MCB Tripping

[kai]

Now That's what I'll call an Earth Fault - Literally!.

 

[Click-Sure]

Compost Fault Loop Impedence?

GaryMo, know what you mean, when you find that awkward fault by combined testing and experience, you feel like the best electrician in town for a couple of minutes.

At least I do!

 

[GaryMo]

Aim higher - the best in the world!

 

[scousespark]

Just been to look at the fault! Put a 250v IR test across all cores and got 0.01 ohms! Looked around the outside of the house and found an outside light with a 3core flex coming out of it feeding a standard 13A double socket lying in a pot full off damp compost!
Dissconnected cable from fitting and bingo 200 Megohms between all cores!
Cowboys!
Thanks for everyones help!

I'd be surprised if an electrician had wired the DSO from the light.
However, the term cowboy could easily apply to an electrician who goes to a job, where the client has an intermittent trip on an MCB, doesn't test but flicks it on and goes home as the lights are working.

Also, the voltage for an IR test is 500V.