Gents, in other parts of the world, ground (or earth) rods normally come in 1.8m lengths, and preferably solid copper. But they are threaded at both ends, and you buy a coupling to screw the lengths together .. and you buy a screw on pointy piece, and a screw on piece that you whack with a sledgehammer .. when you knock the rod in to ground level, unscrew the whacking piece, screw the next length on with a coupler, screw on the whacking piece. and carry on. The general idea is the the resistance to earth of the rod is equal to or less than 1 ohm. If you get into the water table, even better. If the resistance of a single rod is more than 1 ohm, knock in a second one about 2 metres away, and join them together with some 10 to 16 sq mm wire. Jubilee clips will work to fix the wire and rod together at a push. That gets you a good solid earth connection for the RCBO to work with. A UK company called furse have a catalogue online for all this earthing (grounding) stuff so you can see how it goes together.
Oh, and for God's sake, please make sure that all the electrical equipment is properly earthed (grounded).
European Schneider is good equipment, I would hope that the Thai Schneider is similar.
My reference ... I'm an electrical engineer on an oil refinery in the sandpit.