RCD tripping instantly despite nothing plugged in

[ericmark]

Good point

 

[JohnW2]

Didn't think at time of first post but with a TT supply then earth neutral fault could trip RCD with no load.

As bernard has said, that's the same as a neutral to ground fault in a TN-C-S installation. However, as I said to him at the time, that would be a 'permanent' situation, the L-N imbalance in the RCD being largely related to what load current was being drawn from other installations on the same part of the supply network. In that situation, there is absolutely no reason why switching off a SP MCB supplying a totally unloaded circuit should stop the RCD trips occurring, is there?

Kind Regards, John

 

[securespark]

Have we established that all loads have indeed been disassociated?

 

[JohnW2]

Have we established that all loads have indeed been disassociated?

Well, that's what we've told. Everything unplugged and the boiler fuse removed (and probably its FCU switched off). I have repeatedly prefaced my comments with "IF all loads really have been removed...", or suchlike, and it obviously is not impossible that the OP has overlooked some load.

IF there really are no loads, and IF everything else we've been told is correct, then I can't see any explanation other than an L-E fault in the wring (either the cable itself, or at an accessory/JB), can you?

Kind Regards, John