RCD's is something I'm not familiar with but unfortunately when they wire houses in the Philippines, even new ones under permit like mine, they don't run ground/earth wires to any receptacle. I did run a line to a ground rod from the neutral in the breaker box, neutral was provided from the electric company but since 220 is the universal voltage here not sure why they did it unless they expected the electricians to ground the electrical system. When I took possession of the home a few ears ago I found they had buried the incoming line in orange plastic flex and twisted the wires together and taped them. Wire nuts are not widely used nor are other connections hardware so I had to ship a lot of stuff from the U.S.
In the U.S. we have GFCI (ground fault circuit interrupt) within 6 feet of running water and arc fault circuit breakers for all bedrooms. Arc faults trip faster when an arc is detected like sawing thru a wire in a wall, nails, screws, child with a paper clip etc.
The diode thing I may abandon since it's hard to charge from 2 2400w solar charge controllers, a 2400w windmill and 24v 3000w backup genny and get past the diode and keep battery banks separate.