Find electrician to trace earth leakage

[Octopus]

One year ago, not 10!
Main leakage was neutral to earth, not live to earth.
And lots of fun finding extension leads with surge protection stuffed behind beds.
Now all clear for new CU - thanks @Wilko

Interesting update. When you say all clear what are your ir readings now?

Fyi surge protection devices, rcd's and appliances will all give low and false IR readings ...

 

[Wilko]

Interesting update. When you say all clear what are your ir readings now?
Fyi surge protection devices, rcd's and appliances will all give low and false IR readings ...

Yes indeed, it did take a few searches to find them all.
The kitchen ring L+N to E at 250V was initially too low to read on my meter, but not a dead short. Deleting the damaged cable brought the 2 radials to about 200M. By conclusion the global IR at 500V was 40M Ohms.

 

[Pete999]

In reality no, but members of the public are encouraged to use accredited tradesmen because it supposedly gives them more assurance about the quality of workmanship.
As a landlord I have to be able to show that I took reasonable care in having my home tested (and soon worked on) by someone competent to do the job.

And there lies the problem.

 

[Octopus]

Hi All - @naylorpd was mad kind enough to let me in for a look at the problem.
On arrival, clamping the tails did reveal a standing leakage of 70mA so there was likely to be a problem to solve. It turns out a fried USB outlet and a kitchen RFC fault were the major contributors. Fixing these two has reduced the installation leakage to 10mA with all appliances and boiler running etc.
The installation is 1980 (ish) TNCS PME , controlled by the original Wylex board with push button 5,15 and 30A mcb. There was a new kitchen fitted 10 years ago and one of the wall units has a mounting point in the middle of the cable safe zone. And sure enough probing the bracket through the back of the cupboard showed connection to the ring. Due to domestic practicalities we decided to deal with Kev's Revenge by disconnecting the damaged section for now. The RFC is now 2 radials with 15A OCPB, until a more convenient time to dismantle the kitchen, dig out the cable and repair it.

That's top feedback mate ............ Shame the chap who did the EICR wasn't as diligent.