Confused readings testing TT Ze with fluke 1653

[telectrix]

solution. use the PME buyt leave the rods in just in case . sssimpleess.

 

[brucelee]

use the TN-C-S then your Ze will be below 0.35 ohms or should be lol so the PFC will be a lot better and not jsut relying on a RCD to hopefullly work and disconnect in the required time

I used a 6mm 3 core swa to supply my bruvs shed a run of about 30 metres and all Zs comply so the RCD is only there for additonal protection this job was used for my assessment I wanted to use 10mm to lower Vd as it was close in the end with final circuits for the lights but within the 3% max and the 5% for power for the sockets and 4mm swa 3 core which then feeds a double socket and FCU on decking all comply with Zs, and Vd
I am with ELCSA and was given was awarded an A and congratulated on my design

 

[Engineer54]

Now, what's the betting that the DNO earthing system has been left at the house??

I just knew that he had left a perfectly good earth at the house and was struggling to get a decent Ra level with a rod!!

Forgive the Pun, but your just making a rod for your own back. Leave the rod in the ground and it's connection to your garage CU and use that PME earth connection at the garage CU. Forget all the scaremongery you've been told it's rubbish. There is nothing wrong with extending a PME earth out to a garage, where you will have a very respectful min Ze of 0.35 ohms or thereabouts, rather than a limp 115 ohm Ra!!

 

[Paul Willoughby]

Took advice and used PME earth at garage with 3rd core and by SWA Gland to earthing terminal, zs at db reading of 0.45 ohms.

Just confirming this is acceptable as this reading would now be Ze of the TNCS supply + R1+R2 of the SWA.

Yes?

 

[spark 68]

Now Zdb at your sub-board, which is Ze (at origin) + (R1+R2) of your sub-main (armoured cable).

You only have one Ze, this is at the origin

 

[Paul Willoughby]

Now Zdb at your sub-board, which is Ze (at origin) + (R1+R2) of your sub-main (armoured cable).

You only have one Ze, this is at the origin

thanks for confirming, finally got it now...