Mains tripping RCD in shed.

[PondMan]

Hello all,

My shed is supplied by a spur taken from the nearest upstairs socket with twin and earth to a double socket in the shed.

From that double socket I have one 4 way extension lead that has a pond pump (60Watt), UV light (15Watts) and a little air pump (unsure of the Watts).
I`m now setting up a smaller pond using another 4 way extension lead from the double socket, using pond pump (60Watts), UV light (8Watts).

I changed the double socket for a double RCD socket, but when I turn the mains back on and test the RCD as directed the little window stays white, if I fit back the old double socket it works.

I`ve wired a short 3 core lead to the RCD and tried it in another socket inside and the RCD window goes red, so the RCD is ok.

I`ve made sure all cables into the socket the spur comes from are secure.

Any ideas ??

Thank you.

 

[Spark123]

Athough the normal double socket in the shed is working, I'm wondering if there is a problem with the earth (CPC) to it. It will be more apparent with proper electrical test instruments, might be an idea to have an electrician take a look.