1mm 18.10 Table B1 GN3Don't know the 1.0mm resistance of
Discuss High Zs value with 2 sockets in the UK Electrical Forum area at ElectriciansForums.net
1mm 18.10 Table B1 GN3Don't know the 1.0mm resistance of
I think a return to the property on monday and get some socket fronts off....
I put the pre test on the price but told him any faults would need rectified and would be extra.Is the customer paying for all these pre test.?
If you are measuring the rfc loop e2e and it's made from 2.5 /1.5 then these seem ok to me as 0.49x2.5/1.5 = 0.817, so practical reading of 0.83 gets a tickTheres 2 rings in the bungalow. One for the kitchen and one for the rest of the house Kitchen readings were r1 0.49 rN 0.49 r2 0.83. So even these figures seem a bit high then? MFT has been calibrated recently and checked it against my Cal card the other day.
Yep, 0.46 was my highest value in the kitchen. My calcs work out for the other ring (apart Zs sockets) work out, but r1 r2 & rN values are high if you put them against cable resistance table in GN3. See post 12 for other values.If you are measuring the rfc loop e2e and it's made from 2.5 /1.5 then these seem ok to me as 0.49x2.5/1.5 = 0.817, so practical reading of 0.83 gets a tick
This would indicate an rfc about 65m length end to end and added to your Ze 0.14 should give Zs of around 0.47 ish which is fine for 32A. Is that roughly the Zs you've measured?
Is the customer paying for all these pre test.?
No but the electrician needs to do some, or he/she will pay for them in the long run
Td to end is a bit higher than expected calculation of 1.55 this may be down to loose/bad connection or 1.0mm cpc(or in part of) that aside did you do a R1 +R2 dead test this will prove that these two sockets are spurs. Midwest posted a good point in post #21 put the ends together at the C.U. and do a ring test at the high reading socket will prove it. You posted that there was still two cables at the highest reading socket my feeling is that there is another socket/outlet from this you have not located maybe in loft just a thought. Let us know what you find out on MondayThe socket with the highest reading had 2 x 2.5 T&E. Took L-L, N-N, E-E reading at the consumer unit. r1 + r2/4 + Ze = 0.82 Ze was measured at 0.14. The calculated Zs of 0.82 was very near what i was getting all around the ring. 2 sockets were a bit lower (0.45 & 0.55) and apart from the 2 that were high, the rest were virtually spot on. ( My end to end values were L=0.92 N=0.92 E=1.83)
I hope its not in the loft, its covered in insulation. Two layers, And there's hardly any space to move....Td to end is a bit higher than expected calculation of 1.55 this may be down to loose/bad connection or 1.0mm cpc(or in part of) that aside did you do a R1 +R2 dead test this will prove that these two sockets are spurs. Midwest posted a good point in post #21 put the ends together at the C.U. and do a ring test at the high reading socket will prove it. You posted that there was still two cables at the highest reading socket my feeling is that there is another socket/outlet from this you have not located maybe in loft just a thought. Let us know what you find out on Monday
Reply to High Zs value with 2 sockets in the UK Electrical Forum area at ElectriciansForums.net