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@buzzlightyear I think we drink similar shandy
Discuss High TNS readingssssss in the Electrical Forum area at ElectriciansForums.net
Yes sorryIt 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.
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
PSC L+N is 0.26 so may get round it that way as will still disconnect in required time
Sorry meant to put I’ve not tried changing any glands yetYou'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?
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?Ok, but what has that got to do with Zs requirements?
Well the panel feeding the sub circuits has Zs of 3.15 and KA of 3.0 but some of the circuits are ok and some are not but there are endless joints underneath the ground so can’t help and glands are okIn order to get the values write in the being at the incoming what was the ohms and the ka.
Ovasly you have sub circuits to diffrant pitches ,the sub circuits are on bs60898 and you are testing each circuit ,but some how you are getting well beyond the max range .
Are the glands in good order or they
Are not earthed correctly.some how we are going round the caravan pictches if you know what i mean.
Yes, at a guess paralel pathsSo the Zs of the sub circuit is 1.22 ohm, the Zs at the panel feeding these is 3.15 ohm?
Yes, at a guess paralel paths
Supply goes in and out of gland plates?From where though?
Well the panel feeding the sub circuits has Zs of 3.15 and KA of 3.0 but some of the circuits are ok and some are not but there are endless joints underneath the ground so can’t help and glands are ok
Reply to High TNS readingssssss in the Electrical Forum area at ElectriciansForums.net
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