RCD on 2 socket unit wont turn on...

[Crazi]

Hi - see pic. I have a two sockets RCD unit that is wired in to downstairs sockets on the main board. The 2 socket unit RCD keeps tripping even with nothing plugged in. So I bought a new two socket RCD unit and it's doing the same! The main house RCD is fine. It does trip once in a while when trying to turn on the new RCD 2 socket unit but generally is fine.

The old 2 socket unit never tripped the main unit when trying to get it to work.

There is only half a metre of cable from one unit to the other. Its been fine for 15 years. All cables are tight...

Baffled...???

 

[Crazi]

PS. The 2 socket unit is connecting to the very left trip switch...

 

[EFLImpudence]

Do you mean the very left on the non-RCD side?
I now see not.

Take out the plug and try again.

 

[markyd1]

Why are there 3 cables in the far left 32a breaker and one looks like a 1.5mm?

 

[Crazi]

The plug is out. Just trips every time and now and again trips the main RCD as well.

I just removed the electric cable and checked it and it's fine so re-installed.

Totally weird!

I'm thinking just to put in a standard double socket. The downstairs toilet is connected to one socket and external house camera to the other. As both go through downstairs socket trip and the house has an RCD...should be safe enough?

 

[Taylortwocities]

The 30A MCB Is already RCD protected. Why do you think you need a 30mA protected socket as well??

 

[Crazi]

That's the cable feeding the double RCD socket

 

[Crazi]

When the people installed the downstairs toilet - they installed that 2 socket RCD. I just assumed it was needed but now thinking not...

 

[markyd1]

That's the cable feeding the double RCD socket

well if it is 1.5mm its too small for a start....when you say you tested the cable did you do an IR test

 

[EFLImpudence]

You don't need two RCDs on the same circuit, so swap for an ordinary socket.

If the RCD in the CU trips then something is wrong.


The socket RCD shouldn't trip with nothing plugged into it.

 

[Crazi]

Tested continuity resistance on my meter. Was zero ohms as expected.

 

[Crazi]

Just put in a normal double socket and everything is good

 

[markyd1]

between all 3 cores?

 

[markyd1]

Yes all is good...But if that cable is too small it needs changing...then will need a test cert,,,get an electrician Just because it works doesnt mean its right

 

[Crazi]

Yes... earth installed too