Why we dont use rcbo's more redily I will never know
I think we're in something of a Catch-22 situation at the moment. People will balk at installing RCBOs until the prices come down on them, but the prices won't drop until they're more widely used.
Modern split-load boards help, but they're not without their own problems out here in rural TT-earthing land. By the time you factor in a 100mA time-delay RCD for the main on top of the 30mA RCD sub-main, it can start getting quite expensive.
There's always the option of converting to PME and installing a "normal" split load board, but that's likely to be just as expensive when much of the bonding then needs to be upgraded.
There are still a
lot of houses around here on TT with an old voltage-operated ELCB.
