E
Engineer54
I don't want to sound pedantic here but I feel it's important to make a distinction between Voltage Operated Earth Leakage Circuit Breakers (VOELCB) and Current Operated Earth Leakage Circuit Breakers.
The current operated devices are actually what we now know as RCD's but were badged as ELCB's when they were first produced and as long as they pass the usual instrument/functional tests, are fine to remain in service.
The voltage operated (yellow test button and terminal labelled 'frame') need to be replaced.
Agree.... but in this prticular case the OP did state that whatever the device is ....it wasn't working, so it needs replacing. especially as it's installed on a TT system.