Extension cable tripping what I think is the RCD

Calahonda52

Borrowed an extn lead yesterday afternoon in the dark from a neighbour and when I plugged in a light to it, it tripped the double pole thing on the board.

Not the MCB

Went and bought one, all good.

When the unit below is plugged into the faulty extn , all three green come on and the board does not trip until something else is plugged into it.

Would welcome any thoughts as don't want to give it back without knowing what the issue is.

Thanks as always

kirk.

Probably N-E reverse

10-10-20

"Double-pole thing"... would that be the main breaker or did it have a "test" button on this breaker?

I'm thinking it might have been a short due to a cable insulation fault.

Calahonda52

Thanks guys, will check it when home next

Bruthal.

Possible N E reversed alright. Tester takes too low a load to trip RCD with that scenario so all will look OK on that tester once the phase is correct. Open plug of extension lead would be first check.

If that looks OK, try plug the lead into a twin socket then plug a kettle in the other socket and see if RCD trips.

kirk.

https://www.boards.ie/discussion/comment/121514786#Comment_121514786

A tester can't distinguish can it between N and E ?

A high-current fault loop test would trip an RCD

Bruthal.

https://www.boards.ie/discussion/comment/121514804#Comment_121514804

No can't I wouldn't think.

The L E and L N reversal displays is based on the phase being in the N pin and assumes the N is in the phase one then. If phase was in N terminal and E was in phase terminal and N in E of socket the tester is plugged into, it would display P N reversed etc.

Antenna

https://www.boards.ie/discussion/comment/121514786#Comment_121514786

Or else N touching E due to insulation worn off somewhere. Will trip RCD under sufficient load as some of the N current goes on the E conductor

kirk.

I dug out an old Robin 3-wire fault loop tester

Thought maybe my brain was deceiving me but no there's no N-E reversal led on it

Bruthal.

https://www.boards.ie/discussion/comment/121515210#Comment_121515210

The earlier mentioned extension lead plugged Into a twin socket and kettle in the other socket beside it was the idea to test, to show that up.

Bruthal.

https://www.boards.ie/discussion/comment/121515360#Comment_121515360

Yea I just noticed now that it actually says on the tester in the thread, that it can't detect N E reversed. As said though, L E reverse indication assumes the N is not swapped with E as well, and vice versa.

kirk.

Could be it's not the lead at all , hard to say

N-E reverse isn't something you'd expect on a lead

That would mean the neighbour had non -working RCD or none

kirk.

Any updates on this op

Is the lead gone away for forensic analysis?