ok, but what has that got to do with Zs requirements?

 

[Baddegg]

So you’ve taken pscc at the origin and your testers also give you a Ze reading but that would include any parallel paths as well? I’m so confused.....did you take Ze with main earth disconnected?
I’d go with Petes post a while back and get some R1-R2 readings from the swa....

 

[Bradley6969]

Ok, but what has that got to do with Zs requirements?

Well you do a Zs at a panel/consumer so PSCC and PFC and record highest what’s difference but just another sub circuit? As if you measure either of these on my tester you get impedance value and kA so breaking capacity?

 

[Bobster]

Again, what has PSCC and PFC got to do with the Zs requirements?

Either I am misunderstanding the point you are trying to make, or you don't fully understand the difference in tests and what to do with the results.