1.2-4 4×35×1500mm angle irons should be inserted into any wet place around the room for grounding devices and the distance between them will be 1 meter. And then lead each one out of the ground with 3×30mm flat files to form a good grounding net.

Test ground resistance with instruments after grounding and the standard resistance should be 3-5 W.

After testing the resistance, connect to the lead-out end of the grounding net with one end of one RVV2.5mm2 copper core and the other end with electric equipment and the grounding hole of the socket.

Installation steps:

Find a wet place around the room to dig a 1.5m2×300mm field surface and then insert the prepared angle iron into the earth. Then connect them to 3×30mm flat files by welding or with 8mm holes with screws (around the hole it should be filed with chisel and then lay on them with Vaseline). It should be lead out 2 meters higher than the ground and the grounding net should be covered with dirt.

Test the resistance to ground of the net with testor.

Drill an 8mm hole in the top end of the lead-out flat file and clean the surrounding area with chisels. Then lay on them with Vaseline and then tighten the lead and the flat file.

At last, connect the leader into the wire way of the user and add one grounding wire to the grid.