Comparing ELCBs to RCCBs to RCBOs

It can depend a bit on who is using these acronyms, but FWIW :

ELCB = Earth Leakage Circuit Breaker

RCCB = Residual Current Circuiit Breaker

RCBO = Residual Current circuit Breaker with Overcurrent protection

I believe that ELCBs are used in power distribution networks.

In the field of low voltage ac switchgear RCCBs provide the pure residual current protection for one or more final subcircuits in a switchboard, usually in conjunction with miniature circuit breakers (MCBs). RCBOs integrate the RCCB function and the MCB function into one handy device.

For diagrams & specs, I suggest you surf around the GE, Schneider, ABB ... websites, they are generally bristling with downloadable catalogues and the like.

ELCB (Earth Leakage Circuit Breaker) & RCCB (Residual Current Circuit Breaker) are one and the same. The diference is only in the nomenclature followed in different countries. The purpose is to provide protection against earth leakages which might be harmful to life and/or the installation. An ELCB or RCCB does not provide protection against overload or short circuit.

Whereas an RCBO is Residual Current Circuit Breaker with Overload Protection. It is in fact a combination of an MCB & an ELCB/RCCB. It offers protection against Over load, Short circuit & Earth Leakage.