Possible linked rings - or not

[IJWS15]

Am decorating the study and had some sockets off to wallpaper. Put them back on and the RCD tripped as I was refitting them.

Two ring circuits on the RCD and with both off the RCD would reset, with either on the RCD would not reset. The house is split side to side not top to bottom.

Went back round the sockets I had refitted and on one I had put the neutral in the earth, should have checked more carefully. Corrected it and the RCD reset with both breakers on.

My initial thought was that the rings may be linked but having mulled it over a bit am I correct that a neutral earth fault anywhere on an RCD protected circuit, energised or not, can cause the RCD to trip if another circuit protected by the same RCD is energised?

 

[ebee]

There has got to be some current thru the RCD to trip and there should be some imbalance to trip it.

If any circuit on one RCD is drawing current and the (common) N is connected to E then some of the N current would find its way to E rather than going thru the RCD therefore it could trip it.

 

[Taylortwocities]

It is explained in the WIKI, like most things.

Check out the RCD section. Here's a pretty picture.
Thanks to Bernardgreen!

Neutral_Earth_trip

• bernardgreen
• 16 Jan 2011
• 48