Hi, can any one tells me why thunder tripping RCD, and how can I solve this problem?
Thanks and regards Wayne

Where do you live? RCD terminology is not widely used in the US. We use A GFCI which is basically the same. I don't think thunder is the problem, I think it is the lightning. You are either getting a surge or ground fault that is tripping the unit. Is it outside? Does it get wet? That's a common problem when water gets inside. Make sure that grounding is properlyconnected in the box, the unit stays dry and all ground wires in the outlet box are connected.

Yes, RCD is short for Residual Current Device, the European equivalent to the USA GFI device.

Here is a RCD manufacturer that recognizes the issue with lightning causing nusiance tripping of RCD units.

http://www05.abb.com/global/scot/scot209.nsf/veritydisplay/7115a45a1e2da408c1256cbc0054f193/$File/2CSC421002B0201.pdf

Yes the rcd is inside in the consumer unit. Is the earth electrode which is outside but it is connected properly.

By the way thanks for the pdf file it is very help full and I think that's the problem. Thanks a lot Wayne