This is a good'un!!!!

[danspark12345]

So.

Went to test RCD with MFT at the socket. My meter alarmed and said reverse polarity. I then checked the connections, they were correct.

I then put my little plug in tester in and it showed something was wrong but doesn't say what. (Look at picture).

Baffled. I then check polarity at the board and the meter. All good.

I plugged my plug in tester into all sockets in the house. I had the same warning in every socket. This tells me the problem is upstream. But everything seems fine

 

[old_guy]

Is it possible all sockets have LN switched at the terminals?

 

[Rockingit]

I'm rashly assuming that you've checked the incoming tails at the CU aren't reversed?

 

[littlespark]

That’s the only bit we can’t visually check…. Meter to cu.

You can trace from the cutout fuse to meter… and from mainswitch to rcd within the board.


From the supply side of the mainswitch, what voltages do you get L-E and N-E?